ETC DPM3AS-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
ORDERING INFORMATION
• Precision Instrumentation Systems
• Power Supply Monitoring
• Hand held instruments
• Panel-Mount Indication
• Low Power Voltage Measurement
Stock Number
DPM 3AS-BL
Standard Meter
ELECTRICAL SPECIFICATIONS
Specification
Min.
Typ.
Max.
Accuracy (overall error) *
0.1
Linearity
±1
Sample rate
2.5
Operating temperature range
0
50
Temperature stability
250
Meter supply voltage
V+ to GND configuration
3.0
5.0
7.5
V+ to Vconfiguration
6.0
9.0
15.0**
Meter supply current
V+ to GND configuration
350
175
V+ to Vconfiguration
Backlight supply voltage
4.75
5.0
***
Backlight supply current @ 5V d.c.
40
60
Input leakage current (Vin = 0V)
1
10
* 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.
Unit
% (±1 count)
count
samples/sec
°C
ppm/°C
V d.c.
V d.c.
µA
µA
V d.c.
mA
pA
Unless otherwise noted, specifications apply at TA=25°C, Vsupply=5Vd.c. (fclock=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
Laboratory Use).
LASCAR ELECTRONICS LTD.
MODULE HOUSE
WHITEPARISH
WILTSHIRE SP5 2SJ
UK
TEL: +44 (1794) 884567
FAX: +44 (1794) 884616
E-mail: [email protected]
LASCAR ELECTRONICS INC.
3750 WEST 26th STREET
ERIE
PA 16506
USA
TEL: +1 (814) 835 0621
FAX: +1 (814) 838 8141
E-mail: [email protected]
www.lascarelectronics.com
LASCAR ELECTRONICS (HK) LIMITED
FLAT C, 5/FL., LUCKY FTY. BLDG.
63-65 HUNG TO ROAD
KWUN TONG
KOWLOON
HONG KONG
TEL: +852 2797 3219
FAX: +852 2343 6187
E-mail: [email protected]
Page 2 of 4
Page 1 of 4
DPM 3AS-BL
3½ Digit Backlit LCD Voltmeter Module
DIMENSIONS
All dimensions in mm (inches)
2.54 (0.1)
pin pitch
6.00 (0.24)
a
b
d
13.5 (0.53)
17.5 (0.69)
20.0 (0.79)
2.00 (0.08)
c
0.50 (0.02)
pin width
37.5 (1.48)
40.0 (1.57)
Panel cut-out: 38.0 x 18.0
(1.50 x 0.71)
a.
b.
c.
d.
Panel thickness: 1.0 - 2.5
(0.04 - 0.10)
2.00
6.00
1.60
6.00
(0.08)
(0.24)
(0.06)
(0.24)
PANEL FITTING
Panel
Module
1
2
FUNCTIONAL BLOCK DIAGRAM
L+
V+
INLO
CAL
DP2
12
13
DP3
V-
IN LO
IN HI
COM
REF LO
REF HI
GND
DP1
1
BAT
A/D
+
_
TEST
CAL
L+
LREF
TEST
V+
BAT
11
L-
COM
REF HI
REF LO
INHI
(rear view)
L-
XDP
Vref
PIN CONFIGURATION
1
V-
GND
BAT
8
XDP
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Page 2 of 4
Page 2 of 4
DPM 3AS-BL
3½ Digit Backlit LCD Voltmeter Module
CIRCUIT DIAGRAM
V+
8
R10
100k
LREF
1
C1
47nF
R9
3k
INHI
INLO
COM
C2
220nF
3
2
4
C4
100nF
R3
1.5k
REF HI
REF LO
GND
6
5
7
C6
1u5
V-
L+
C7
1u5
R4
C5
47pF 180k
28
V+
INT
BUF
R1 29
A/Z
180k
31
IN HI
30
IN LO
32
COM
34
CREF+
33
CREF36
REF HI
35
REF LO
38
OSC3
39
OSC2
40
OSC1
a1
b1
c1
d1
e1
f1
g1
a2
b2
c2
d2
e2
f2
g2
a3
b3
c3
d3
e3
f3
g3
ab
POL
BP
V- TEST
37
26
IC1
5
4
3
2
8
6
7
12
11
10
9
14
13
25
23
16
24
15
18
17
22
19
20
21
a1
b1
c1
d1
e1
f1
g1
a2
b2
c2
d2
e2
f2
g2
a3
b3
c3
d3
e3
f3
g3
ab
POL
COM
DP1
DP2
DP3
22R
LED1
DP3
1.999
LOBAT
V+
13
DP2
19.99
R8
1M
R7
1M
R6
1M
BAT
R2
1M
R11
DP1
199.9
LCD1
1
LED2
L-
27
11
BAT
R5
100k
Q1
BCX19
12
10
9
XDP
TEST
PIN FUNCTIONS
1.
