LTM4609IV#PBF

LTM4609 

## 36VIN, 34VOUT High Efficiency Buck-Boost DC/DC µModule Regulator 

## **FEATURES** 

- n **Single Inductor Architecture Allows VIN Above, Below or Equal to VOUT** 

- n **Wide VIN Range: 4.5V to 36V** 

- n **Wide VOUT Range: 0.8V to 34V** 

- n **IOUT: 4A DC (10A DC in Buck Mode)** 

- n **Up to 98% Efficiency** 

- n **Current Mode Control** 

- n **Power Good Output Signal** 

- n **Phase-Lockable Fixed Frequency: 200kHz to 400kHz** 

- n **Ultrafast Transient Response** 

- n Current Foldback Protection 

- n Output Overvoltage Protection 

- n Small Surface Mount Footprint, Low Profile 

   - (15mm × 15mm × 2.82mm) LGA and (15mm × 15mm × 3.42mm) BGA Packages 

- n SnPb (BGA) or RoHS Compliant (LGA and BGA) Finish 

## **APPLICATIONS** 

- n Telecom, Servers and Networking Equipment 

- n Industrial and Automotive Equipment 

- n High Power Battery-Operated Devices 

## **DESCRIPTION** 

The LTM[®] 4609 is a high efficiency switching mode buckboost power supply. Included in the package are the switching controller, power FETs and support components. Operating over an input voltage range of 4.5V to 36V, the LTM4609 supports an output voltage range of 0.8V to 34V, set by a resistor. This high efficiency design delivers up to 4A continuous current in boost mode (10A in buck mode). Only the inductor, sense resistor, bulk input and output capacitors are needed to finish the design. 

The low profile package enables utilization of unused space on the bottom of PC boards for high density point of load regulation. The high switching frequency and current mode architecture enable a very fast transient response to line and load changes without sacrificing stability. The LTM4609 can be frequency synchronized with an external clock to reduce undesirable frequency harmonics. 

Fault protection features include overvoltage and foldback current protection. The DC/DC µModule[®] regulator is offered in small 15mm × 15mm × 2.82mm LGA and 15mm × 15mm × 3.42mm BGA packages. The LTM4609 is available with SnPb (BGA) or RoHS compliant terminal finish. 

All registered trademarks and trademarks are the property of their respective owners. 

## **TYPICAL APPLICATION** 

**30V/2A Buck-Boost DC/DC µModule Regulator with 6.5V to 36V Input** 

**Efficiency and Power Loss vs Input Voltage** 

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VIN CLOCK SYNC 99 6<br>6.5V TO 36V<br>10µF VOUT<br>50V VIN PLLIN VFCBOUT 10µF + 330µF 30V2A 98 5<br>50V 50V 97<br>ON/OFF RUN LTM4609<br>5.6µH 4<br>SW1 96<br>SW2 95 3<br>RSENSE<br>SENSE [+] 94 2<br>0.1µF R2 93<br>15mΩ<br>SS SENSE [–] ×2 1<br>92 EFFICIENCY<br>SGND PGND VFB POWER LOSS<br>91 0<br>2.74k 8 12 16 20 24 28 32 36<br>4609 TA01a VIN (V)<br>4609 TA01b<br>EFFICIENCY (%)<br>POWER LOSS (W)<br>**----- End of picture text -----**<br>


Rev. G 

1 

For more information www.analog.com 

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## LTM4609 

## **ABSOLUTE MAXIMUM RATINGS** 

## **(Note 1)** 

VIN .............................................................–0.3V to 36V VOUT ............................................................. 0.8V to 36V INTVCC, EXTVCC, RUN, SS, PGOOD .............–0.3V to 7V SW1, SW2 (Note 7) .......................................–5V to 36V VFB ............................................................ –0.3V to 2.4V COMP ........................................................... –0.3V to 2V FCB, STBYMD .......................................–0.3V to INTVCC PLLIN ........................................................ –0.3V to 5.5V 

PLLFLTR ................................................... –0.3V to 2.7V INTVCC ................................................................ –40mA Operating Temperature Range (Note 2) E- and I-Grades ....................................–40°C to 85°C MP-Grade .......................................... –55°C to 125°C Junction Temperature ........................................... 125°C Storage Temperature Range .................. –55°C to 125°C Solder Temperature (Note 3) ................................. 245°C 

## **PIN CONFIGURATION (See Table 6 Pin Assignment)** 

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TOP VIEW TOP VIEW<br>SW2 SW2<br>(BANK 2) (BANK 2)<br>M M<br>L L<br>SW1 VIN SW1 VIN<br>(BANK 4) K (BANK 1) (BANK 4) K (BANK 1)<br>J J<br>VOUT H VOUT H<br>(BANK 5) (BANK 5)<br>G RSENSE G RSENSE<br>INTVCC (BANK 3) INTVCC (BANK 3)<br>EXTVCC F EXTVCC F<br>E E<br>PGND D PGND D<br>(BANK 6) C (BANK 6) C<br>PGOOD COMP PGOOD COMP<br>VFB B SENSE [–] SS SGND RUN FCB PLLFLTRPLLIN VFB B SENSE [–] SS SGND RUN FCB PLLFLTRPLLIN<br>A A<br>1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12<br>SENSE [+] STBYMD SENSE [+] STBYMD<br>LGA PACKAGE BGA PACKAGE<br>141-PIN (15mm × 15mm × 2.82mm) 141-PIN (15mm × 15mm × 3.42mm)<br>TJMAX = 125°C, θJA = 11.4°C/W, θJCtop = 15°C/W, θJCbottom = 4°C/W, WEIGHT = 1.5g TJMAX = 125°C, θJA = 11.4°C/W, θJCtop = 15°C/W, θJCbottom = 4°C/W, WEIGHT = 1.7g<br>ORDER INFORMATION<br>PART MARKING*<br>PACKAGE   MSL   TEMPERATURE RANGE<br>PART NUMBER PAD OR BALL FINISH DEVICE  FINISH CODE TYPE RATING (NOTE 2)<br>LTM4609EV#PBF Au (RoHS) LTM4609V e4 LGA 4 –40°C to 85°C<br>LTM4609IV#PBF Au (RoHS) LTM4609V e4 LGA 4 –40°C to 85°C<br>LTM4609MPV#PBF Au (RoHS) LTM4609V e4 LGA 4 –55°C to 125°C<br>LTM4609EY#PBF SAC305 (RoHS) LTM4609Y e1 BGA 4 –40°C to 85°C<br>LTM4609IY#PBF SAC305 (RoHS) LTM4609Y e1 BGA 4 –40°C to 85°C<br>LTM4609IY SnPb (63/37) LTM4609Y e0 BGA 4 –40°C to 85°C<br>LTM4609MPY #PBF SAC305 (RoHS) LTM4609Y e1 BGA 4 –55°C to 125°C<br>LTM4609MPY SnPb (63/37) LTM4609Y e0 BGA 4 –55°C to 125°C<br>**----- End of picture text -----**<br>


- Contact the factory for parts specified with wider operating temperature ranges. 

   - *The temperature grade is identified by a label on the shipping container.. Pad or 

   - ball finish code is per IPC/JEDEC J-STD-609. 

- Recommended LGA and BGA PCB Assembly and Manufacturing Procedures 

- LGA and BGA Package and Tray Drawings 

Rev. G 

2 

For more information www.analog.com 

LTM4609 

**ELECTRICAL CHARACTERISTICS The** l **denotes the specifications which apply over the specified operating temperature range (Note 2), otherwise specifications are at TA = 25°C, VIN = 12V, per typical application (front page) configuration.** 

|**SYMBOL**|**PARAMETER**|**CONDITIONS**|**CONDITIONS**|**MIN**<br>**TYP**<br>**MAX**|**UNITS**|
|---|---|---|---|---|---|
|**Input Specifications**||||||
|VIN(DC)|Input DC Voltage||l|4.5<br>36|V|
|VIN(UVLO)|Undervoltage Lockout Threshold|VINFalling (–40°C to 85°C)<br>VINFalling (–55°C to 125°C)|l<br>l|3.4<br>3.4<br>4<br>4.5|V<br>V|
|IQ(VIN)|Input Supply Bias Current<br>Normal<br>Standby<br>Shutdown SupplyCurrent|VRUN= 0V, VSTBYMD> 2V<br>VRUN= 0V,VSTBYMD= Open||2.8<br>1.6<br>35<br>60|mA<br>mA<br>µA|
|**Output Specifications**||||||
|IOUTDC|Output Continuous Current Range<br>(Note 3)|VIN= 32V, VOUT= 12V<br>VIN= 6V, VOUT= 12V||10<br>4|A<br>A|
|ΔVFB/VFB(NOM)|Line Regulation Accuracy|VIN= 4.5V to 36V, VCOMP= 1.2V (Note 4)||0.002<br>0.02|%/V|
|ΔVFB/VFB(LOAD)|Load Regulation Accuracy|VCOMP= 1.2V to 0.7V<br>VCOMP= 1.2V to 1.8V(Note 4)|l<br>l|0.15<br>–0.15<br>0.5<br>–0.5|%<br>%|
|**Switch Section(Note 5)**||||||
|M1 tr|Turn-On Time|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||50|ns|
|M1 tf|Turn-Off Time|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||40|ns|
|M3 tr|Turn-On Time|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||25|ns|
|M3 tf|Turn-Off Time|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||20|ns|
|M2, M4 tr|Turn-On Time|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||20|ns|
|M2, M4 tf|Turn-Off Time|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||20|ns|
|t1d|M1 Off to M2 On Delay|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||50|ns|
|t2d|M2 Off to M1 On Delay|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||50|ns|
|t3d|M3 Off to M4 On Delay|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||50|ns|
|t4d|M4 Off to M3 On Delay|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||50|ns|
|Mode Transition 1|M2 Off to M4 On Delay|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||220|ns|
|Mode Transition 2|M4 Off to M2 On Delay|Drain to Source Voltage VDS= 12V,<br>Bias Current ISW= 10mA||220|ns|
|M1 RDS(ON)|Static Drain-to-Source<br>On-Resistance|Bias Current ISW= 3A||10|mΩ|
|M2 RDS(ON)|Static Drain-to-Source<br>On-Resistance|Bias Current ISW= 3A||14<br>20|mΩ|
|M3 RDS(ON)|Static Drain-to-Source<br>On-Resistance|Bias Current ISW= 3A||14<br>20|mΩ|
|M4 RDS(ON)|Static Drain-to-Source<br>On-Resistance|Bias Current ISW= 3A||14<br>20|mΩ|
|**Oscillator and Phase-Locked Loop**||||||
|fNOM|Nominal Frequency|VPLLFLTR= 1.2V||260<br>300<br>330|kHz|
|fLOW|Lowest Frequency|VPLLFLTR= 0V||170<br>200<br>220|kHz|



