PRODUCT DESCRIPTIONThe DPM 3AS-BL features a 200mV d.c. measurement range with auto-zero and auto-polarity. Decimal points are userselectable.
LED backlighting ensures excellent readability under low light conditions.easily snapped into a panel. The module's
The DPM 3AS-BL features a negative rail generator which enables the meter to measure a signal referencedto its own power supply GND. The designof the panel meter's housing allows the module to be low cost means it willsuit high and low volume applications. The DPM 3AS-BL is intended to replace the DPM 3, DPM 3S, DPM 3-BL andDPM 3S-BL in many applications, usually requiring only minor circuit modifications.
FEATURES• 11• 200mV d.c. Full Scale Reading• 3.0 to 7.5V or 6.0 to 15.0V Operation•••
mm (0.43") Digit Height
Programmable Decimal PointsLED Backlighting
Auto-zero and Auto-polarity
TYPICAL APPLICATIONS• Precision Instrumentation Systems• Power Supply Monitoring• Hand held instruments• Panel-Mount Indication• Low Power Voltage Measurement
ORDERING INFORMATIONStock Number
Standard Meter DPM 3AS-BL
DPM 3AS-BL 3½ Digit Backlit LCD Voltmeter Module
SAFETYTo comply with the Low Voltage Directive (LVD 93/68/EEC), input voltages to the module’s pins must not exceed60Vdc. The user must ensure that the incorporation of the panel meter into the user’s equipment conforms to therelevant sections of BS EN 61010 (Safety Requirements for Electrical Equipment for Measuring, Control andLaboratory Use).
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LASCAR ELECTRONICS LTD.MODULE HOUSEWHITEPARISHWILTSHIRE SP5 2SJUKTEL: +44 (1794) 884567FAX: +44 (1794) 884616E-mail: [email protected]
LASCAR ELECTRONICS (HK) LIMITEDFLAT C, 5/FL., LUCKY FTY. BLDG.63-65 HUNG TO ROADKWUN TONG KOWLOONHONG KONGTEL: +852 2797 3219FAX: +852 2343 6187E-mail: [email protected]
ELECTRICAL SPECIFICATIONSSpecification Min. Typ. Max. UnitAccuracy (overall error) * 0.1 % (±1 count)Linearity ±1 countSample rate 2.5 samples/secOperating temperature range 0 50 °CTemperature stability 250 ppm/°CMeter supply voltage V+ to GND configuration 3.0 5.0 7.5 V d.c.
175 ABacklight supply voltage 4.75 5.0 *** V d.c.Backlight supply current @ 5V d.c. 40 60 mAInput 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.
V+ to V- configuration 6.0 9.0 15.0** V d.c.Meter supply current V+ to GND configuration 350 A
V+ to V- configurationµµ
Unless otherwise noted, specifications apply at T =25°C, V =5Vd.c. (f =48kHz) and are tested with the module configured for fully floating
input mode.A supply clock
LASCAR ELECTRONICS INC.3750 WEST 26th STREETERIEPA 16506USATEL: +1 (814) 835 0621FAX: +1 (814) 838 8141E-mail: [email protected]
40.0 (1.57)
37.5 (1.48)
17
.5(0
.69
)
20
.0(0
.79
)
a. 2.00 (0.08)b. 6.00 (0.24)c. 1.60 (0.06)d. 6.00 (0.24)
0.50 (0.02)pin width 6.00 (0.24)
13
.5(0
.53
)
2.0
0(0
.08
)
2.54 (0.1)pin pitch
a b d
c
Panel thickness: 1.0 - 2.5(0.04 - 0.10)
Panel cut-out: 38.0 x 18.0(1.50 x 0.71)
DIMENSIONSAll dimensions in mm (inches)
DPM 3AS-BL 3½ Digit Backlit LCD Voltmeter Module
PANEL FITTING
PIN CONFIGURATION (rear view)FUNCTIONAL BLOCK DIAGRAM
Vref
Module
1
Panel
2
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1 8
A/D+_
INHI
REF HI
COM
INLO
REF LO
BAT XDPGND
V+
V-TEST
L-L+
CAL
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CALLREF
DP1DP2 DP3 BAT
11
12 13
1
BA
T
XD
PL-
TES
TL+
V+
GN
D
REF
HI
REF
LO
CO
M
INH
I
INLO V
-
DPM 3AS-BL 3½ Digit Backlit LCD Voltmeter Module
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CIRCUIT DIAGRAM
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PIN FUNCTIONS1. V- Negative power supply to the meter (6.0 to 15.0V meter power supply applications only).2. INLO Negative measuring input.3. INHI Positive measuring input.4. COM Ground for the analogue section of the A/D converter. It is actively held at 3.05V (nom.) below V+ and must not be
allowed to sink excessive current (>100 A) by, for instance, connecting to a higher voltage.5. REF LO Negative input for reference voltage.6. REF HI Positive input for reference voltage.7. GND 0V power supply to the meter (3.0 to 7.5V meter power supply applications only).8. V+ Positive power supply to the meter.9. TEST Connect to V+ to test the LCD. Do not connect to V+ for more than a few seconds as this may damage the LCD.
TEST is held actively at 5V (nom.) below V+ and is the ground for the digital section of the meter. It can be used topower external logic up to a maximum of 1mA.
10. XDP Inversion of LCD drive voltage.11. BAT Low Battery annunciator drive pin. See application on the right.
This pin is not fitted as standard.12. L- Negative power supply to LED backlighting.13. L+ Positive power supply to LED backlighting.