2.
3.
4.
VINLO
INHI
COM
5.
6.
7.
8.
9.
REF LO
REF HI
GND
V+
TEST
10.
11.
XDP
BAT
12.
13.
LL+
Negative power supply to the meter (6.0 to 15.0V meter power supply applications only).
Negative measuring input.
Positive measuring input.
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 (>100µA) by, for instance, connecting to a higher voltage.
Negative input for reference voltage.
Positive input for reference voltage.
0V power supply to the meter (3.0 to 7.5V meter power supply applications only).
Positive power supply to the meter.
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 to
power external logic up to a maximum of 1mA.
V+
8
4077
Inversion of LCD drive voltage.
V+
10
1M
1M
XDP
Low Battery annunciator drive pin. See application on the right.
11
BAT
This pin is not fitted as standard.
Negative power supply to LED backlighting.
9
Positive power supply to LED backlighting.
TEST
BC 237
The backlighting is internally configured for 5V operation.
470k
VIf a higher voltage is used, then add a series current limiting resistor Rs.
SET
THRESHOLD
1
See Applications for calculations of Rs.
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 Vis -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:
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.
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Page 3 of 4
DPM 3AS-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 the module.
Voltage
(Vin)
Current
(Iin)
FSR
2V
20V
200V
2000V*
200µA
2mA
20mA
200mA
Ra
910k
1M
1M
1M
0R
0R
0R
0R
Rb
100k
10k
1k
100R
1k
100R
10R
1R
Ra
+
1M
Vin or Iin
Rb
INHI
10nF
DPM 3AS-BL
-
INLO
Input Filter
*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
1M
+
±200mV
+3.0 to +7.5V
8
V+
3
+
INHI
±200mV
10nF
2
INLO
4
COM
5
-
1M
V+
3
INHI
L+
10nF
L-
2
INLO
4
COM
5
-
REF LO
GND
7
+3.0 to +7.5V
8
13
if V+>5V then
Rs=(V+ - 5V)
0.04
1M
I+
12
Rb
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 LREF is closed.
3
INHI
10nF
2
INLO
4
COM
5
I-
REF LO
GND
REF LO
GND
7
0V
8
V+
7
0V
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 LREF is closed.
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 LREF is closed.
9V supply operation (6.0 to 15.0V Meter Power Supply)
+3.0 to +7.5V
1M
+
±200mV
-
8
+6.0 to +15.0V
V+
3
+
INHI
±200mV
10nF
2
INLO
4
COM
5
-
REF LO
V-
-3.0 to -7.5V
1M
V+
3
INHI
Rs=(V+ - 5V)
0.04
L+
10nF
L-
2
INLO
4
COM
5
13
1M
I+
12
Rb
INHI
10nF
1
0V
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 LREF is closed.
DPM 3AS-BL
3
REF LO
V-
1
Specifications liable to change without prior warning
8
V+
2
INLO
4
COM
5
I-
REF LO
V-
1
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 LREF is closed.
+6.0 to +15.0V
8
Issue 4
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 LREF is closed.
December/2002
www.lascarelectronics.com
0V
M.C.
Applies to DPM 3AS-BL/5
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