Rev. G 

3 

For more information www.analog.com 

## LTM4609 

**ELECTRICAL CHARACTERISTICS The** l **denotes the specifications which apply over the specified operating temperature range (Note 2), otherwise specifications are at TA = 25°C, VIN = 12V, per typical application (front page) configuration.** 

|**SYMBOL**|**PARAMETER**|**CONDITIONS**|**CONDITIONS**|**MIN**<br>**TYP**<br>**MAX**|**UNITS**|
|---|---|---|---|---|---|
|fHIGH|Highest Frequency|VPLLFLTR= 2.4V||340<br>400<br>440|kHz|
|RPLLIN|PLLIN Input Resistance|||50|kΩ|
|IPLLFLTR|Phase Detector Output Current|fPLLIN< fOSC<br>fPLLIN> fOSC||–15<br>15|µA<br>µA|
|**Control Section**||||||
|VFB|Feedback Reference Voltage|VCOMP= 1.2V(–40°C to 85°C)<br>VCOMP= 1.2V(–55°C to 125°C)|l<br>l|0.792<br>0.785<br>0.8<br>0.8<br>0.808<br>0.815|V<br>V|
|VRUN|RUN Pin ON/OFF Threshold|||1<br>1.6<br>2.2|V|
|ISS|Soft-Start ChargingCurrent|VRUN= 2.2V||–1.7<br>–1|µA|
|VSTBYMD(START)|Start-UpThreshold|VSTBYMDRising||0.4<br>0.7|V|
|VSTBYMD(KA)|Keep-Active Power On Threshold|VSTBYMDRising,VRUN= 0V||1.25|V|
|VFCB|Forced Continuous Threshold|||0.76<br>0.8<br>0.84|V|
|IFCB|Forced Continuous Pin Current|VFCB= 0.85V||–0.3<br>–0.2<br>–0.1|µA|
|VBURST|Burst Inhibit (Constant Frequency)<br>Threshold|Measured at FCB Pin||5.3<br>5.5|V|
|DF(BOOST, MAX)|Maximum DutyFactor|% Switch M4 On||99|%|
|DF(BUCK, MAX)|Maximum DutyFactor|% Switch M1 On||99|%|
|tON(MIN, BUCK)|Minimum On-Time for Synchronous<br>Switch in Buck Operation|Switch M1 (Note 6)||200<br>250|ns|
|RFBHI|Resistor Between VOUTand VFBPins|||99.5<br>100<br>100.5|kΩ|
|**Internal VCC Regulator**||||||
|INTVCC|Internal VCCVoltage|VIN= 12V, VEXTVCC= 5V<br>VIN= 7V,VEXTVCC= 5V|l<br>l|5.7<br>5.56<br>6<br>6<br>6.3<br>6.35|V<br>V|
|ΔVLDO/VLDO|Internal VCCLoad Regulation|ICC= 0mA to 20mA,VEXTVCC= 5V||0.3<br>2|%|
|VEXTVCC|EXTVCCSwitchover Voltage|ICC= 20mA,VEXTVCCRising|l|5.4<br>5.6|V|
|ΔVEXTVCC(HYS)|EXTVCCSwitchover Hysteresis|||300|mV|
|ΔVEXTVCC|EXTVCCSwitch DropVoltage|ICC= 20mA,VEXTVCC= 6V||60<br>150|mV|
|**Current Sensing Section**||||||
|VSENSE(MAX)|Maximum Current Sense Threshold|Boost Mode<br>Buck Mode|l<br>l|–95<br>160<br>–130<br>190<br>–150|mV<br>mV|
|VSENSE(MIN, BUCK)|Minimum Current Sense Threshold|Discontinuous Mode||–6|mV|
|ISENSE|Sense Pins Total Source Current|VSENSE–= VSENSE+= 0V||–380|µA|
|PGOOD||||||
|ΔVFBH|PGOOD Upper Threshold|VFBRising||5.5<br>7.5<br>10|%|
|ΔVFBL|PGOOD Lower Threshold|VFBFalling||–5.5<br>–7.5<br>–10|%|
|ΔVFB(HYS)|PGOOD Hysteresis|VFBReturning||2.5|%|
|VPGL|PGOOD Low Voltage|IPGOOD= 2mA||0.2<br>0.3|V|
|IPGOOD|PGOOD Leakage Current|VPGOOD= 5V||1|µA|



**Note 1:** Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. 

**Note 2:** The LTM4609 is tested under pulsed load conditions such that TJ ≈ TA. The LTM4609E is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the –40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. The LTM4609I is guaranteed over the –40°C to 85°C operating temperature range. The LTM4609MP is guaranteed and tested over the –55°C to 125°C operating temperature 

range. For output current derating at high temperature, please refer to Thermal Considerations and Output Current Derating discussion. 

**Note 3:** See output current derating curves for different VIN, VOUT, and TA. **Note 4:** The LTM4609 is tested in a feedback loop that servos VCOMP to a specified voltage and measures the resultant VFB. 

**Note 5:** Turn-on and turn-off time are measured using 10% and 90% levels. Transition delay time is measured using 50% levels. 

**Note 6:** 100% test at wafer level only. **Note 7:** Absolute Maximum Rating of –5V on SW1 and SW2 is under transient condition only. 

Rev. G 

4 

For more information www.analog.com 

LTM4609 

## **TYPICAL PERFORMANCE CHARACTERISTICS** 

## **(Refer to Figure 18)** 

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Efficiency vs Load Current  Efficiency vs Load Current  Efficiency vs Load Current<br>6VIN to 12VOUT 12VIN to 12VOUT 32VIN to 12VOUT<br>100 100 100<br>90 TI eS 90 “TI EA 90 Teo<br>80 BNI '72ca0081 80 Cece Til 80 FART<br>7060 RTyet ConnIIITCO 7060 aCeiM TC 7060 meIAEAN76NAAN<br>50 VAEEANN 50 V7 CTI CTI 50 Ta? UCC<br>40 22401 RO 40 AATCC TI 40 BS)sieANAIN<br>30 ZARA 30 30 VAN NA<br>20 HI 20 AAA nA 7AA<br>BURST BURST 20 SKIP CYCLE<br>10 CH DCM 10 PARI 0 DCM 10 Palin DCM<br>0 CC T=]CT CCM 0 0CCU aCT CCM 0 FaiaPTT CT CCM<br>0.01 0.1 1 10 0.01 0.1 1 10 0.01 0.1 1 10 100<br>LOAD CURRENT (A) LOAD CURRENT (A) LOAD CURRENT (A)<br>4609 G01 4609 G02 4609 G03<br>Efficiency vs Load Current  Efficiency vs Load Current  Efficiency vs Load Current<br>3.3µH Inductor 5.6µH Inductor 8µH Inductor<br>100 100 100<br>99<br>95 PT] ELIT Tid pit tt tt tt 99 Pt ty | fe<br>98<br>Eo 97 H+ 98 HCE<br>90<br>96<br>97<br>85 Vio RSS | 95 ULOG OLeee<br>< a) 7a 96 || wT | ft<br>94<br>80 AEE) eR /<br>93 WEEE 95 FL<br>75 Caan 12VIN TO 5VOUT 92 28VIN TO 20VOUT 94 | 30V | IN TO 30V | OUT<br>24VIN TO 5VOUT 91 i 32VIN TO 20VOUT 32VIN TO 30VOUT<br>32VIN TO 5VOUT 36VIN TO 20VOUT 36VIN TO 30VOUT<br>70 Haaa 90 ain 93 | aa | |<br>0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6<br>LOAD CURRENT (A) LOAD CURRENT (A) LOAD CURRENT (A)<br>4609 G04 4609 G05 4609 G06<br>Efficiency vs Load Current  Transient Response from   Transient Response from<br>3.3µH Inductor 6VIN to 12VOUT 12VIN to 12VOUT<br>100<br>95 Pt i | ft tl IOUT Yr]ee| ft ey yeeeey IOUT Yr|| | |eS| | ty fy yl<br>2A/DIV 2A/DIV<br>90 aneL—~~.~— eeACO eee P|a | | | i fet ft tf<br>VOUT VOUT<br>85 FL SINEEN 200mV/DIV REC IREEO 200mV/DIV See eee<br>80 P| | . yy fd PCTSSo 200µs/DIV ETE 4609 G08 SSa 200µs/DIV eee 4609 G09<br>LOAD STEP: 0A TO 3A AT CCM LOAD STEP: 0A TO 3A AT CCM<br>75 5VIN to 16VOUT OUTPUT CAPS: 22µF ×4 CERAMIC CAPS AND OUTPUT CAPS: 22µF ×4 CERAMIC CAPS AND<br>5VIN to 24VOUT 180µF ×2 ELECTROLYTIC CAPS 180µF ×2 ELECTROLYTIC CAPS<br>5VIN to 30VOUT 15mΩ ×2 SENSING RESISTORS 15mΩ ×2 SENSING RESISTORS<br>70<br>0 0.5 1 1.5 2 2.5 3<br>LOAD CURRENT (A)<br>4609 G07<br>EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%)<br>EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%)<br>EFFICIENCY (%)<br>**----- End of picture text -----**<br>


Rev. G 

5 

For more information www.analog.com 

LTM4609 

## **TYPICAL PERFORMANCE CHARACTERISTICS** 

**Transient Response from 32VIN to 12VOUT** 

**Start-Up with 6VIN to 12VOUT at IOUT = 4A** 

**Start-Up with 32VIN to 12VOUT at IOUT = 5A** 

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IOUT<br>2A/DIV<br>STCCEEECEoT<br>VOUT<br>100mV/DIV oNa |<br>PERE<br>200µs/DIV 4609 G10<br>LOAD STEP: 0A TO 5A AT CCM<br>OUTPUT CAPS: 22µF ×4 CERAMIC CAPS AND<br>180µF ×2 ELECTROLYTIC CAPS<br>12mΩ ×2 SENSING RESISTORS<br>**----- End of picture text -----**<br>


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IL<br>5A/DIV a<br>IIN<br>5A/DIV PEE Te<br>VOUT FE"|<br>10V/DIV a<br>50ms/DIV 4609 G11<br>**----- End of picture text -----**<br>


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0.1µF SOFT-START CAP<br>OUTPUT CAPS: 22µF ×4 CERAMIC CAPS AND<br>180µF ×2 ELECTROLYTIC CAPS<br>12mΩ ×2 SENSING RESISTORS<br>**----- End of picture text -----**<br>


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IL<br>5A/DIV COC Er<br>IIN<br>2A/DIV WOE ate<br>VOUT a<br>10V/DIV a<br>10ms/DIV 4609 G12<br>0.1µF SOFT-START CAP<br>OUTPUT CAPS: 22µF ×4 CERAMIC CAPS AND<br>180µF ×2 ELECTROLYTIC CAPS<br>12mΩ ×2 SENSING RESISTORS<br>**----- End of picture text -----**<br>


