BULD741T4

Bipolar (BJT) Single Transistor, NPN, 1.05 kV, 2.5 A, 30 W, TO-252 (DPAK), Surface Mount

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Manufacturer: STMICROELECTRONICS
Product type:
Transistor Polarity:NPN; Collector Emitter Voltage V(br)ceo:1.05kV; Transition Frequency ft:-; Power Dissipation Pd:30W; DC Collector Current:2; Available until stocks are exhausted
MSL: MSL 1 - Unlimited
SVHC: No SVHC (17-Dec-2015)
No. of Pins: 3Pins
Product Range: -
Qualification: -
Power Dissipation: 30W
Transistor Mounting: Surface Mount
Transistor Polarity: NPN
Transition Frequency: -
Transistor Case Style: TO-252 (DPAK)
DC Current Gain hFE Min: 25hFE
Operating Temperature Max: 150°C
Continuous Collector Current: 2.5A
Collector Emitter Voltage Max: 1.05kV

Delivery and price
Units per pack	10
Price	0.813 €
Current stock	50+
Lead time	30 days

Datasheet

**BULD741** 

High voltage fast-switching NPN power transistor 

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## **Features** 

- High voltage capability 

- Low spread of dynamic parameters 

- Minimum lot-to-lot spread for reliable operation 

- Very high switching speed 

## **Description** 

The device is manufactured using high voltage Multi-Epitaxial Planar technology for high switching speeds and high voltage capability. 

Thanks to an increased intermediate layer, it has an intrinsic ruggedness which enables the transistor to withstand an high collector current level during breakdown condition, without using the transil protection usually necessary in typical converters for lamp ballast. 

## **Applications** 

- Electronic ballast for fluorescent lighting 

- Switch mode power supplies. 

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3 3<br>2<br>1<br>1<br>DPAK IPAK<br>TO-252 TO-251<br>**----- End of picture text -----**<br>


## **Figure 1. Internal schematic diagram** 

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**Table 1. Device summary** 

|**Order codes**|**Marking**|**Package**|**Packaging**|
|---|---|---|---|
|BULD741T4|BULD741|DPAK|Tape & reel|
|BULD741-1|BULD741|IPAK|Tube|



1/11 

July 2007 

Rev 2 

_www.st.com_ 

**Electrical ratings** 

**BULD741** 

## **1 Electrical ratings** 

## **Table 2. Absolute maximum rating** 

|**Table 2.**|**Absolute maximum rating**|||
|---|---|---|---|
|**Symbol**|**Parameter**|**Value**|**Unit**|
|VCES|Collector-emitter voltage (VBE= 0)|1050|V|
|VCEO|Collector-emitter voltage (IB= 0)|400|V|
|VEBO|Emitter-base voltage (IC= 0, IB= 2A, tP< 10ms)|V(BR)EBO|V|
|IC|Collector current|2.5|A|
|ICM|Collector peak current (tP< 5ms)|5|A|
|IB|Base current|1.5|A|
|IBM|Base peak current (tP< 5ms)|3|A|
|Ptot|Total dissipation at Tc= 25°C|30|W|
|Tstg|Storage temperature|-65 to 150|°C|
|TJ|Max. operating junction temperature|150|°C|



## **Table 3. Thermal data** 

|**Table 3.**|**Thermal data**|||
|---|---|---|---|
|**Symbol**|**Parameter**|**Value**|**Unit**|
|Rthj-case|Thermal resistance junction-case__max|4.16|°C/W|



2/11 

**Electrical characteristics** 

**BULD741** 

## **2 Electrical characteristics** 

(Tcase = 25°C unless otherwise specified) 

