DPM 3AS-BL

DPM 3AS-BL 

3½ Digit Backlit LCD Voltmeter Module 

## **PRODUCT DESCRIPTION** 

The DPM 3AS-BL features a 200mV d.c. measurement range with auto-zero and auto-polarity. Decimal points are user selectable. The DPM 3AS-BL features a negative rail generator which enables the meter to measure a signal referenced to its own power supply GND. LED backlighting ensures excellent readability under low light conditions. The design of the panel meter's housing allows the module to be easily snapped into a panel. The module's low cost means it will suit high and low volume applications. The DPM 3AS-BL is intended to replace the DPM 3, DPM 3S, DPM 3-BL and DPM 3S-BL in many applications, usually requiring only minor circuit modifications. 

## **FEATURES** 

- 11mm (0.43") Digit Height 

- 200mV d.c. Full Scale Reading 

- 3.0 to 7.5V or 6.0 to 15.0V Operation 

- Auto-zero and Auto-polarity 

- • Programmable Decimal Points • LED Backlighting 

## **TYPICAL APPLICATIONS** 

- Precision Instrumentation Systems 

- Power Supply Monitoring 

- Hand held instruments 

## **ORDERING INFORMATION** 

Stock Number Standard Meter **DPM 3AS-BL** 

- Panel-Mount Indication 

- Low Power Voltage Measurement 

## **ELECTRICAL SPECIFICATIONS** 

|**Specification**|**Specification**|**Min.**|**Typ.**|**Max.**|**Unit**|
|---|---|---|---|---|---|
|Accuracy (overall error)*|||0.1||%(±1 count)|
|Linearity||||±1|count|
|Sample rate|||2.5||samples/sec|
|Operatingtemperature range||0||50|°C|
|Temperature stability|||250||ppm/°C|
|Meter supply voltage|V+ to GND<br>configuration|3.0|5.0|7.5|V d.c.|
||V+ to V-<br>configuration|6.0|9.0|15.0**|V d.c.|
|Meter supply current<br>~~as~~<br>~~a~~|V+ to GND<br>configuration<br>~~as~~|~~eses~~|350<br>~~eses~~|~~ee~~|A<br>~~eeee~~|
||V+ to V-<br>configuration<br>~~as~~<br>~~a~~|~~eses~~|175<br>~~eses~~<br>~~eS~~|~~ee~~|A<br>~~eeee~~|
|Backlight supplyvoltage<br>~~a~~||4.75|5.0<br>~~eS~~|***|V d.c.|
|Backlight supplycurrent@5V d.c.<br>~~a~~|||40<br>~~eS~~|60|mA|
|Input leakage current (Vin = 0V)|||1|10|pA|



* To ensure maximum accuracy, re-calibrate periodically. 

** Operation of the meter beyond the maximum supply voltage rating may cause permanent damage to the meter. *** An external series resistor is required above 5V, see Applications. Unless otherwise noted, specifications apply at T =25°C, V supply =5Vd.c. (f clock =48kHz) and are tested with the module configured for fully floating input mode. 

## **SAFETY** 

To comply with the Low Voltage Directive (LVD 93/68/EEC), input voltages to the module’s pins must not exceed 60Vdc. The user must ensure that the incorporation of the panel meter into the user’s equipment conforms to the relevant sections of BS EN 61010 (Safety Requirements for Electrical Equipment for Measuring, Control and LaboratoryUse). 

**==> picture [483 x 59] intentionally omitted <==**

**----- Start of picture text -----**<br>
LASCAR ELECTRONICS LTD. LASCAR ELECTRONICS INC. LASCAR ELECTRONICS (HK) LTD.<br>MODULE HOUSE 4258 WEST 12th STREET 8th FLOOR, CHINA AEROSPACE CENTRE,<br>WHITEPARISH ERIE 143 HOI BUN ROAD,<br>WILTSHIRE SP5 2SJ PA 16505 KWUN TONG, KOWLOON,<br>UK USA HONG KONG<br>TEL: +44 (1794) 884567 TEL: +1 (814) 835 0621 TEL: +852 2389 6502<br>FAX: +44 (1794) 884616 FAX: +1 (814) 838 8141 FAX: +852 2389 6535<br>E-MAIL: sales@lascar.co.uk E-MAIL: us-sales@lascarelectronics.com E- mail: saleshk@lascar.com.hk<br>**----- End of picture text -----**<br>


3½ Digit Backlit LCD Voltmeter Module 

## DPM 3AS-BL 

## **DIMENSIONS** 

All dimensions in mm (inches) 