**Short-Circuit with 32VIN to 12VOUT at IOUT = 5A** 

**Short-Circuit with 12VIN to 34VOUT at IOUT = 2A** 

**Short-Circuit with 6VIN to 12VOUT at IOUT = 4A** 

**==> picture [505 x 130] intentionally omitted <==**

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a So VOUT ee<br>VOUT as 10V/DIV eae a<br>5V/DIV IIN otRIMeae PPPA<br>Fftt+titttea —— 2A/DIVVOUT a HCCAEATELrtol EEE<br>5A/DIVIIN SSSrT | 5V/DIV OSE 5A/DIVIIN EEELe<br>eo Bpiama ones TCO EE<br>PEE EEE 50µs/DIV TTT 4609 G13 Mens 50µs/DIV  ase 4609 G14 a 20µs/DIV 4607 G15<br>OUTPUT CAPS: 22µF ×4 CERAMIC CAPS AND OUTPUT CAPS: 22µF ×4 CERAMIC CAPS AND OUTPUT CAPS: 10µF ×2 50V CERAMIC CAPS AND<br>180µF ×2 ELECTROLYTIC CAPS 180µF ×2 ELECTROLYTIC CAPS 47µF ×2 50V ELECTROLYTIC CAPS<br>12mΩ ×2 SENSING RESISTORS 12mΩ ×2 SENSING RESISTORS 15mΩ ×2 SENSING RESISTORS<br>**----- End of picture text -----**<br>


Rev. G 

6 

For more information www.analog.com 

LTM4609 

## **PIN FUNCTIONS** 

**SENSE[+] (Pin A4):** Positive Input to the Current Sense and Reverse Current Detect Comparators. 

**SENSE[–] (Pin A5):** Negative Input to the Current Sense and Reverse Current Detect Comparators. 

**SS (Pin A6):** Soft-Start Pin. Soft-start reduces the input surge current from the power source by gradually increasing the controller’s current limit. 

**SGND (Pin A7):** Signal Ground Pin. This pin connects to PGND at output capacitor point. 

**RUN (Pin A8):** Run Control Pin. A voltage below 1.6V will turn off the module. There is a 100k resistor between the RUN pin and SGND in the module. Do not apply more than 6V to this pin. See the Applications Information section. 

**FCB (Pin A9):** Forced Continuous Control Input. The voltage applied to this pin sets the operating mode of the module. When the applied voltage is less than 0.8V, the forced continuous current mode is active in boost operation and the skip cycle mode is active in buck operation. When the pin is tied to INTVCC, the constant frequency discontinuous current mode is active in buck or boost operation. See the Applications Information section. 

**STBYMD (Pin A10):** LDO Control Pin. Determines whether the internal LDO remains active when the controller is shut down. See Operation section for details. If the STBYMD pin is pulled to ground, the SS pin is internally pulled to ground to disable start-up and thereby providing a single control pin for turning off the controller. An internal decoupling capacitor is tied to this pin. 

**VIN (Bank 1):** Power Input Pins. Apply input voltage between these pins and PGND pins. Recommend placing input decoupling capacitance directly between VIN pins and PGND pins. 

**RSENSE (Bank 3):** Sensing Resistor Pin. The sensing resistor is connected from this pin to PGND. 

**SW1, SW2 (Bank 4, Bank 2):** Switch Nodes. The power inductor is connected between SW1 and SW2. 

**VOUT (Bank 5):** Power Output Pins. Apply output load between these pins and PGND pins. Recommend placing output decoupling capacitance directly between these pins and PGND pins. 

**PGND (Bank 6):** Power Ground Pins for Both Input and Output Returns. 

**PGOOD (Pin B5):** Output Voltage Power Good Indicator. Open drain logic output that is pulled to ground when the output voltage is not within ±7.5% of the regulation point. 

**VFB (Pin B6):** The Negative Input of the Error Amplifier. Internally, this pin is connected to VOUT with a 100k precision resistor. Different output voltages can be programmed with an additional resistor between VFB and SGND pins. See the Applications Information section. 

**COMP (Pin B7):** Current Control Threshold and Error Amplifier Compensation Point. The current comparator threshold increases with this control voltage. The voltage ranges from 0V to 2.4V. 

**PLLFLTR (Pin B8):** The lowpass filter of the phase-locked loop is tied to this pin. This pin can also be used to set the frequency of the internal oscillator with an AC or DC voltage. See the Applications Information section for details. 

**PLLIN (Pin B9):** External Clock Synchronization Input to the Phase Detector. This pin is internally terminated to SGND with a 50k resistor. The phase-locked loop will force the rising bottom gate signal of the controller to be synchronized with the rising edge of PLLIN signal. 

**NTVCC (Pin F5):** Internal 6V Regulator Output. This pin is for additional decoupling of the 6V internal regulator. Do not source more than 40mA from INTVCC. 

**EXTVCC (Pin F6):** External VCC Input. When EXTVCC exceeds 5.7V, an internal switch connects this pin to INTVCC and shuts down the internal regulator so that the controller and gate drive power is drawn from EXTVCC. Do not exceed 7V at this pin and ensure that EXTVCC < VIN 

Rev. G 

7 

For more information www.analog.com 

LTM4609 

## **SIMPLIFIED BLOCK DIAGRAM** 

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**----- Start of picture text -----**<br>
VIN<br>4.5V TO 36V<br>EXTVCC C1 CIN<br>M1<br>INTVCC SW2<br>PGOOD M2 L<br>SW1<br>RUN<br>ON/OFF<br>100k VOUT 12V<br>4A<br>STBYMD CO1<br>M3<br>0.1µF COUT<br>100k RFB<br>COMP VFB 7.15k<br>M4<br>CONTROLLER<br>INT<br>COMP RSENSE<br>SS SENSE [+]<br>SS<br>0.1µF<br>PLLIN<br>INT RSENSE<br>FILTER<br>PLLFLTR SENSE [–]<br>INT<br>FILTER PGND<br>FCB<br>1000pF<br>SGND<br>TO PGND PLANE AS<br>SHOWN IN FIGURE 15<br>**----- End of picture text -----**<br>


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**----- Start of picture text -----**<br>
4609 BD<br>**----- End of picture text -----**<br>


**Figure 1. Simplified LTM4609 Block Diagram** 

## **DECOUPLING REQUIREMENTS TA = 25°C. Use Figure 1 configuration.** 

|**SYMBOL**|**PARAMETER**|**CONDITIONS**|**MIN**<br>**TYP**<br>**MAX**|**UNITS**|
|---|---|---|---|---|
|CIN|External Input Capacitor Requirement<br>(VIN= 4.5V to 36V, VOUT= 12V)|IOUT= 4A|10|µF|
|COUT|External Output Capacitor Requirement<br>(VIN= 4.5V to 36V, VOUT= 12V)|IOUT= 4A|200<br>300|µF|



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LTM4609 

## **OPERATION** 

## **Power Module Description** 

The LTM4609 is a non-isolated buck-boost DC/DC power supply. It can deliver a wide range output voltage from 0.8V to 34V over a wide input range from 4.5V to 36V, by only adding the sensing resistor, inductor and some external input and output capacitors. It provides precisely regulated output voltage programmable via one external resistor. The typical application schematic is shown in Figure 18. 

The LTM4609 has an integrated current mode buck-boost controller, ultralow RDS(ON) FETs with fast switching speed and integrated Schottky diodes. With current mode control and internal feedback loop compensation, the LTM4609 module has sufficient stability margins and good transient performance under a wide range of operating conditions and with a wide range of output capacitors. The operating frequency of the LTM4609 can be adjusted from 200kHz to 400kHz by setting the voltage on the PLLFLTR pin. 

Alternatively, its frequency can be synchronized by the input clock signal from the PLLIN pin. The typical switching frequency is 400kHz. 

The Burst Mode[®] and skip-cycle mode operations can be enabled at light loads to improve efficiency, while the forced continuous mode and discontinuous mode operations are used for constant frequency applications. Foldback current limiting is activated in an overcurrent condition as VFB drops. Internal overvoltage and undervoltage comparators pull the open-drain PGOOD output low if the output feedback voltage exits the ±7.5% window around the regulation point. Pulling the RUN pin below 1.6V forces the controller into its shutdown state. 

If an external bias supply is applied on the EXTVCC pin, then an efficiency improvement will occur due to the reduced power loss in the internal linear regulator. This is especially true at the higher end of the input voltage range. 

## **APPLICATIONS INFORMATION** 

The typical LTM4609 application circuit is shown in Figure 18. External component selection is primarily determined by the maximum load current and output voltage. Refer to Table 3 for specific external capacitor requirements for a particular application. 

## **Output Voltage Programming** 

The PWM controller has an internal 0.8V reference voltage. As shown in the Figure 1 (Block Diagram), a 100k internal feedback resistor connects VOUT and VFB pins together. Adding a resistor RFB from the VFB pin to the SGND pin programs the output voltage: 

**==> picture [122 x 31] intentionally omitted <==**

## **Operation Frequency Selection** 

The LTM4609 uses current mode control architecture at constant switching frequency, which is determined by the internal oscillator’s capacitor. This internal capacitor is charged by a fixed current plus an additional current that is proportional to the voltage applied to the PLLFLTR pin. The PLLFLTR pin can be grounded to lower the frequency to 200kHz or tied to 2.4V to yield approximately 400kHz. When PLLFLTR is left open, the PLLFLTR pin goes low, forcing the oscillator to its minimum frequency. 

A graph for the voltage applied to the PLLFLTR pin vs frequency is given in Figure 2. As the operating frequency increases, the gate charge losses will be higher, thus the efficiency is lower. The maximum switching frequency is approximately 400kHz. 

**Table 1. RFB Resistor (0.5%) vs Output Voltage** 

|VOUT|0.8V|1.5V|2.5V|3.3V|5V|6V|8V|9V|
|---|---|---|---|---|---|---|---|---|
|RFB|Open|115k|47.5k|32.4k|19.1k|15.4k|11k|9.76k|
|VOUT|10V|12V|15V|16V|20V|24V|30V|34V|
|RFB|8.66k|7.15k|5.62k|5.23k|4.12k|3.4k|2.74k|2.37k|



## **FREQUENCY SYNCHRONIZATION** 

The LTM4609 can also be synchronized to an external source via the PLLIN pin instead of adjusting the voltage on the PLLFLTR pin directly. The power module has a 

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LTM4609 

## **APPLICATIONS INFORMATION** 

phase-locked loop comprised of an internal voltage controlled oscillator and a phase detector. This allows turning on the internal top MOSFET for locking to the rising edge of the external clock. A pulse detection circuit is used to detect a clock on the PLLIN pin to turn on the phase-locked loop. The input pulse width of the clock has to be at least 400ns, and 2V in amplitude. The synchronized frequency ranges from 200kHz to 400kHz, corresponding to a DC voltage input from 0V to 2.4V at PLLFLTR. During the start-up of the regulator, the phase-locked loop function is disabled. 