## **Table 4. Electrical characteristics** 

|**Symbol**|**Parameter**|**Test conditions**|**Min.**|**Typ.**|**Max.**|**Unit**|
|---|---|---|---|---|---|---|
|ICES|Collector cut-off current<br>(VBE=0V)|VCE=1050V||0.2|10|µA|
|ICEO|Collector cut-off current<br>(IB=0)|VCE=400V||10|250|µA|
|V(BR)EBO|Emitter-base breakdown<br>voltage (IC= 0)|IE=1mA|15|19|24|V|
|VCEO(sus)<br>(1)|Collector-emitter<br>sustaining voltage<br>(IB= 0)|IC=10mA|400|450||V|
|VCE(sat)<br>(1)|Collector-emitter<br>saturation voltage|IC=0.7A              IB=0.14A<br>IC=2A                 IB=0.6A||0.15<br>0.5|0.5<br>1.5|V<br>V|
|VBE(sat)<br>(1)|Base-emitter saturation<br>voltage|IC=2A                 IB=0.6A||1.1|1.5|V|
|hFE|DC current gain|IC=0.1A             VCE=5V<br>IC=0.45A           VCE=3V|48<br>25|70<br>35|100<br>50||
|ts<br>tf|Resistive load<br>Storage time<br>Fall time|VCC=125V         IC=1A<br>IB1= -IB2=0.2A   tp= 300µs<br>VBE(off)=-5V||2.5<br>350|3.5<br>500|µs<br>ns|
|Ear|Repetitive avalanche<br>energy|L =2mH              C =1.8nF<br>VBE(off)=-5V|5|||mJ|



Note (1) Pulsed duration = 300 µ s, duty cycle ≤ 1.5% 

3/11 

**Electrical characteristics** 

**BULD741** 

## **2.1 Electrical characteristics (curves)** 

**Figure 2. Safe operating area** 

## **Figure 3. Derating curve** 

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**Figure 4. Output characteristics** 

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**Figure 5. Reverse biased safe operating area** 

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**Figure 6. DC current gain** 

**Figure 7. DC current gain** 

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4/11 

**Electrical characteristics** 

**BULD741** 

## **Figure 8. Base-emitter saturation Figure 9. Collector-emitter saturation voltage voltage** 

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## **Figure 10. Resistive load switching on times** 

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## **Figure 11. Resistive load switching on times** 

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**Figure 12. Resistive load switching off times** 

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## **Figure 13. Resistive load switching off times** 

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5/11 

**Electrical characteristics** 

**BULD741** 

## **2.2 Test circuits** 

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**----- Start of picture text -----**<br>
Figure 14. Resistive load switching test circuit<br>1) Fast electronic switch<br>2) Non-inductive resistor<br>**----- End of picture text -----**<br>


## **Figure 15. Energy rating test circuit** 

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6/11 

**Package mechanical data** 

**BULD741** 

## **3 Package mechanical data** 

In order to meet environmental requirements, ST offers these devices in ECOPACK® packages. These packages have a Lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com 