**==> picture [426 x 173] intentionally omitted <==**

**----- Start of picture text -----**<br>
2.54 (0.1)<br>pin pitch c<br>0.50 (0.02)<br>pin width 6.00 (0.24) a b d<br>ctlwwu IP,<br>LE 37.5 (1.48)<br>40.0 (1.57)<br>a. 2.00 (0.08)<br>b. 6.00 (0.24)<br>c. 1.60 (0.06)<br>d. 6.00 (0.24)<br>Panel cut-out: 38.0 x 18.0 Panel thickness: 1.0 - 2.5<br>(1.50 x 0.71) (0.04 - 0.10)<br>)8<br>(00.<br>0<br>20.<br>)3<br>(05.<br>35.<br>1<br>)9 )9<br>(07. (60.<br>00. 75.<br>2 1<br>**----- End of picture text -----**<br>


## **PANEL FITTING** 

**==> picture [483 x 437] intentionally omitted <==**

**----- Start of picture text -----**<br>
Panel<br>Module<br>|<br>1 2<br>U , b .<br>FUNCTIONAL BLOCK DIAGRAM PIN CONFIGURATION (rear view)<br>V+ L+ L-<br>Vref<br>CAL<br>11 1<br>COM<br>REF HI LREF CAL<br>12<br>REF LO DP2 DP1 DP3 BAT<br>13<br>INHI<br>A/D<br>+_ 1 8<br>INLO =<br>TEST V- GND BAT XDP<br>2) ~<br>Page 2 of 4<br>www.lascarelectronics.com No: 695 Page 2 of 4<br>uascR<br>ABT PDX STET V+ GND REFHI OREFL CMO NIHI NOIL V-<br>-L L+<br>**----- End of picture text -----**<br>


DPM 3AS-BL 

3½ Digit Backlit LCD Voltmeter Module 

## **CIRCUIT DIAGRAM** 

**==> picture [442 x 263] intentionally omitted <==**

**----- Start of picture text -----**<br>
8<br>V+<br>R10<br>100k | LREF 1<br>REF LOREF HICOMINLOGNDINHI 325746 C6 ht R93k os———— R31.5k C7 — C5 100nF220nF47nFR4C4C1C2 180kR1 27282931303234333635383940 BUFA/ZIN HIIN LOCOMCREF+CREF-REF HIREF LOINTOSC3OSC2OSC1 IC1V+ POLBPd1d3d2b1b2b3abe1e3e2a2a3a1c1c2c3g1g2g3f1f2f3 ————= —— 5432867121110914132523162415181722192021 POLd1e1f1b1g1a2b2f2g2a3d3e3f3c1c2d2b3g3a1e2c3abCOM LCD1 LOBATDP1DP2DP3 ee—_ 199.919.991.999 R81M ; R71M R61MDP1DP2DP3<br>1u5 1u5 47pF 180k V- TEST<br>| = 26 37 _ BAT Uf<br>1<br>V- S e<br>V+<br>11<br>BAT<br>R11 R2<br>L+ 13 1M R5<br>_— 22R 100k<br>Q1<br>LED2 Vy WS LED1 3 BCX19 | 10 XDP<br>WAN N ys -<br>12<br>L- 9<br>TEST<br>**----- End of picture text -----**<br>


## **PIN FUNCTIONS** 

1. V- Negativepowersupplytothemeter(6.0to15.0Vmeterpowersupplyapplicationsonly). 2. INLO Negativemeasuringinput. 3. INHI Positivemeasuringinput. 4. COM GroundfortheanaloguesectionoftheA/Dconverter.Itisactivelyheldat3.05V(nom.)belowV+andmustnotbe allowedtosinkexcessivecurrent(>100 A)by,for instance,connectingtoahighervoltage. 

5. REFLO Negativeinputforreferencevoltage. 6. REFHI Positiveinputforreferencevoltage. 7. GND 0Vpowersupplytothemeter (3.0to7.5Vmeterpowersupplyapplicationsonly). 8. V+ Positivepowersupplytothemeter. 9. TEST ConnecttoV+totesttheLCD.DonotconnecttoV+formorethanafewsecondsasthismaydamagetheLCD. TESTisheldactivelyat5V(nom.)belowV+andisthegroundforthedigitalsectionofthemeter.Itcanbeusedto powerexternallogicuptoamaximumof1mA. V+ 

10.11. XDPBAT Inversion of LCD drive voltage.Low Battery annunciator drive pin. See application on the right. 10 XDP V+8 This pin is not fitted as standard. q ~~i~~ 11 BAT 

12. L- Negative power supply to LED backlighting. 13. L+ Positive power supply to LED backlighting. ~~ae~~ 9 TEST The backlighting is internally configured for 5V operation. If a higher voltage is used, then add a series current limiting resistor Rs. V- See Applications for calculations of Rs. ~~q~~ e 1 **Check Link BAT is OPEN.** 

Note: 

A negative supply is generated internally and mirrors the positive supply. For example: if V+ is +5V, then the internally generated V- is -5V. When measuring with the input referenced to the same supply rail as that of the panel meter, then the limitations on the input rangeare(V-+1.5V)to(V+-1.5V). 