**==> picture [163 x 161] intentionally omitted <==**

**----- Start of picture text -----**<br>
450<br>400<br>350<br>300<br>250<br>200<br>150<br>100<br>50<br>0<br>0 0.5 1.0 1.5 2.0 2.5<br>PLLFLTR PIN VOLTAGE (V)<br>4609 F02<br>OPERATING FREQUENCY (kHz)<br>**----- End of picture text -----**<br>


**Figure 2. Frequency vs PLLFLTR Pin Voltage** 

## **Low Current Operation** 

To improve efficiency at low output current operation, LTM4609 provides three modes for both buck and boost operations by accepting a logic input on the FCB pin. Table 2 shows the different operation modes. 

**Table 2. Different Operating Modes (VINTVCC = 6V)** 

|**FCB PIN**|**BUCK**|**BOOST**|
|---|---|---|
|0V to 0.75V|Forced Continuous Mode|Forced Continuous Mode|
|0.85V to<br>VINTVCC– 1V|Skip-Cycle Mode|Burst Mode Operation|
|>5.3V|DCM with Constant Freq|DCM with Constant Freq|



When the FCB pin voltage is lower than 0.8V, the controller behaves as a continuous, PWM current mode synchronous switching regulator. When the FCB pin voltage is below VINTVCC – 1V, but greater than 0.85V, where VINTVCC is 6V, the controller enters Burst Mode operation in boost operation or enters skip-cycle mode in buck operation. During boost operation, Burst Mode operation is activated 

if the load current is lower than the preset minimum output current level. The MOSFETs will turn on for several cycles, followed by a variable “sleep” interval depending upon the load current. During buck operation, skip-cycle mode sets a minimum positive inductor current level. In this mode, some cycles will be skipped when the output load current drops below 1% of the maximum designed load in order to maintain the output voltage. 

When the FCB pin voltage is tied to the INTVCC pin, the controller enters constant frequency discontinuous current mode (DCM). For boost operation, if the output voltage is high enough, the controller can enter the continuous current buck mode for one cycle to discharge inductor current. In the following cycle, the controller will resume DCM boost operation. For buck operation, constant frequency discontinuous current mode is turned on if the preset minimum negative inductor current level is reached. At very light loads, this constant frequency operation is not as efficient as Burst Mode operation or skip-cycle, but does provide low noise, constant frequency operation. 

## **Input Capacitors** 

In boost mode, since the input current is continuous, only minimum input capacitors are required. However, the input current is discontinuous in buck mode. So the selection of input capacitor CIN is driven by the need of filtering the input square wave current. 

For a buck converter, the switching duty-cycle can be estimated as: 

**==> picture [46 x 32] intentionally omitted <==**

Without considering the inductor current ripple, the RMS current of the input capacitor can be estimated as: 

**==> picture [164 x 33] intentionally omitted <==**

In the above equation, η is the estimated efficiency of the power module. CIN can be a switcher-rated electrolytic aluminum capacitor, OS-CON capacitor or high volume ceramic capacitors. Note the capacitor ripple current ratings are often based on temperature and hours of life. This 

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LTM4609 

## **APPLICATIONS INFORMATION** 

makes it advisable to properly derate the input capacitor, or choose a capacitor rated at a higher temperature than required. Always contact the capacitor manufacturer for derating requirements. 

## **Output Capacitors** 

In boost mode, the discontinuous current shifts from the input to the output, so the output capacitor COUT must be capable of reducing the output voltage ripple. 

For boost and buck modes, the steady ripple due to charging and discharging the bulk capacitance is given by: 

**==> picture [220 x 91] intentionally omitted <==**

The steady ripple due to the voltage drop across the ESR (effective series resistance) is given by: 

**==> picture [130 x 44] intentionally omitted <==**

The LTM4609 is designed for low output voltage ripple. The bulk output capacitors defined as COUT are chosen with low enough ESR to meet the output voltage ripple and transient requirements. COUT can be the low ESR tantalum capacitor, the low ESR polymer capacitor or the ceramic capacitor. Multiple capacitors can be placed in parallel to meet the ESR and RMS current handling requirements. The typical capacitance is 300µF. Additional output filtering may be required by the system designer, if further reduction of output ripple or dynamic transient spike is required. Table 3 shows a matrix of different output voltages and output capacitors to minimize the voltage droop and overshoot at a current transient. 

## **Inductor Selection** 

The inductor is chiefly decided by the required ripple current and the operating frequency. The inductor current ripple Δ IL is typically set to 20% to 40% of the maximum 

inductor current. In the inductor design, the worst cases in continuous mode are considered as follows: 

**==> picture [227 x 96] intentionally omitted <==**

where: 

ƒ is operating frequency, Hz 

**==> picture [224 x 12] intentionally omitted <==**

**==> picture [195 x 14] intentionally omitted <==**

**==> picture [181 x 14] intentionally omitted <==**

**==> picture [124 x 12] intentionally omitted <==**

IOUT(MAX) is maximum output load current, A 

The inductor should have low DC resistance to reduce the I[2] R losses, and must be able to handle the peak inductor current without saturation. To minimize radiated noise, use a toroid, pot core or shielded bobbin inductor. Please refer to Table 3 for the recommended inductors for different cases. 

## **RSENSE Selection and Maximum Output Current** 

RSENSE is chosen based on the required inductor current. Since the maximum inductor valley current at buck mode is much lower than the inductor peak current at boost mode, different sensing resistors are suggested to use in buck and boost modes. 

The current comparator threshold sets the peak of the inductor current in boost mode and the maximum inductor valley current in buck mode. In boost mode, the allowed maximum average load current is: 

**==> picture [187 x 30] intentionally omitted <==**

where Δ IL is peak-to-peak inductor ripple current. 

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LTM4609 

## **APPLICATIONS INFORMATION** 

In buck mode, the allowed maximum average load current is: 

**==> picture [150 x 32] intentionally omitted <==**

The maximum current sensing RSENSE value for the boost mode is: 

**==> picture [178 x 57] intentionally omitted <==**

The maximum current sensing RSENSE value for the buck mode is: 

**==> picture [213 x 34] intentionally omitted <==**

A 20% to 30% margin on the calculated sensing resistor is usually recommended. Please refer to Table 3 for the recommended sensing resistors for different applications. 

## **Soft-Start** 

The SS pin provides a means to soft-start the regulator. A capacitor on this pin will program the ramp rate of the output voltage. A 1.7µA current source will charge up the external soft-start capacitor. This will control the ramp of the internal reference and the output voltage. The total soft-start time can be calculated as: 

**==> picture [118 x 31] intentionally omitted <==**

When the RUN pin falls below 1.6V, then the soft-start pin is reset to allow for proper soft-start control when the regulator is enabled again. Current foldback and force continuous mode are disabled during the soft-start process. Do not apply more than 6V to the SS pin. 

## **Run Enable** 

The RUN pin is used to enable the power module. The pin can be driven with a logic input, not to exceed 6V. 

The RUN pin can also be used as an undervoltage lockout (UVLO) function by connecting a resistor from the input supply to the RUN pin. The equation: 

**==> picture [120 x 28] intentionally omitted <==**

## **Power Good** 

The PGOOD pin is an open drain pin that can be used to monitor valid output voltage regulation. This pin monitors a ±7.5% window around the regulation point. 

## **COMP Pin** 

This pin is the external compensation pin. The module has already been internally compensated for most output voltages. A spice model is available for other control loop optimization. 

## **Fault Conditions: Current Limit and Overcurrent Foldback** 

LTM4609 has a current mode controller, which inherently limits the cycle-by-cycle inductor current not only in steady state operation, but also in transient. Refer to Table 3. 

To further limit current in the event of an overload condition, the LTM4609 provides foldback current limiting. If the output voltage falls by more than 70%, then the maximum output current is progressively lowered to about 30% of its full current limit value for boost mode and about 40% for buck mode. 

## **Standby Mode (STBYMD)** 

The standby mode (STBYMD) pin provides several choices for start-up and standby operational modes. If the pin is pulled to ground, the SS pin is internally pulled to ground, preventing start-up and thereby providing a 

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LTM4609 

## **APPLICATIONS INFORMATION** 

single control pin for turning off the controller. If the pin is left open or decoupled with a capacitor to ground, the SS pin is internally provided with a starting current, permitting external control for turning on the controller. If the pin is connected to a voltage greater than 1.25V, the internal regulator (INTVCC) will be on even when the controller is shut down (RUN pin voltage <1.6V). In this mode, the onboard 6V output linear regulator can provide power to keep-alive functions such as a keyboard controller. 

## **INTVCC and EXTVCC** 

An internal P-channel low dropout regulator produces 6V at the INTVCC pin from the VIN supply pin. INTVCC powers the control chip and internal circuitry within the module. 

The LTM4609 also provides the external supply voltage pin EXTVCC. When the voltage applied to EXTVCC rises above 5.7V, the internal regulator is turned off and an internal switch connects the EXTVCC pin to the INTVCC pin thereby supplying internal power. The switch remains closed as long as the voltage applied to EXTVCC remains above 5.4V. This allows the MOSFET driver and control power to be derived from the output when (5.7V < VOUT < 7V) and from the internal regulator when the output is out of regulation (start-up, short-circuit). If more current is required through the EXTVCC switch than is specified, an external Schottky diode can be interposed between the EXTVCC and INTVCC pins. Ensure that EXTVCC ≤ VIN. 

The following list summarizes the three possible connections for EXTVCC: 

1. EXTVCC left open (or grounded). This will cause INTVCC to be powered from the internal 6V regulator at the cost of a small efficiency penalty. 

2. EXTVCC connected directly to VOUT (5.7V < VOUT < 7V). This is the normal connection for a 6V regulator and provides the highest efficiency. 

3. EXTVCC connected to an external supply. If an external supply is available in the 5.5V to 7V range, it may be used to power EXTVCC provided it is compatible with the MOSFET gate drive requirements. 

## **Thermal Considerations and Output Current Derating** 

In different applications, LTM4609 operates in a variety of thermal environments. The maximum output current is limited by the environmental thermal condition. Sufficient cooling should be provided to ensure reliable operation. When the cooling is limited, proper output current derating is necessary, considering ambient temperature, airflow, input/output condition, and the need for increased reliability. 

The power loss curves in Figure 5 and Figure 6 can be used in coordination with the load current derating curves in Figure 7 to Figure 14 for calculating an approximate θ JA for the module. Column designation delineates between no heat sink, and a BGA heat sink. Each of the load current derating curves will lower the maximum load current as a function of the increased ambient temperature to keep the maximum junction temperature of the power module at 115°C allowing a safe margin for the maximum operating temperature below 125°C. Each of the derating curves and the power loss curve that corresponds to the correct output voltage can be used to solve for the approximate θ JA of the condition. 

## **DESIGN EXAMPLES** 

## **Buck Mode Operation** 

As a design example, use input voltage VIN = 12V to 36V, VOUT = 12V and ƒ = 400kHz. 