7/11 

**Package mechanical data** 

**BULD741** 

||||||||||**inch**<br>**MAX.**<br>**MIN.**<br>**TYP.**<br>**MAX.**<br>2.40<br>0.087<br>0.094<br>1.10<br>0.035<br>0.043<br>0.23<br>0.001<br>0.009<br>0.90<br>0.025<br>0.035<br>5.40<br>0.204<br>0.213<br>0.60<br>0.018<br>0.024<br>0.60<br>0.019<br>0.024<br>6.20<br>0.236<br>0.244<br>6.60<br>0.252<br>0.260<br>4.60<br>0.173<br>0.181<br>10.10<br>0.368<br>0.398<br>0.031<br>1.00<br>0.024<br>0.039<br>8o<br>0o<br>0o<br>P032P_B<br>**) MECHANICAL DATA**|**inch**<br>**MAX.**<br>**MIN.**<br>**TYP.**<br>**MAX.**<br>2.40<br>0.087<br>0.094<br>1.10<br>0.035<br>0.043<br>0.23<br>0.001<br>0.009<br>0.90<br>0.025<br>0.035<br>5.40<br>0.204<br>0.213<br>0.60<br>0.018<br>0.024<br>0.60<br>0.019<br>0.024<br>6.20<br>0.236<br>0.244<br>6.60<br>0.252<br>0.260<br>4.60<br>0.173<br>0.181<br>10.10<br>0.368<br>0.398<br>0.031<br>1.00<br>0.024<br>0.039<br>8o<br>0o<br>0o<br>P032P_B<br>**) MECHANICAL DATA**|**inch**<br>**MAX.**<br>**MIN.**<br>**TYP.**<br>**MAX.**<br>2.40<br>0.087<br>0.094<br>1.10<br>0.035<br>0.043<br>0.23<br>0.001<br>0.009<br>0.90<br>0.025<br>0.035<br>5.40<br>0.204<br>0.213<br>0.60<br>0.018<br>0.024<br>0.60<br>0.019<br>0.024<br>6.20<br>0.236<br>0.244<br>6.60<br>0.252<br>0.260<br>4.60<br>0.173<br>0.181<br>10.10<br>0.368<br>0.398<br>0.031<br>1.00<br>0.024<br>0.039<br>8o<br>0o<br>0o<br>P032P_B<br>**) MECHANICAL DATA**|**inch**<br>**MAX.**<br>**MIN.**<br>**TYP.**<br>**MAX.**<br>2.40<br>0.087<br>0.094<br>1.10<br>0.035<br>0.043<br>0.23<br>0.001<br>0.009<br>0.90<br>0.025<br>0.035<br>5.40<br>0.204<br>0.213<br>0.60<br>0.018<br>0.024<br>0.60<br>0.019<br>0.024<br>6.20<br>0.236<br>0.244<br>6.60<br>0.252<br>0.260<br>4.60<br>0.173<br>0.181<br>10.10<br>0.368<br>0.398<br>0.031<br>1.00<br>0.024<br>0.039<br>8o<br>0o<br>0o<br>P032P_B<br>**) MECHANICAL DATA**|
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|||||||**T**|**O-252 (DPAK**||**) MECHANICAL DATA**||||
||||||||||||||
|||**DIM**||||||**mm**|||**inch**||
|||**.**|||**MI**|**N.**||**TYP.**|**MAX**|**.**<br>**M**|**IN.**<br>**TYP.**|**MAX.**|
|||A|||2.2|0|||2.40|0.|087|0.094|
|||A1|||0.9|0|||1.10|0.|035|0.043|
|||A2|||0.0|3|||0.23|0.|001|0.009|
|||B|||0.6|4|||0.90|0.|025|0.035|
|||B2|||5.2|0|||5.40|0.|204|0.213|
|||C|||0.4|5|||0.60|0.|018|0.024|
|||C2|||0.4|8|||0.60|0.|019|0.024|
|||D|||6.0|0|||6.20|0.|236|0.244|
|||E|||6.4|0|||6.60|0.|252|0.260|
|||G|||4.4|0|||4.60|0.|173|0.181|
|||H|||9.3|5|||10.1|0<br>0.|368|0.398|
|||L2||||||0.8|||0.031||
|||L4|||0.6|0|||1.00|0.|024|0.039|
|||V2|||0o||||8o|0|o|0o|
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||||||||||||P032P_B||
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8/11 

**Package mechanical data** 

**BULD741** 

## **TO-251 (IPAK) MECHANICAL DATA** 

|**DIM**|**mm**|**mm**|**mm**|**inch**|**inch**|**inch**|
|---|---|---|---|---|---|---|
|**.**|**MIN.**|**TYP.**|**MAX.**|**MIN.**|**TYP.**|**MAX.**|
|A|2.20||2.40|0.087||0.094|
|A1|0.90||1.10|0.035||0.043|
|A3|0.70||1.30|0.028||0.051|
|B|0.64||0.90|0.025||0.035|
|B2|5.20||5.40|0.204||0.213|
|B3|||0.85|||0.033|
|B5||0.30|||0.012||
|B6|||0.95|||0.037|
|C|0.45||0.60|0.018||0.024|
|C2|0.48||0.60|0.019||0.024|
|D|6.00||6.20|0.237||0.244|
|E|6.40||6.60|0.252||0.260|
|G|4.40||4.60|0.173||0.181|
|H|15.90||16.30|0.626||0.642|
|L|9.00||9.40|0.354||0.370|
|L1|0.80||1.20|0.031||0.047|
|L2||0.80|1.00||0.031|0.039|
|V1||10o|||10o||



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P032N_E<br>**----- End of picture text -----**<br>


9/11 

**Revision history** 

**BULD741** 

## **4 Revision history** 

**Table 5. Revision history** 

|**Date**|**Revision**|**Changes**|
|---|---|---|
|20-Dec-2006|1|Initial release.|
|09-Jul-2007|2|Updated package names in page 1, added figure 4, updated<br>figure 12 and 13.|



10/11 

**BULD741** 

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11/11

Updated at April 27, 2026

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