DPM 2AS-BL
3½ Digit Backlit LCD Voltmeter Module
PRODUCT DESCRIPTION
The DPM 2AS-BL features a 200mV d.c. measurement range with auto-zero andauto-polarity. Decimal points are user
selectable.
to its own power supply GND. The design
of the panel meter's housing allows the module to be low cost means it will
The DPM 2AS-BL features a negative rail generator whichenables the meter to measure a signal referenced
LED backlighting ensures excellent readability under low light conditions.
easily snapped into a panel. The module's
suit high and low volume applications. The DPM 2AS-BL is intended to replace the DPM 2, DPM 2S, DPM 2-BL and
DPM 2S-BL in many applications, usually requiring only minor circuit modifications.
FEATURES
mm (0.32") Digit Height
• 8.25
• 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
ORDERING INFORMATION
Stock Number
Standard Meter DPM 2AS-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.
Meter supply current V+ to GND configuration 350 A
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
input mode.
V+ to V- configuration 6.0 9.0 15.0** V d.c.
µ
V+ to V- configuration
A supply clock
175 A
µ
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 thatthe incorporationof thepanel 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).
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DPM 2AS-BL
DIMENSIONS
All dimensions in mm (inches)
3½ Digit Backlit LCD Voltmeter Module
Panel cut-out: 33.0 x 15.0
(1.30 x 0.59)
PANEL FITTING
Panel
Module
17.0 (0.67)
14.5 (0.57)
0.50 (0.02)
pin width
Panel thickness: 1.0 - 2.5
(0.04 - 0.10)
35.0 (1.38)
32.5 (1.27)
2.00 (0.08)
pin pitch
c
ab d
1.76 (0.07)
7.26 (0.28)
a. 2.00 (0.08)
b. 6.00 (0.24)
c. 1.60 (0.06)
d. 6.00 (0.24)
1
FUNCTIONAL BLOCK DIAGRAM
BL-
8
1
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INHI
INLO
V+
Vref
CAL
+
_
A/D
V-
DP3 2 1 XDPGND
2
DP1
LCOM
DP2
(rear view)
XDP
DP3
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PIN CONFIGURATION
GND
CAL
V-
INHI
BL-
INLO
LXDP
V+
DPM 2AS-BL
CIRCUIT DIAGRAM
3½ Digit Backlit LCD Voltmeter Module
PIN FUNCTIONS
1. V+ Positive powersupply to themeter.
2. GND 0Vpower supply tothe meter (3.0 to 7.5Vmeter power supply applicationsonly).
3. V- Negative power supplytothe meter (6.0to 15.0V meter power supplyapplications only).
4. BL- Connectto the meter's negativesupply voltage toswitch on the LEDbacklighting.
Formeter supplyvoltages above 5V, adda series resistor Rs.
See Applications forsuitablecircuit diagrams.
5. INHI Positive measuring input.
6. INLO Negative measuring input.
7. DP1 Connect toXDP to display DP1(199.9).
8. DP2 Connect toXDP to display DP2(19.99).
9. DP3 Connect toXDP 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 thepanel meter,then the limitationson the input rangeare (V-+ 1.5V)to (V+ - 1.5V).
Solder Links:
LCOM Normally Open. Connects INLO toCOM.
LXDP Normally Closed. Cut this linkto disable the internaldecimal pointdrive circuit and thereby
reduce the meter'scurrent consumption.
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DPM 2AS-BL
3½ Digit Backlit LCD Voltmeter Module
SCALING
Two external resistors Ra
and Rb may be used to
alter the full scale reading
(FSR) of the meter - see
table. The meter will have
to be re-calibrated by
adjusting the calibration
potentiometer on the rear
of themodule.
Voltage
(Vin) 200V 1M 1k
Current
I
( in) 20mA 0R 10R
*Ensure that Ra is rated for high voltage use.
FSR Ra Rb
2V 910k 100k
20V 1M 10k
2000V* 1M 100R
200 A 0R 1k
µ
2mA 0R 100R
200mA 0R 1R
+
Vin or inI
-
Ra
Rb
INHI
DPM 2AS-BL
INLO
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 thepower supply railswill damagethe meter.
5V supply operation (3.0 to 7.5V Meter Power Supply)
+3.0 to +7.5V
+
5
±200mV
-
Measuring a single ended input
voltage referenced to supply, i.e. the
input voltage and the meter's power
supply share the same 0V rail.
Ensure solder link LCOM is open.
6
INHI
INLO
1
V+
DP1
DP2
DP3
XDP
GND
2
No DP
7
8
9
10
0V
+3.0 to +7.5V
55
+
INHI
±200mV
-
Measuring an input voltage referenced to
a floating supply, i.e. the input voltage
and the meter's power supply are isolated
from each other.
Ensure solder link LCOM is closed.
66
INLO
9V supply operation (6.0 to15.0V Meter PowerSupply)
+3.0 to +7.5V
+
±200mV
-
-3.0 to -7.5V
11 1
V+
5545
INHI
4
BL-
6
INLO
V-
33 3
+6.0 to +15.0V
+
±200mV
-
Rs=(V+) - (V-) - 5V
0.015
INHI
66
INLO
11
V+
BL-
if V+>5V then
GND
22
Rs=(V+ - 5V)
0V
+3.0 to +7.5V
V+
I+
Rb
I-
0.015
INHI
INLO
GND
0V
Measuring a current from a circuit which is
floating with respect to the DPM's supply,
i.e. the current and the meter's power
supply are isolated from each other.
Ensure solder link LCOM is closed.
+6.0 to +15.0V
V+
V-
BL-
4
Rs=(V+ - 5V)
0.015
0V
I+
Rb
I-
V+
INHI
INLO
V-
0V
Measuring a single ended input
voltage referenced to supply, i.e. the
input voltage and the meter's power
supply share the same 0V rail.
Ensure solder link LCOM is open.
Specifications liable to change without prior warning DPM 2AS-BL Issue 2 February/2002 M.C. Applies to DPM 2AS-BL/1
Measuring an input voltage referenced to
a floating supply, i.e. the input voltage
and the meter's power supply are isolated
from each other.
Ensure solder link LCOM is closed.
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Measuring a current from a circuit which is
floating with respect to the DPM's supply,
i.e. the current and the meter's power
supply are isolated from each other.
Ensure solder link LCOM is closed.
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