Set the PLLFLTR pin at 2.4V or more for 400kHz frequency and connect FCB to ground for continuous current mode operation. If a divider is used to set the frequency as shown in Figure 16, the bottom resistor R3 is recommended not to exceed 1k. 

To set the output voltage at 12V, the resistor RFB from VFB pin to ground should be chosen as: 

**==> picture [130 x 31] intentionally omitted <==**

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LTM4609 

## **APPLICATIONS INFORMATION** 

To choose a proper inductor, we need to know the current ripple at different input voltages. The inductor should be chosen by considering the worst case in the practical operating region. If the maximum output power P is 120W at buck mode, we can get the current ripple ratio of the current ripple Δ IL to the maximum inductor current IL as follows: 

**==> picture [129 x 35] intentionally omitted <==**

Figure 3 shows the current ripple ratio at different input voltages based on the inductor values: 2.5µH, 3.3µH, 4.7µH and 6µH. If we need about 40% ripple current ratio at all inputs, the 4.7µH inductor can be selected. 

At buck mode, sensing resistor selection is based on the maximum output current and the allowed maximum sensing threshold 130mV. 

**==> picture [138 x 31] intentionally omitted <==**

Consider the safety margin about 30%, we can choose the sensing resistor as 9mΩ. 

**==> picture [161 x 160] intentionally omitted <==**

**----- Start of picture text -----**<br>
0.8<br>VOUT = 12V<br>ƒ = 400kHz 2.5µH<br>0.6<br>3.3µH<br>0.4 4.7µH<br>6µH<br>0.2<br>0<br>12 18 24 30 36<br>INPUT VOLTAGE VIN (V)<br>4609 F03<br>CURRENT RIPPLE RATIO<br>**----- End of picture text -----**<br>


For the input capacitor, use a low ESR sized capacitor to handle the maximum RMS current. Input capacitors are required to be placed adjacent to the module. In Figure 16, the 10µF ceramic input capacitors are selected for their ability to handle the large RMS current into the converter. The 100µF bulk capacitor is only needed if the input source impedance is compromised by long inductive leads or traces. 

For the output capacitor, the output voltage ripple and transient requirements require low ESR capacitors. If assuming that the ESR dominates the output ripple, the output ripple is as follows: 

**==> picture [107 x 16] intentionally omitted <==**

If a total low ESR of about 5mΩ is chosen for output capacitors, the maximum output ripple of 21.5mV occurs at the input voltage of 36V with the current ripple at 4.3A. 

## **Boost Mode Operation** 

For boost mode operation, use input voltage VIN = 5V to 12V, VOUT = 12V and ƒ = 400kHz. 

Set the PLLFLTR pin and RFB as in buck mode. 

If the maximum output power P is 50W at boost mode and the module efficiency η is about 90%, we can get the current ripple ratio of the current ripple Δ IL to the maximum inductor current IL as follows: 

**==> picture [126 x 36] intentionally omitted <==**

Figure 4 shows the current ripple ratio at different input voltages based on the inductor values: 1.5µH, 2.5µH, 3.3µH and 4.7µH. If we need 30% ripple current ratio at all inputs, the 3.3µH inductor can be selected. 

**Figure 3. Current Ripple Ratio at Different Inputs for Buck Mode** 

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LTM4609 

## **APPLICATIONS INFORMATION** 

**==> picture [163 x 161] intentionally omitted <==**

**----- Start of picture text -----**<br>
0.8<br>VOUT = 12V<br>ƒ = 400kHz<br>1.5µH<br>0.6<br>0.4 2.5µH<br>3.3µH<br>4.7µH<br>0.2<br>0<br>5 6 7 8 9 10 11 12<br>INPUT VOLTAGE VIN (V)<br>4609 F04<br>CURRENT RIPPLE RATIO<br>**----- End of picture text -----**<br>


**Figure 4. Current Ripple Ratio at Different Inputs for Boost Mode** 

At boost mode, sensing resistor selection is based on the maximum input current and the allowed maximum sensing threshold 160mV. 

**==> picture [146 x 49] intentionally omitted <==**

Consider the safety margin about 30%, we can choose the sensing resistor as 8mΩ. 

For the input capacitor, only minimum capacitors are needed to handle the maximum RMS current, since it is a continuous input current at boost mode. A 100µF capacitor is only needed if the input source impedance is compromised by long inductive leads or traces. 

Since the output capacitors at boost mode need to filter the square wave current, more capacitors are expected to achieve the same output ripples as the buck mode. If 

assuming that the ESR dominates the output ripple, the output ripple is as follows: 

**==> picture [125 x 16] intentionally omitted <==**

If a total low ESR about 5mΩ is chosen for output capacitors, the maximum output ripple of 70mV occurs at the input voltage of 5V with the peak inductor current at 14A. 

An RC snubber is recommended on SW1 to obtain low switching noise, as shown in Figure 17. 

## **Wide Input Mode Operation** 

- If a wide input range is required from 5V to 36V, the mod ule will work in different operation modes. If input voltage VIN = 5V to 36V, VOUT = 12V and ƒ = 400kHz, the design needs to consider the worst case in buck or boost mode design. Therefore, the maximum output power is limited to 60W. The sensing resistor is chosen at 8mΩ, the input capacitor is the same as the buck mode design and the output capacitor uses the boost mode design. Since the maximum output ripple normally occurs at boost mode in the wide input mode design, more inductor ripple current, up to 150% of the inductor current, is allowed at buck mode to meet the ripple design requirement. Thus, a 3.3µH inductor is chosen at the wide input mode. The maximum output ripple voltage is still 70mV if the total ESR is about 5mΩ. 

Additionally, the current limit may become very high when the module runs at buck mode due to the low sensing resistor used in the wide input mode operation. 

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LTM4609 

## **APPLICATIONS INFORMATION** 

**Table 3. Typical Components (ƒ = 400kHz)** 

|**COUT1 VENDORS**|**PART NUMBER**|**COUT2 VENDORS**|**PART NUMBER**|
|---|---|---|---|
|TDK|C4532X7R1E226M (22µF, 25V)|Sanyo|16SVP180MX (180µF, 16V), 20SVP150MX (150µF, 20V)|
|**INDUCTOR VENDORS**|**PART NUMBER**|**RSENSE VENDORS**|**PART NUMBER**|
|Toko|FDA1254|Vishay|Power Metal Strip Resistors WSL1206-18|
|Sumida|CDEP134, CDEP145, CDEP147|Panasonic|Thick Film Chip Resistors ERJ12|



|**VIN**<br>**(V)**|**VOUT**<br>**(V)**|**RSENSE**<br>**(0.5W RATING)**|**Inductor**<br>**(µH)**|**CIN**<br>**(CERAMIC)**|**CIN**<br>**(BULK)**|**COUT1**<br>**(CERAMIC)**|**COUT2**<br>**(BULK)**|**IOUT(MAX)* **<br>**(A)**|
|---|---|---|---|---|---|---|---|---|
|5|10|16mW ×2 0.5W|2.2|None|150µF 35V|22µF ×4 25V|180µF ×2 16V|4|
|15|10|18mW ×2 0.5W|2.2|10µF ×2 25V|150µF 35V|22µF ×2 25V|180µF ×2 16V|11|
|20|10|20mW ×2 0.5W|3.3|10µF ×2 25V|150µF 35V|22µF ×2 25V|180µF ×2 16V|10|
|24|10|18mΩ ×2 0.5W|3.3|10µF ×2 25V|150µF 35V|22µF ×2 25V|180µF ×2 16V|10|
|32|10|22mΩ ×2 0.5W|4.7|10µF ×2 50V|150µF 35V|22µF ×2 25V|180µF ×2 16V|9|
|36|10|22mΩ ×2 0.5W|4.7|10µF ×2 50V|150µF 50V|22µF ×2 25V|180µF ×2 16V|9|
|6|12|14mΩ ×2 0.5W|2.2|None|150µF 35V|22µF ×4 25V|180µF ×2 16V|4|
|16|12|16mW ×2 0.5W|2.2|10µF ×2 25V|150µF 35V|22µF ×2 25V|180µF ×2 16V|11|
|20|12|18mW ×2 0.5W|3.3|10µF ×2 25V|150µF 35V|22µF ×2 25V|180µF ×2 16V|10|
|24|12|18mΩ ×2 0.5W|3.3|10µF ×2 25V|150µF 35V|22µF ×2 25V|180µF ×2 16V|9|
|32|12|22mΩ ×2 0.5W|4.7|10µF ×2 50V|150µF 35V|22µF ×2 25V|180µF ×2 16V|9|
|36|12|22mΩ ×2 0.5W|4.7|10µF ×2 50V|150µF 50V|22µF ×2 25V|180µF ×2 16V|9|
|5|16|18mW ×2 0.5W|3.3|None|150µF 35V|22µF ×4 25V|150µF ×2 20V|2.5|
|8|16|16mW ×2 0.5W|3.3|None|150µF 35V|22µF ×4 25V|150µF ×2 20V|4|
|12|16|14mW ×20.5W|2.2|None|150µF 35V|22µF ×4 25V|150µF ×2 20V|8|
|20|16|20mW ×2 0.5W|2.2|10µF ×2 25V|150µF 35V|22µF ×2 25V|150µF ×2 20V|10|
|24|16|20mΩ ×2 0.5W|3.3|10µF ×2 25V|150µF 35V|22µF ×2 25V|150µF ×2 20V|10|
|32|16|22mΩ ×20.5W|4.7|10µF ×2 50V|150µF 35V|22µF ×2 25V|150µF ×2 20V|9|
|36|16|22mΩ ×2 0.5W|6|10µF ×2 50V|150µF 50V|22µF ×2 25V|150µF ×2 20V|9|
|5|20|18mΩ ×2 0.5W|3.3|NONE|150µF 50V|22µF ×4 25V|150µF ×2 50V|2|
|10|20|18mΩ ×2 0.5W|3.3|NONE|150µF 50V|22µF ×4 25V|150µF ×2 50V|5|
|32|20|12mΩ ×1 0.5W|6|10µF ×2 50V|150µF 50V|22µF ×2 25V|150µF ×2 50V|9|
|36|20|13mΩ ×1 0.5W|8|10µF ×2 50V|150µF 50V|22µF ×2 25V|150µF ×2 50V|8|
|5|24|16mΩ ×2 0.5W|3.3|NONE|150µF 50V|22µF ×4 25V|150µF ×2 50V|1.5|
|12|24|18mΩ ×2 0.5W|4.7|NONE|150µF 50V|22µF ×4 25V|150µF ×2 50V|5|
|32|24|14mΩ ×1 0.5W|4.7|10µF ×2 50V|150µF 50V|22µF ×2 25V|150µF ×2 50V|8|
|36|24|13mΩ ×1 0.5W|7|10µF ×2 50V|150µF 50V|22µF ×2 25V|150µF ×2 50V|8|