The backlighting is internally configured for 5V operation.If a higher voltage is used, then add a series current limiting resistor Rs.See Applications for calculations of Rs.
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 inputrange are (V- + 1.5V) to (V+ - 1.5V).
LREF Normally Closed. Enables the internal voltage reference circuit. Cut this link when using an external voltage reference.BAT Normally Open. Disables the Low Battery warning annunciator. Cut this link and add a low battery detection circuit
to enable the Low Battery warning annunciator via Pin 11 (BAT).DP1 Normally Open. Close this solder link to enable decimal point DP1.DP2 Normally Open. Close this solder link to enable decimal point DP2.DP3 Normally Open. Close this solder link to enable decimal point DP3.
µ
Note:
Solder Links:
V+8
3
2
4
6
5
7
1
13
12
INHI
INLO
COM
REF HI
REF LO
GND
V-
L+
L-
INTV+
V- TEST
a1 a127
1
26
28
29
31
30
32
34
36
35
33
d1 d1e1 e1f1 f1
DP1199.9
DP219.99
DP31.999
g1 g1
f2 f2
a2 a2
g2 g2
e3 e3
b2 b2
a3 a3
f3 f3
c2 c2
b3 b3
g3 g3
d2 d2
c3 c3
ab ab
e2 e2
d3 d3
b1 b1c1 c1
5
2867
13
12
25
18
11
23
17
10
16
22
9
24
19
14
15
43
BUF
A/Z
IN HI
IN LO
COM
CREF+
CREF-
REF HI
REF LO
IC1 LCD1
R4
R11
LED1LED2
180k
22R
47pF1u51u5C5C7C6
C4100nF
C147nF
R1180k
C2220nF
LREF
DP1
DP2
DP3
BAT
R10100k
R93k
R31.5k
37
POL POLBP COM
2021
40
39
38OSC3
OSC2
OSC1
10
11
9
V+
XDP
BAT
TEST
LOBAT
R81M
R5100k
R21M
Q1BCX19
R71M
R61M
Check Link BAT is OPEN.
V+
V+XDP
BAT
TEST
8
10
1V-
1M
470k
1M
4077
11
9
SETTHRESHOLD
BC 237
DPM 3AS-BL 3½ Digit Backlit LCD Voltmeter Module
Specifications liable to change without prior warning DPM 3AS-BL Issue 4 December/2002 M.C. Applies to DPM 3AS-BL/5
APPLICATIONSDo not connect more than one meter to the same power supply if the meters cannot use the same signalground. Taking any input beyond the power supply rails will damage the meter.
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SCALINGTwo external resistors Raand Rb may be used toalter the full scale reading(FSR) of the meter - seetable. The meter will haveto be re-calibrated byadjusting the calibrationpotentiometer on the rearof the module.
FSR Ra Rb2V 910k 100k
20V 1M 10k(Vin) 200V 1M 1k
2000V* 1M 100R200 A 0R 1k2mA 0R 100R
( in) 20mA 0R 10R200mA 0R 1R
µ
I
Voltage
Current
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*Ensure that Ra is rated for high voltage use.
5V supply operation (3.0 to 7.5V Meter Power Supply)
9V supply operation (6.0 to 15.0V Meter Power Supply)
Measuring a single ended inputvoltage referenced to supply, i.e. theinput voltage and the meter's powersupply share the same 0V rail.Ensure solder link LREF is closed.
Measuring a single ended inputvoltage referenced to supply, i.e. theinput voltage and the meter's powersupply share the same 0V rail.Ensure solder link LREF is closed.
Measuring a current from a circuit which isfloating with respect to the DPM's supply,i.e. the current and the meter's powersupply are isolated from each other.Ensure solder link LREF is closed.
Measuring a current from a circuit which isfloating with respect to the DPM's supply,i.e. the current and the meter's powersupply are isolated from each other.Ensure solder link LREF is closed.
Measuring an input voltage referenced toa floating supply, i.e. the input voltageand the meter's power supply are isolatedfrom each other.Ensure solder link LREF is closed.
Measuring an input voltage referenced toa floating supply, i.e. the input voltageand the meter's power supply are isolatedfrom each other.Ensure solder link LREF is closed.
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+3.0 to +7.5V
7
8
12
133
2
4
5
V+
INHI
INLO
COMREF LO
GND
+
-
±200mV
0V
L-
L+
if V+>5V thenRs=(V+ - 5V)
0.041M
10nF
+6.0 to +15.0V
1
8
12
133
2
4
5
V+
INHI
INLO
COMREF LO
V-
+
-
±200mV
0V
L-
L+
Rs=(V+ - 5V)0.041M
10nF
+3.0 to +7.5V
+6.0 to +15.0V
7
1
8
8
3
3
2
2
V+
V+
INHI
INHI
4
4
5
5
COM
COM
REF LO
REF LO
INLO
INLO
0V
0V
GND
V-
Rb
Rb
I+
I+
I-
I-
1M
1M
10nF
10nF
+3.0 to +7.5V
7
8
3
2
4
5
V+
INHI
INLO
COMREF LO
GND
+
-
±200mV
0V
1M
10nF
+3.0 to +7.5V
-3.0 to -7.5V1
8
3
2
4
5
V+
INHI
INLO
COMREF LO
V-
+
-
±200mV
1M
10nF
+
-
Ra 1M
Rb
INHI
Vin or inI
INLO
DPM 3AS-BL10nF
Input Filter