## SolderLinks: 

LREF NormallyClosed. Enablestheinternalvoltagereferencecircuit.Cutthislinkwhenusinganexternalvoltagereference. BAT NormallyOpen. DisablestheLowBatterywarningannunciator.Cutthislinkandaddalowbatterydetectioncircuit toenabletheLowBatterywarningannunciatorviaPin11(BAT). DP1 NormallyOpen. ClosethissolderlinktoenabledecimalpointDP1. DP2 NormallyOpen. ClosethissolderlinktoenabledecimalpointDP2. DP3 NormallyOpen. ClosethissolderlinktoenabledecimalpointDP3. 

www.lascarelectronics.com | 

3½ Digit Backlit LCD Voltmeter Module 

## DPM 3AS-BL 

## **SCALING** 

|Two external resistors Ra<br>and Rb may be used to<br>alter the full scale reading<br>(FSR) of the meter - see<br>table. The meter will have|(Vin)<br>Voltage|**FSR**<br>2V<br>20V<br>200V<br>2000V*||**Ra**<br>910k<br>1M<br>1M<br>1M||**Rb**<br>100k<br>10k<br>1k<br>100R|+<br>Vin or|in<br>I|in<br>I|Ra||||Rb||1M<br>10nF|||INHI<br>DPM 3AS-BL|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|to be re-calibrated by<br>adjusting the calibration<br>potentiometer on the rear<br>ofthemodule.|200 A<br>0R<br>2mA<br>0R<br>( in)<br>20mA<br>0R<br>200mA<br>0R<br>I<br>Current<br>*Ensure that Ra is rated for high voltage use.|||||1k<br>100R<br>10R<br>1R|-||||||||Input Filter||||INLO|



## **APPLICATIONS** 

Do not connect more than one meter to the same power supply if the meters cannot use the same signal ground. Takinganyinputbeyondthepowersupplyrailswilldamagethemeter. 

**==> picture [467 x 443] intentionally omitted <==**

**----- Start of picture text -----**<br>
5V supply operation (3.0 to 7.5V Meter Power Supply)<br>+3.0 to +7.5V +3.0 to +7.5V +3.0 to +7.5V<br>8 8 8<br>if V+>5V then<br>V+ V+ Rs=(V+ - 5V) V+<br>1M 3 1M 3 0.04 1M 3<br>+ INHI + INHI 13 I+ INHI<br>L+<br>±200mV 10nF ±200mV 10nF L- 12 Rb 10nF<br>- 2 INLO - 2 INLO I- 2 INLO<br>4 4 4<br>COM COM COM<br>5 5 5<br>REF LO REF LO REF LO<br>GND GND GND<br>7 7 7<br>0V 0V 0V<br>4) x<br>Measuring a single ended input Measuring an input voltage referenced to Measuring a current from a circuit which is<br>voltage referenced to supply, i.e. the a floating supply, i.e. the input voltage floating with respect to the DPM's supply,<br>input voltage and the meter's power and the meter's power supply are isolated i.e. the current and the meter's power<br>supply share the same 0V rail. from each other. supply are isolated from each other.<br>Ensure solder link LREF is closed. Ensure solder link LREF is closed. Ensure solder link LREF is closed.<br>9V supply operation (6.0 to 15.0V Meter Power Supply)<br>+3.0 to +7.5V +6.0 to +15.0V +6.0 to +15.0V<br>8 8 8<br>V+ V+ Rs=(V+ - 5V) V+<br>1M 1M 0.04 1M<br>3 3 3<br>+ INHI + INHI 13 I+ INHI<br>L+<br>±200mV 10nF ±200mV 10nF L- 12 Rb 10nF<br>- 2 INLO - 2 INLO I- 2 INLO<br>4 4 4<br>COM COM COM<br>5 5 5<br>REF LO REF LO REF LO<br>V- V- V-<br>1 1 1<br>-3.0 to -7.5V 0V 0V<br>Measuring a single ended input Measuring an input voltage referenced to Measuring a current from a circuit which is<br>voltage referenced to supply, i.e. the a floating supply, i.e. the input voltage floating with respect to the DPM's supply,<br>input voltage and the meter's power DO and the meter's power supply are isolated i.e. the current and the meter's power +<br>supply share the same 0V rail. from each other. supply are isolated from each other.<br>Ensure solder link LREF is closed. Ensure solder link LREF is closed. Ensure solder link LREF is closed.<br>**----- End of picture text -----**<br>


_**Specifications liable to change without prior warning**_ **DPM 3AS-BL Issue 9 05/2013 S.L. Applies to DPM 3AS-BL/5**