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LTM4609 

## **APPLICATIONS INFORMATION** 

**Table 3. Typical Components (ƒ = 400kHz) Continued** 

|**VIN**<br>**(V)**|**VOUT**<br>**(V)**|**RSENSE**<br>**(0.5W RATING)**|**Inductor**<br>**(µH)**|**CIN**<br>**(CERAMIC)**|**CIN**<br>**(BULK)**|**COUT1**<br>**(CERAMIC)**|**COUT2**<br>**(BULK)**|**IOUT(MAX)* **<br>**(A)**|
|---|---|---|---|---|---|---|---|---|
|5|30|16mΩ ×2 0.5W|3.3|NONE|150µF 50V|22µF ×4 50V|150µF ×2 50V|1.3|
|12|30|14mΩ ×2 0.5W|4.7|NONE|150µF 50V|22µF ×4 50V|150µF ×2 50V|3|
|32|30|12mΩ ×1 0.5W|2.5|10µF ×2 50V|150µF 50V|22µF ×2 50V|150µF ×2 50V|8|
|36|30|13mΩ ×1 0.5W|4.7|10µF ×2 50V|150µF 50V|22µF ×2 50V|150µF ×2 50V|8|
|5|34|18mΩ ×2 0.5W|3.3|NONE|150µF 50V|22µF ×4 50V|150µF ×2 50V|1|
|12|34|16mΩ ×2 0.5W|4.7|NONE|150µF 50V|22µF ×4 50V|150µF ×2 50V|3|
|24|34|12mΩ ×1 0.5W|5.6|NONE|150µF 50V|22µF ×4 50V|150µF ×2 50V|5|
|36|34|12mΩ ×1 0.5W|2.5|10µF ×2 50V|150µF 50V|22µF ×2 50V|150µF ×2 50V|8|



|**INDUCTOR MANUFACTURER**|**WEBSITE**|
|---|---|
|Sumida|www.sumida.com|
|Toko|www.toko.com|
|||
|**SENSING RESISTOR MANUFACTURER**|**WEBSITE**|
|Panasonic|www.panasonic.com/industrial/components|
|KOA|www.koaspeer.com|
|Vishay|www.vishay.com|



*Maximum load current is based on the Analog Devices demo board DC1198A at room temperature with natural convection. Poor board layout design may decrease the maximum load current. 

## **APPLICATIONS INFORMATION** 

## **(Power Loss includes all external components)** 

**==> picture [159 x 166] intentionally omitted <==**

**----- Start of picture text -----**<br>
7<br>6<br>5<br>4<br>3<br>2<br>1<br>5VIN T O  16VOUT<br>5VIN TO 30VOUT<br>0<br>0 1 2 3<br>LOAD CURRENT (A)<br>4609 F05<br>POWER LOSS (W)<br>**----- End of picture text -----**<br>


**Figure 5. Boost Mode Operation** 

**==> picture [159 x 166] intentionally omitted <==**

**----- Start of picture text -----**<br>
7<br>32VIN TO 12VOUT<br>6 36VIN TO 20VOUT<br>5<br>4<br>3<br>2<br>1<br>0<br>0 1 2 3 4 5 6 7 8 9<br>LOAD CURRENT (A)<br>4609 F06<br>POWER LOSS (W)<br>**----- End of picture text -----**<br>


**Figure 6. Buck Mode Operation** 

Rev. G 

17 

For more information www.analog.com 

LTM4609 

## **APPLICATIONS INFORMATION** 

**==> picture [162 x 607] intentionally omitted <==**

**----- Start of picture text -----**<br>
3.0<br>2.5<br>2.0<br>1.5<br>1.0<br>0.5 5V IN  TO 16V OUT  WITH 0LFM<br>5VIN TO 16VOUT WITH 200LFM<br>5VIN TO 16VOUT WITH 400LFM<br>0<br>25 35 45 55 65 75 85 95 105 115<br>AMBIENT TEMPERATURE (°C)<br>4609 F07<br>Figure 7. 5VIN to 16VOUT without Heat SinkIN to 16VOUT without Heat Sink to 16VOUT without Heat SinkOUT without Heat Sink without Heat Sink<br>1.50<br>1.25<br>1.00<br>0.75<br>0.50<br>0.25 5VIN TO 30VOUT WITH 0LFM<br>5VIN TO 30VOUT WITH 200LFM<br>5VIN TO 30VOUT WITH 400LFM<br>0<br>25 35 45 55 65 75 85 95 105<br>AMBIENT TEMPERATURE (°C)<br>4609 F09<br>Figure 9. 5VIN to 30VOUT without Heat SinkIN to 30VOUT without Heat Sink to 30VOUT without Heat SinkOUT without Heat Sink without Heat Sink<br>10<br>9<br>8<br>7<br>6<br>5<br>4<br>3<br>2<br>1<br>0<br>25 35 45 55 65 75 85 95<br>AMBIENT TEMPERATURE (°C)<br>32VIN TO 12VOUT WITH 0LFM<br>32VIN TO 12VOUT WITH 200LFM<br>32VIN TO 12VOUT WITH 400LFM 4609 F11<br>MAXIMUM LOAD CURRENT (A)<br>MAXIMUM LOAD CURRENT (A)<br>MAXIMUM LOAD CURRENT (A)<br>**----- End of picture text -----**<br>


**Figure 7. 5VIN to 16VOUT without Heat SinkIN to 16VOUT without Heat Sink to 16VOUT without Heat SinkOUT without Heat Sink without Heat Sink** 

**Figure 9. 5VIN to 30VOUT without Heat SinkIN to 30VOUT without Heat Sink to 30VOUT without Heat SinkOUT without Heat Sink without Heat Sink** 

**Figure 11. 32VIN to 12VOUT without Heat Sink** 

**==> picture [163 x 388] intentionally omitted <==**

**----- Start of picture text -----**<br>
3.0<br>2.5<br>2.0<br>1.5<br>1.0<br>0.5<br>0<br>25 45 65 85 105 125<br>AMBIENT TEMPERATURE (°C)<br>4609 F08<br>5VIN TO 16VOUT WITH 0LFM<br>5VIN TO 16VOUT  WITH 200LFM<br>5VIN TO 16VOUT  WITH 400LFM<br>Figure 8. 5VIN to 16VOUT with Heat Sink<br>1.50<br>1.25<br>1.00<br>0.75<br>0.50<br>0.25 5VIN TO 30VOUT WITH 0LFM<br>5VIN TO 30VOUT WITH 200LFM<br>5VIN TO 30VOUT WITH 400LFM<br>0<br>25 35 45 55 65 75 85 95 105<br>AMBIENT TEMPERATURE (°C)<br>4609 F10<br>MAXIMUM LOAD CURRENT (A)<br>MAXIMUM LOAD CURRENT (A)<br>**----- End of picture text -----**<br>


**Figure 10. 5VIN to 30VOUT with Heat Sink** 

**==> picture [157 x 187] intentionally omitted <==**

**----- Start of picture text -----**<br>
10<br>9<br>8<br>7<br>6<br>5<br>4<br>3<br>2<br>1<br>0<br>25 35 45 55 65 75 85 95<br>AMBIENT TEMPERATURE (°C)<br>32VIN TO 12VOUT WITH 0LFM<br>32VIN TO 12VOUT WITH 200LFM<br>32VIN TO 12VOUT WITH 400LFM 4609 F12<br>MAXIMUM LOAD CURRENT (A)<br>**----- End of picture text -----**<br>


**Figure 12. 32VIN to 12VOUT with Heat Sink** 

Rev. G 

18 

For more information www.analog.com 

LTM4609 

## **APPLICATIONS INFORMATION** 

**==> picture [162 x 188] intentionally omitted <==**

**----- Start of picture text -----**<br>
8<br>7<br>6<br>5<br>4<br>3<br>2<br>1<br>0<br>25 35 45 55 65 75 85 95 105<br>AMBIENT TEMPERATURE (°C)<br>36VIN TO 20VOUT WITH 0LFM 4609 F13<br>36VIN TO 20VOUT WITH 200LFM<br>36VIN TO 20VOUT WITH 400LFM<br>MAXIMUM LOAD CURRENT (A)<br>**----- End of picture text -----**<br>


**Figure 13. 36VIN to 20VOUT without Heat Sink** 

**==> picture [162 x 188] intentionally omitted <==**

**----- Start of picture text -----**<br>
8<br>7<br>6<br>5<br>4<br>3<br>2<br>1<br>0<br>25 35 45 55 65 75 85 95 105<br>AMBIENT TEMPERATURE (°C)<br>36VIN TO 20VOUT WITH 0LFM 4609 F14<br>36VIN TO 20VOUT WITH 200LFM<br>36VIN TO 20VOUT WITH 400LFM<br>MAXIMUM LOAD CURRENT (A)<br>**----- End of picture text -----**<br>


**Figure 14. 36VIN to 20VOUT with Heat Sink** 

**Table 4. Boost Mode** 

|**Table 4. Boost Mode**||||||
|---|---|---|---|---|---|
|**DERATING CURVE**|**VOUT (V)**|**POWER LOSS CURVE**|**AIR FLOW (LFM)**|**HEAT SINK**|θ**JA (°C/W)***|
|Figure 7, Figure 9|16, 30|Figure 5|0|None|11.4|
|Figure 7, Figure 9|16, 30|Figure 5|200|None|8.5|
|Figure 7, Figure 9|16, 30|Figure 5|400|None|7.5|
|Figure 8, Figure 10|16, 30|Figure 5|0|BGA Heat Sink|11.0|
|Figure 8, Figure 10|16, 30|Figure 5|200|BGA Heat Sink|7.9|
|Figure 8, Figure 10|16, 30|Figure 5|400|BGA Heat Sink|7.1|



**Table 5. Buck Mode** 

|**Table 5. Buck Mode**||||||||
|---|---|---|---|---|---|---|---|
|**DERATING CURVE**|**VOUT (V)**|**POWER LOSS CURVE**||**AIR FLOW (LFM)**|**HEAT SINK**||θ**JA (°C/W)***|
|Figure 11, Figure 13|12, 20|Figure 6||0|None||8.2|
|Figure 11, Figure 13|12, 20|Figure 6||200|None||5.9|
|Figure 11, Figure 13|12, 20|Figure 6||400|None||5.4|
|Figure 12, Figure 14|12, 20|Figure 6||0|BGA Heat Sink||7.5|
|Figure 12, Figure 14|12, 20|Figure 6||200|BGA Heat Sink||5.3|
|Figure 12, Figure 14|12, 20|Figure 6||400|BGA Heat Sink||4.8|
|||||||||
|**HEAT SINK MANUFACTURER**|||**PART NUMBER**|||**WEBSITE**||
|Aavid Thermalloy|||375424B00034G|||www.aavidthermalloy.com||
|Cool Innovations|||4-050503P to 4-050508P|||www.coolinnovations.com||



*The results of thermal resistance from junction to ambient θ JA are based on the demo board DC 1198A. Thus, the maximum temperature on board is treated as the junction temperature (which is in the µModule regulator for most cases) and the power losses from all components are counted for calculations. It has to be mentioned that poor board design may increase the θ JA. 

