DPM 1AS-BL 3‰Digit Backlit LCD Voltmeter Module PRODUCT DESCRIPTION The DPM 1AS-BL featuresa 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 ORDERING INFORMATION � Precision Instrumentation Systems Stock Number � Power Supply Monitoring Standard Meter DPM 1AS-BL � Hand held instruments � Panel-Mount Indication � Low Power Voltage Measurement ELECTRICAL SPECIFICATIONS Specification Min. Typ. Max. Unit Accuracy (overall error) * 0.1 % (–1 count) Linearity –1 count Sample rate 2.5 samples/sec Operating temperature range 0 50 �C Temperature stability 250 ppm/�C Meter supply voltage V+ to GND configuration 3.0 5.0 7.5 V d.c. V+ to V- configuration 6.0 9.0 15.0** V d.c. Meter supply current V+ to GND configuration 350mA V+ to V- configuration 175mA Backlight supply voltage 4.75 5.0 *** V d.c. Backlight supply current @ 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 =5Vd.c. (f =48kHz) and are tested with the module configured for single ended A supply clock 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 Laboratory Use). P Page age2o 2 off4 4 www.martelmeters.com page 1 of 4 DPM 1AS-BL 3‰Digit Backlit LCD Voltmeter Module DIMENSIONS All dimensions in mm (inches) c 30.0 (1.18) ab d 28.0 (1.10) 0.50 (0.02) 2.00 (0.08) 5.00 (0.20) pin width pin pitch a. 2.00 (0.08) b. 6.00 (0.24) c. 1.60 (0.06) d. 6.00 (0.24) Panel cut-out: 28.4 x 11.4 Panel thickness: 1.0 - 2.5 (1.12 x 0.45) (0.04 - 0.10) PANEL FITTING Panel Module 1 2 PIN CONFIGURATION (rear view) FUNCTIONAL BLOCK DIAGRAM V+ BL- Vref CAL CAL LXDP LCOM 110 INHI + A/D _ 1 8 INLO V- GND DP3 2 1 XDP P Page age2o 2 off4 4 www.lascarelectronics.com www.martelmeters.com page 2 of 4 14.0 (0.55) 11.0 (0.43) V+ GND V- BL- INHI INLO DP1 1.26 (0.05) DP2 DP3 XDP DPM 1AS-BL 3‰Digit Backlit LCD Voltmeter Module CIRCUIT DIAGRAM PIN FUNCTIONS 1. V+ Positive power supply to the meter. 2. GND 0V power supply to the meter (3.0 to 7.5V meter power supply applications only). 3. V- Negative power supply to the meter (6.0 to 15.0V meter power supply applications only). 4. BL- Connect to the meter’s negative supply voltage to switch on the LED backlighting. For meter supply voltages above 5V, add a series resistor Rs. See Applications for suitable circuit diagrams. 5. INHI Positive measuring input. 6. INLO Negative measuring input. 7. DP1 Connect to XDP to display DP1 (199.9). 8. DP2 Connect to XDP to display DP2 (19.99). 9. DP3 Connect to XDP to display DP3 (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 that of the panel meter, then the limitations on the input range are (V- + 1.5V) to (V+ - 1.5V). Solder Links: LCOM Normally Open. Connects INLO to COM. LXDP Normally Closed. Cut this link to disable the internal decimal point drive circuit and thereby reduce the meter’s current consumption. www.lascarelectronics.com www.martelmeters.com page 3 of 4 DPM 1AS-BL 3‰Digit Backlit LCD Voltmeter Module SCALING Two external resistors Ra FSR Ra Rb and Rb may be used to 2V 910k 100k Ra + INHI alter the full scale reading Voltage 20V 1M 10k (Vin) 200V 1M 1k (FSR) of the meter - see Vin or Iin Rb 2000V* 1M 100R DPM 1AS-BL table. The meter will have 200mA 0R 1k to be re-calibrated by Current 2mA 0R 100R - INLO adjusting the calibration (Iin) 20mA 0R 10R potentiometer on the rear 200mA 0R 1R of the module. *Ensure that Ra is rated for high voltage use. APPLICATIONS Do not connect more than one meter to the same power supply if the meters cannot use the same signal ground. Taking any input beyond the power supply rails will damage the meter. 5V supply operation (3.0 to 7.5V Meter Power Supply) +3.0 to +7.5V +3.0 to +7.5V +3.0 to +7.5V 1 11 V+ V+ V+ No DP 5 55 7 + INHI + INHI I+ INHI DP1 8 DP2 4 Rb 9 –200mV BL- DP3 –200mV 66 - INLO I- INLO 10 6 XDP - INLO if V+>5V then Rs=(V+ - 5V) GND GND GND 0.015 2 22 0V 0V 0V Measuring a single ended input Measuring an input voltage referenced to Measuring a current from a circuit which is voltage referenced to supply, i.e. the a floating supply, i.e. the input voltage floating with respect to the DPM’s supply, input voltage and the meter’s power and the meter’s power supply are isolated i.e. the current and the meter’s power supply share the same 0V rail. from each other. supply are isolated from each other. Ensure solder link LCOM is open. Ensure solder link LCOM is closed. Ensure solder link LCOM is closed. 9V supply operation (6.0 to 15.0V Meter Power Supply) +3.0 to +7.5V +6.0 to +15.0V +6.0 to +15.0V 11 1 V+ V+ V+ 55 5 + INHI + INHI INHI I+ 4 4 Rb –200mV BL- BL- –200mV 66 - INLO I- INLO 6 - INLO Rs=(V+) - (V-) - 5V Rs=(V+ - 5V) V- V- V- 0.015 0.015 33 3 0V -3.0 to -7.5V 0V Measuring a single ended input Measuring an input voltage referenced to Measuring a current from a circuit which is voltage referenced to supply, i.e. the a floating supply, i.e. the input voltage floating with respect to the DPM’s supply, input voltage and the meter’s power and the meter’s power supply are isolated i.e. the current and the meter’s power supply are isolated from each other. supply share the same 0V rail. from each other. Ensure solder link LCOM is closed. Ensure solder link LCOM is open. Ensure solder link LCOM is closed. Specifications liable to change without prior warning DPM 1AS-BL Issue3 February/2002 M.C. Applies to DPM 1AS-BL/2 P Page age4o 4 off4 4 www.martelmeters.com page 4 of 4