DPM 742-BL

DPM 1AS-BL 

3½ Digit Backlit LCD Voltmeter Module 

## **PRODUCT DESCRIPTION** 

The DPM 1AS-BL features a 200mV d.c. measurement range with auto-zero and auto-polarity. Decimal points are user selectable. The DPM 1AS-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 1AS-BL is intended to replace the DPM 1, DPM 1S, DPM 1-BL and DPM 1S-BL in many applications, usually requiring only minor circuit modifications. 

## **FEATURES** 

- 5.5mm (0.22") 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 1AS-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<br>~~es~~|9.0<br>~~es~~|15.0**<br>~~ee~~|V d.c.<br>~~ee~~|
|Meter supply current<br>~~as~~|V+ to GND<br>configuration<br>~~as~~|~~as~~<br>~~es~~|350<br>~~es~~|~~ee~~|A<br>~~ee~~|
||V+ to V-<br>configuration<br>~~as~~|~~as~~<br>~~es~~|175<br>~~es~~|~~ee~~<br>~~|~~|A<br>~~ee~~|
|Backlight supplyvoltage||4.75<br>~~es~~|5.0<br>~~es ~~|***<br> ~~ee ~~|V d.c.<br> ~~ee~~|
|Backlight supplycurrent@5V d.c.|||15|30****|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. **** This specification linearly derates to 20mA @ 50°C. 

Unless otherwise noted, specifications apply at T =25°C, V supply =5Vd.c. (f clock =48kHz) and are tested with the module configured for single ended 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). 

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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>


DPM 1AS-BL 

3½ Digit Backlit LCD Voltmeter Module 

## **DIMENSIONS** 

All dimensions in mm (inches) 

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30.0 (1.18) c<br>28.0 (1.10) a b d<br>_—<br>a0<br>0.50 (0.02) 2.00 (0.08) 5.00 (0.20)<br>pin width pin pitch<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: 28.4 x 11.4 Panel thickness: 1.0 - 2.5<br>(1.12 x 0.45) (0.04 - 0.10)<br>Panel<br>Module<br>_ |<br>Uy ,<br>1 2<br>1.26 (0.05)<br>14.0 (0.55) 11.0 (0.43)<br>**----- End of picture text -----**<br>


## **PANEL FITTING** 

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FUNCTIONAL BLOCK DIAGRAM PIN CONFIGURATION (rear view)<br>V+ BL-<br>Vref<br>CAL<br>CAL<br>LXDP LCOM<br>1 10<br>INHI<br>A/D<br>+_ = 1 8 ————S<br>INLO<br>CU<br>V- GND DP3 2 1 XDP<br>V+ GND V- BL- INHI INLO DP1 DP2 DP3 XDP<br>**----- End of picture text -----**<br>


3½ Digit Backlit LCD Voltmeter Module 

## DPM 1AS-BL 

## **CIRCUIT DIAGRAM** 

## **PIN FUNCTIONS** 

1. V+ Positivepowersupplytothemeter. 2. GND 0Vpowersupplytothemeter (3.0to7.5Vmeterpowersupplyapplicationsonly). 3. V- Negativepowersupplytothemeter(6.0to15.0Vmeterpowersupplyapplicationsonly). 4. BLConnecttothemeter'snegativesupplyvoltagetoswitchontheLEDbacklighting. Formetersupplyvoltagesabove5V,addaseriesresistorRs. SeeApplicationsforsuitablecircuitdiagrams. 5. INHI Positivemeasuringinput. 6. INLO Negativemeasuringinput. 7. DP1 ConnecttoXDPtodisplayDP1(199.9). 8. DP2 ConnecttoXDPtodisplayDP2(19.99). 9. DP3 ConnecttoXDPtodisplayDP3(1.999). 10. XDP Connect to pin 7, 8 or 9 to display required decimal point. 

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 thatofthepanelmeter,thenthelimitationsontheinputrangeare(V-+1.5V)to(V+-1.5V). 

## SolderLinks: 

LCOM NormallyOpen. ConnectsINLOtoCOM. LXDP NormallyClosed. Cutthislinktodisabletheinternaldecimalpointdrivecircuitandthereby reducethemeter'scurrentconsumption. 

3½ Digit Backlit LCD Voltmeter Module 

## DPM 1AS-BL 

## **SCALING** 

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



## **APPLICATIONS** 

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

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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>1 1 1<br>V+ No DP V+ V+<br>5 5 5<br>+ INHI DP1 7 + INHI I+ INHI<br>8<br>DP2 9 ±200mV BL- 4 Rb<br>±200mV DP3<br>10 - 6 INLO I- 6 INLO<br>- 6 INLO XDP<br>if V+>5V then<br>GND GND Rs=(V+ - 5V) GND<br>0.015<br>2 2 2<br>Dat 0V 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 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 LCOM is open. Ensure solder link LCOM is closed. Ensure solder link LCOM 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>1 1 1<br>V+ V+ V+<br>5 5 5<br>+ INHI + INHI I+ INHI<br>±200mV BL- 4 ±200mV BL- 4 Rb<br>- 6 INLO I- 6 INLO<br>6<br>- INLO<br>V- Rs=(V+) - (V-) - 5V V- Rs=(V+ - 5V) V-<br>0.015 0.015<br>3 3 3<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 hy and the meter's power supply are isolated ha i.e. the current and the meter's power l<br>supply share the same 0V rail. from each other. supply are isolated from each other.<br>Ensure solder link LCOM is open. Ensure solder link LCOM is closed. Ensure solder link LCOM is closed.<br>Specifications liable to change without prior warning DPM 1AS-BL Issue 7 06/2010 S.L. Applies to DPM 1AS-BL/2<br>**----- End of picture text -----**<br>