Rev. G 

19 

For more information www.analog.com 

LTM4609 

## **APPLICATIONS INFORMATION** 

## **Safety Considerations** 

The LTM4609 modules do not provide isolation from VIN to VOUT. There is no internal fuse. If required, a slow blow fuse with a rating twice the maximum input current needs to be provided to protect each unit from catastrophic failure. 

## **Layout Checklist/Example** 

The high integration of LTM4609 makes the PCB board layout very simple and easy. However, to optimize its electrical and thermal performance, some layout considerations are still necessary. 

- Use large PCB copper areas for high current path, including VIN, RSENSE, SW1, SW2, PGND and VOUT. It helps to minimize the PCB conduction loss and thermal stress. 

- Route SENSE[–] and SENSE[+] leads together with minimum PC trace spacing. Avoid sense lines passing through noisy areas, such as switch nodes. 

- Place a dedicated power ground layer underneath the unit. 

- To minimize the via conduction loss and reduce module thermal stress, use multiple vias for interconnection between the top layer and other power layers 

- Do not put vias directly on pads, unless the vias are capped. 

- Use a separated SGND ground copper area for components connected to signal pins. Connect the SGND to PGND underneath the unit. 

Figure 15. gives a good example of the recommended layout. 

- Place high frequency input and output ceramic capacitors next to the VIN, PGND and VOUT pins to minimize high frequency noise. 

**==> picture [238 x 234] intentionally omitted <==**

**----- Start of picture text -----**<br>
SW1 SW2 VIN<br>L1<br>CIN<br>VOUT RSENSE<br>COUT<br>+ – SGND<br>PGND PGND<br>RSENSE 4609 F15<br>KELVIN CONNECTIONS TO RSENSE<br>**----- End of picture text -----**<br>


**Figure 15. Recommended PCB Layout (LGA Shown, for BGA Use Circle Pads)** 

Rev. G 

20 

For more information www.analog.com 

LTM4609 

## **TYPICAL APPLICATIONS** 

**==> picture [298 x 164] intentionally omitted <==**

**----- Start of picture text -----**<br>
VIN<br>12V TO 36V 10µF50V×2  ON/OFF RUNPGOOD VIN PLLIN VFCBOUT + 100µF V12V10AOUT<br>L1 25V<br>COMP LTM4609 4.7µH<br>INTVCC SW1<br>R1<br>1.5k PLLFLTR SW2<br>EXTVCC RSENSE<br>R3 C3 STBYMD SENSE [+]<br>1k<br>0.1µF R2<br>9mΩ<br>SS SENSE [–]<br>SGND PGND VFB<br>RFB<br>7.15k<br>4609 F16<br>**----- End of picture text -----**<br>


**Figure 16. Buck Mode Operation with 12V to 36V Input** 

**==> picture [379 x 181] intentionally omitted <==**

**----- Start of picture text -----**<br>
VIN<br>5V TO 12V<br>4.7µF VOUT<br>35V PGOOD VIN PLLIN VOUT 12V<br>ON/OFF RUN FCB 22µF + 330µF 4A<br>25V 25V<br>COMP LTM4609 ×2<br>2Ω [2200pF]<br>INTVCC SW1<br>R1<br>1.5k PLLFLTR SW2<br>L1<br>OPTIONAL<br>R3 3.3µH FOR LOW<br>1k EXTVCC RSENSE SWITCHING NOISE<br>C3 STBYMD SENSE [+]<br>0.1µF R2<br>8mΩ<br>SS SENSE [–]<br>SGND PGND VFB<br>RFB<br>7.15k<br>4609 F17<br>**----- End of picture text -----**<br>


**Figure 17. Boost Mode Operation with 5V to 12V Input with Low Switching Noise (Optional)** 

Rev. G 

21 

For more information www.analog.com 

LTM4609 

## **TYPICAL APPLICATIONS** 

**==> picture [388 x 180] intentionally omitted <==**

**----- Start of picture text -----**<br>
VIN<br>5V TO 36V 10µF50V×2 ON/OFF RUNPGOOD VIN PLLIN VFCBOUT 2200pF 22µF25V + 330µF25V V12V4AOUT<br>COMP LTM4609 ×4<br>INTVCC SW1<br>1.5kR1 PLLFLTR L1 2Ω<br>3.3µH<br>SW2<br>R3<br>1k EXTVCC RSENSE<br>C3 STBYMD SENSE [+]<br>0.1µF R2<br>8mΩ<br>SS SENSE [–]<br>SGND PGND VFB<br>RFB<br>7.15k<br>4609 F18<br>**----- End of picture text -----**<br>


**Figure 18. Wide Input Mode with 5V to 36V Input, 12V at 4A Output** 

**==> picture [294 x 164] intentionally omitted <==**

**----- Start of picture text -----**<br>
VIN<br>8V TO 36V<br>10µF VOUT<br>50V×2  ON/OFF RUNPGOOD VIN PLLIN VFCBOUT + 220µF 32V2A<br>L1 50V<br>COMP LTM4609 4.7µH<br>INTVCC SW1<br>R1<br>1.5k PLLFLTR SW2<br>EXTVCC RSENSE<br>R3 C3 STBYMD SENSE [+]<br>1k<br>0.1µF R2<br>9mΩ<br>SS SENSE [–]<br>SGND PGND VFB<br>RFB<br>2.55k<br>4609 F19<br>**----- End of picture text -----**<br>


**Figure 19. 32V at 2A Design** 

Rev. G 

22 

For more information www.analog.com 

LTM4609 

## **TYPICAL APPLICATIONS** 

**==> picture [522 x 361] intentionally omitted <==**

**----- Start of picture text -----**<br>
VIN<br>5V TO 36V<br>CLOCK SYNC 0° PHASE<br>10µF R5 VOUT<br>50V 100k PGOOD VIN PLLIN VOUT 12V<br>RUN FCB C2 + 330µF 8A<br>L1 22µF 25V<br>LTM4609 3.3µH 25V<br>COMP SW1 ×2<br>200Ω<br>INTVCC SW2<br>5.1V C1 LTC6908-1 5.1V PLLFLTR RSENSE<br>ZENER 0.1µF V [+] OUT1 EXTVCC SENSE [+]<br>STBYMD R2<br>R4 8mΩ<br>324k GND OUT2 SS SENSE [–]<br>C3<br>SET MOD 0.1µF<br>SGND PGND VFB<br>2-PHASE OSCILLATOR RFB*<br>3.57k<br>CLOCK SYNC 180° PHASE<br>10µF<br>50V PGOOD VIN PLLIN VOUT<br>+<br>FCB C4 330µF<br>L2 22µF 25V<br>RUN LTM4609 3.3µH 25V<br>COMP SW1 ×2<br>INTVCC SW2<br>PLLFLTR RSENSE<br>EXTVCC SENSE [+] *RFB IS SELECTED USING<br>STBYMD R3 100k<br>SS SENSE [–] 8mΩ VOUT = 0.8V N R FB+ R FB<br>WHERE N IS THE NUMBER<br>SGND PGND VFB OF PARALLELED MODULES.<br>4609 F20<br>**----- End of picture text -----**<br>


**Figure 20. Two-Phase Parallel, 12V at 8A Design** 

Rev. G 

23 

For more information www.analog.com 

LTM4609 

## **PACKAGE DESCRIPTION** 

**Table 6. Pin Assignment (Arranged by Pin Number)** 

|**PIN NAME**|**FUNCTION**|**PIN NAME**|**FUNCTION**|**PIN NAME**|**FUNCTION**|**PIN NAME**|**FUNCTION**|**PIN NAME**|**FUNCTION**|**PIN NAME**|**FUNCTION**|
|---|---|---|---|---|---|---|---|---|---|---|---|
|A1|PGND|C1|PGND|E1|VOUT|G1|VOUT|J1|SW1|L1|SW1|
|A2|PGND|C2|PGND|E2|VOUT|G2|VOUT|J2|SW1|L2|SW1|
|A3|PGND|C3|PGND|E3|PGND|G3|VOUT|J3|SW1|L3|SW1|
|A4|SENSE+|C4|PGND|E4|PGND|G4|VOUT|J4|SW1|L4|SW1|
|A5|SENSE–|C5|PGND|E5|PGND|G5|RSENSE|J5|RSENSE|L5|RSENSE|
|A6|SS|C6|PGND|E6|PGND|G6|RSENSE|J6|RSENSE|L6|RSENSE|
|A7|SGND|C7|PGND|E7|PGND|G7|RSENSE|J7|RSENSE|L7|SW2|
|A8|RUN|C8|PGND|E8|PGND|G8|RSENSE|J8|SW2|L8|SW2|
|A9|FCB|C9|PGND|E9|PGND|G9|RSENSE|J9|SW2|L9|SW2|
|A10|STBYMD|C10|PGND|E10|PGND|G10|RSENSE|J10|VIN|L10|VIN|
|A11|PGND|C11|PGND|E11|PGND|G11|RSENSE|J11|VIN|L11|VIN|
|A12|PGND|C12|PGND|E12|PGND|G12|RSENSE|J12|VIN|L12|VIN|
|B1|PGND|D1|PGND|F1|VOUT|H1|VOUT|K1|SW1|M1|SW1|
|B2|PGND|D2|PGND|F2|VOUT|H2|VOUT|K2|SW1|M2|SW1|
|B3|PGND|D3|PGND|F3|VOUT|H3|VOUT|K3|SW1|M3|SW1|
|B4|PGND|D4|PGND|F4|VOUT|H4|VOUT|K4|SW1|M4|SW1|
|B5|PGOOD|D5|PGND|F5|INTVCC|H5|RSENSE|K5|RSENSE|M5|RSENSE|
|B6|VFB|D6|PGND|F6|EXTVCC|H6|RSENSE|K6|RSENSE|M6|RSENSE|
|B7|COMP|D7|PGND|F7|–|H7|RSENSE|K7|SW2|M7|SW2|
|B8|PLLFLTR|D8|PGND|F8|–|H8|RSENSE|K8|SW2|M8|SW2|
|B9|PLLIN|D9|PGND|F9|–|H9|RSENSE|K9|SW2|M9|SW2|
|B10|PGND|D10|PGND|F10|RSENSE|H10|RSENSE|K10|VIN|M10|VIN|
|B11|PGND|D11|PGND|F11|RSENSE|H11|RSENSE|K11|VIN|M11|VIN|
|B12|PGND|D12|PGND|F12|RSENSE|H12|RSENSE|K12|VIN|M12|VIN|



Rev. G 

24 

For more information www.analog.com 

LTM4609 

## **PACKAGE DESCRIPTION** 

**==> picture [466 x 612] intentionally omitted <==**

**----- Start of picture text -----**<br>
7<br>SEE NOTES<br>C(0.22 x 45°) PAD 1<br>M L K J H G F E D C B A<br>1<br>LGA 141 1212 REV B<br>DETAIL A 2<br>3<br>4<br>5<br>e<br>6<br>G<br>7<br>8<br>PACKAGE BOTTOM VIEW<br>9<br>LTMXXXXXX µModule<br>10 PACKAGE IN TRAY LOADING ORIENTATION<br>PACKAGE ROW AND COLUMN LABELING MAY VARY  AMONG µModule PRODUCTS. REVIEW EACH PACKAGE  LAYOUT CAREFULLY<br>11 b<br>!<br>12 DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR  MARKED FEATURE<br>b e NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 2. ALL DIMENSIONS ARE IN MILLIMETERS 3        BALL DESIGNATION PER JESD MS-028 AND JEP95 4 5. PRIMARY DATUM -Z- IS SEATING PLANE 6. THE TOTAL NUMBER OF PADS: 141 7 PIN “A1” TRAY PIN 1 BEVEL<br>3 COMPONENT<br>F<br>SEE NOTES<br>NOTES<br>A<br>2.82mm) DETAIL B<br>× PACKAGE SIDE VIEW MAX 2.92 0.66 0.37 2.55 0.15 0.10 0.05<br>15mm<br>× H1 Y NOM 2.82 0.63 15.00 15.00 1.27 13.97 13.97 0.32 2.50<br>X<br>SUBSTRATE S DIMENSIONS<br>LGA Package<br>eee MIN 2.72 0.60 0.27 2.45<br>MOLD CAP H2 DETAIL B DETAIL A TOTAL NUMBER OF LGA PADS: 141<br>A b D E e F G H1 H2 aaa bbb eee<br>141-Lead (15mm (Reference LTC DWG # 05-08-1840 Rev B) SYMBOL<br>0.630 ±0.025 SQ. 143x<br>aaa  Z<br>0.0000<br>D X 6.9850 5.7150 4.4450 3.1750 1.9050 0.6350 0.6350 1.9050 3.1750 4.4450 5.7150 6.9850<br>Y<br>E<br>TOP VIEW<br>PACKAGE TOP VIEW<br>SUGGESTED PCB LAYOUT<br>4<br>PIN “A1” CORNER<br>Z<br>Zbbb<br>6.9850<br>5.7150<br>4.4450<br>3.1750<br>1.9050<br>0.6350<br>0.0000<br>0.6350<br>1.9050<br>3.1750<br>4.4450<br>5.7150<br>6.9850<br>aaa  Z<br>**----- End of picture text -----**<br>


Rev. G 

25 

For more information www.analog.com 

LTM4609 

## **PACKAGE DESCRIPTION** 

**==> picture [468 x 616] intentionally omitted <==**

**----- Start of picture text -----**<br>
6<br>SEE NOTES<br>PIN 1<br>M L K J H G F E D C B A<br>1<br>BGA 141 1218 REV D<br>2<br>3<br>4<br>5<br>e<br>6<br>G<br>7<br>8<br>PACKAGE BOTTOM VIEW<br>9<br>LTMXXXXXX µModule<br>10 PACKAGE IN TRAY LOADING ORIENTATION<br>PACKAGE ROW AND COLUMN LABELING MAY VARY  AMONG µModule PRODUCTS. REVIEW EACH PACKAGE  LAYOUT CAREFULLY<br>11 b<br>!<br>12 DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR  MARKED FEATURE<br>DETAIL A b e NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 2. ALL DIMENSIONS ARE IN MILLIMETERS 3        BALL DESIGNATION PER JESD MS-028 AND JEP95 4 5. PRIMARY DATUM -Z- IS SEATING PLANE 6 PIN “A1” TRAY PIN 1 BEVEL<br>3 COMPONENT<br>F<br>SEE NOTES<br>A<br>3.42mm) A2 NOTES BALL HT BALL DIMENSION PAD DIMENSION SUBSTRATE THK MOLD CAP HT<br>× DETAIL B<br>15mm  PACKAGE SIDE VIEW MAX 3.62 0.70 2.92 0.90 0.66 0.37 2.55 0.15 0.10 0.20 0.30 0.15<br>× Y<br>BGA Package A1 SUBSTRATE H1 MXZ MZ DIMENSIONS NOM 3.42 0.60 2.82 0.75 0.63 15.0 15.0 1.27 13.97 13.97 0.32 2.50<br>ddd eee<br>b1 MIN 3.22 0.50 2.72 0.60 0.60 0.27 2.45 TOTAL NUMBER OF BALLS: 141<br>ccc  Z MOLD CAP H2 DETAIL B DETAIL A<br>141-Lead (15mm (Reference LTC DWG # 05-08-1899 Rev D) A A1 A2 b b1 D E e F G H1 H2 aaa bbb ccc ddd eee<br>Øb (141 PLACES) SYMBOL<br>aaa  Z<br>0.0000<br>D X 6.9850 5.7150 4.4450 3.1750 1.9050 0.6350 0.6350 1.9050 3.1750 4.4450 5.7150 6.9850<br>Y<br>E<br>TOP VIEW<br>PACKAGE TOP VIEW<br>SUGGESTED PCB LAYOUT<br>4<br>PIN “A1” CORNER<br>0.630 ±0.025 Ø 141x<br>Z<br>Z<br>Z//  bbb<br>6.9850<br>5.7150<br>4.4450<br>3.1750<br>1.9050<br>0.6350<br>0.0000<br>0.6350<br>1.9050<br>3.1750<br>4.4450<br>5.7150<br>6.9850<br>aaa  Z<br>**----- End of picture text -----**<br>


Rev. G 

26 

For more information www.analog.com 

LTM4609 

## **REVISION HISTORY (Revision history begins at Rev B)** 

|**RE**|**ISIO**|**N HISTORY**<br>**(Revision history begins at Rev B)**||
|---|---|---|---|
|**REV**|**DATE**|**DESCRIPTION**|**PAGE NUMBER**|
|B|10/10|MP-grade part added. Reflected throughout the data sheet.|1-26|
|C|03/12|Added the BGA Package option and updated the Typical Applications.<br>Updated the Pin Configuration and Order Information sections.<br>Updated Note 2.<br>Added INTVCCmaximum load current.<br>Updated the recommended heat sinks table.<br>Added BGA Package drawing.<br>Updated the Related Parts section.|1<br>2<br>4<br>7<br>19<br>26<br>28|
|D|12/12|Added to Absolute Maximum Ratings and Thermal Resistance figures.<br>Augmented INTVCClimits.<br>Updated Note 2 and Note 3.<br>Updated Related Parts table.|2<br>4<br>4<br>28|
|E|1/14|Added SnPb terminal finish product option.|1, 2|
|F|4/14|Removed CLOCK SYNC, Figures 16, 17, 18, 19.|21, 22|
|G|11/22|Changed lead to pin in the Pin Configuration drawing.<br>Changed MSL Rating to 4.<br>Rearranged Pin Functions alphanumeric.<br>Deleted Manufacturer’s phone numbers.<br>Added ink marking statement to package photos.<br>Added Design Resources section.<br>Updated Related Parts section.|2<br>2<br>7<br>17<br>28<br>28<br>28|



Rev. G 

27 

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LTM4609 

## **PACKAGE PHOTOS** 

## **Part marking is either ink mark or laser mark** 

## **DESIGN RESOURCES** 

|**DESIGN RESOURCES**|||
|---|---|---|
|**SUBJECT**|**DESCRIPTION**||
|µModule Design and Manufacturing Resources|Design:<br>• Selector Guides<br>• Demo Boards and Gerber Files<br>• Free Simulation Tools|Manufacturing:<br>• Quick Start Guide<br>• PCB Design, Assembly and Manufacturing Guidelines<br>• Package and Board Level Reliability|
|µModule Regulator Products Search|1.  Sort table of products by parameters and download the result as a spread sheet.<br>2. Search using the Quick Power Search parametric table.<br>INPUT |<br>Vin(Min)<br>Vv<br>Vin(Max)<br>Vv<br>OUTPUT |<br>Vout<br>Vv<br>lout<br>A<br>FEATURES |<br>Low EMI<br>Ultrathin<br>Internal Heat Sink<br>{search)||
|Digital Power System Management|Analog Devices’ family of digital power supply management ICs are highly integrated solutions that<br>offer essential functions, including power supply monitoring, supervision, margining and sequencing,<br>and feature EEPROM for storing user configurations and fault logging.||



## **RELATED PARTS** 

|**PART NUMBER **|**DESCRIPTION**|**COMMENTS**|
|---|---|---|
|LTM4605|20VIN, 16VOUTBuck-Boost µModule Regulator;<br>External Inductor|4.5V ≤ VIN≤ 20V, 0.8V ≤ VOUT≤ 16V; 15mm × 15mm × 2.8mm BGA|
|LTM4607|36VIN, 24VOUTBuck-Boost µModule Regulator;<br>External Inductor|4.5V ≤ VIN≤ 36V, 0.8V ≤ VOUT≤ 24V; 15mm × 15mm × 3.42mm BGA|
|LTM4693|Ultrathin, Low VIN, 2A Buck-Boost µModule Regulator|2.6V ≤ VIN≤ 5.5V, 1.8V ≤ VOUT≤ 5.5V; 3.5mm × 4mm × 1.25mm LGA|
|LTM8054|36VIN, 36VOUT, 5.4A Buck-Boost µModule Regulator|5V ≤ VIN≤ 36V, 1.2V ≤ VOUT≤ 36V; 11.25mm × 15mm × 3.42mm BGA|
|LTM8055|36VIN, 36VOUT, 8.5A Buck-Boost µModule Regulator|5V ≤ VIN≤ 36V, 1.2V ≤ VOUT≤ 36V; 15mm × 15mm × 4.92mm BGA|
|LTM8056|58VIN, 48VOUT, 5.5A Buck-Boost µModule Regulator|5V ≤ VIN≤ 58V, 1.2V ≤ VOUT≤ 48V; 15mm × 15mm × 4.92mm BGA|
|LTM8083|36VIN, 36VOUT, 1.5A Buck-Boost µModule Regulator|3V ≤ VIN≤ 36V, 1V ≤ VOUT≤ 36V; 6.25mm × 6.25mm × 2.22mm BGA|
|LTM8045|Single; Inverting or SEPIC µModule DC/DC Convertor|2.8V ≤ VIN≤ 18V; ±2.5V ≤ VOUT≤ ±15V; 6.25mm × 11.25mm × 4.92mm BGA|
|LTM8049|Dual Outputs, SEPIC and/or Inverting µModule Regulator|2.6V ≤ VIN≤ 20V; ±2.5V ≤ VOUT≤ ±25V; 9mm × 15mm × 2.42mm BGA|



Rev. G 

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