OEM 1B
3½ Digit LCD Voltmeter Module
PRODUCT DESCRIPTION
The OEM 1B uses the latest miniaturisation techniques to produce a very compact 3 ½ digit LCD voltmeter. It is
designed to be a drop-in component in most medium and high volume applications, ranging from personal
instrumentation and integral sensor indicators to measurement probes. The meter features 8mm digit height, 3
decimal points, auto-polarity, auto-zero, 200mV full scale reading and a very low current consumption.
Connection to the module is via two dual in line rows of pins.
FEATURES
• 8mm (0.31") Digit Height
• 200mV d.c. Full Scale Reading
• 150µA @ 7.5 to 14V Operation
• Auto-zero and Auto-polarity
• Selectable Decimal Points
• Very Compact Design
TYPICAL APPLICATIONS
ORDERING INFORMATION
• Personal Gas Monitoring
• Medical Instruments
• Measurement Probes
• Hand held instruments
Stock Number
OEM 1B
Standard Meter
ELECTRICAL SPECIFICATIONS
Specification
Accuracy (overall error) *
Linearity
Sample rate
Operating temperature range
Temperature stability
Supply voltage (V+ to V-)
Supply current
Input leakage current (Vin = 0V)
Min.
0
7.5
Typ.
0.1
2.5
100
9
150
1
Max.
Unit
% (±1 count)
count
samples/sec
°C
ppm/°C
V d.c.
µA
pA
+1
50
14**
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.
Unless otherwise noted, specifications apply at TA=25°C, Vsupply=5Vd.c. (fclock=48kHz) and are tested with the module configured for 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: sales@lascar.co.uk
LASCAR ELECTRONICS INC.
3750 West 26th Street
Erie
PA 16506
USA
TEL: +1 (814) 835 0621
FAX: +1 (814) 838 8141
E-mail: us-sales@lascarelectronics.com
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: b4lascar@samsongroup.com.hk
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OEM 1B
3½ Digit LCD Voltmeter Module
DIMENSIONS
All dimensions in mm (inches)
5.3 (0.21)
CAL
5.5
(0.22)
13.4 (0.53)
16.4 (0.65)
+0.4(0.02)
6.35
(0.25)
1.27 (0.05)
12.7 (0.50)
23.4 (0.92)
+0.2(0.01)
17.8 (0.70)
5.0
(0.20)
5.5 (0.22)
FUNCTIONAL BLOCK DIAGRAM
2.54 (0.10)
PIN CONFIGURATION
(rear view)
V+
DP2
DP3
XDP
I LO
IHI
V+
V-
ILO
DP1
CAL
RLO
INI
COM
Vref
CAL
NC
COM
RHI
RHI
R LO
A/D
+
_
XDP
1
V-
8
DP3 2 1
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OEM 1B
3½ Digit LCD Voltmeter Module
CIRCUIT DIAGRAM
NC
PIN FUNCTIONS
1.
2.
3.
VV+
IHI
4.
ILO
5.
COM
6.
7.
8.
9.
10.
11.
12.
RLO
RHI
NC
DP1
DP2
DP3
XDP
Negative power supply to the meter.
Positive power supply to the meter.
Positive measuring input.
IHI must be no closer than 1.6V to either the positive or negative supply, when using the
internal 100mV reference.
Negative measuring input.
ILO must be no closer than 1.6V to either the positive or negative supply, when using the
internal 100mV reference.
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 (>100mA) by, for instance, connecting
to a higher voltage.
Negative input for the reference voltage.
Positive input for the reference voltage.
Do not connect.
Connect to XDP to display DP1 (199.9).
Connect to XDP to display DP2 (19.99).
Connect to XDP to display DP3 (1.999).
Connect to DP1, DP2 or DP3 to display required decimal points.
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OEM 1B
3½ Digit LCD Voltmeter Module
SCALING
Two 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 recalibrated by adjusting the
calibration potentiometer
on the rear of the module.
FSR
2V
20V
200V
2000V*
200µA
2mA
20mA
200mA
Voltage
Vin
Current
Iin
Ra
910k
1M
1M
1M
0R
0R
0R
0R
Rb
100k
10k
1k
100R
1k
100R
10R
1R
+
Ra
Vin or Iin
IHI
Rb
OEM 1B
-
ILO
*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.
+
±200mV
-
3
4
5
6
IHI
2
V+
V+
±200mV
ILO
+
3
-
4
COM
RLO
V1
3
+
R-
R=0.2
IFSR
5
6
2
V+
IIN
100K
2K
SET
3
4
ZERO
6
RLO
4 ILO
5
V-
Measuring current.
Supply MUST be isolated.
14V max
7V min
6
SUPPLY
VOLTAGE
IOUT
IHI
2
V+
4
V-
V+
IHI
5
COM
10K
510K
Split supply operation.
6R2
COM
COM
5
V1
V-
V+
3
RLO
1.6V
min.
IHI
V1
ILO
2
V+
510K
IHI
0V
Measuring a floating voltage
source of 200mV full scale.
V+
2
V+
ILO
6
RLO
V1
V-
Measuring a supply voltage.
(min. 7.5V, max. 14V).
V+
ILO
RLO
COM
V1
V-
Measuring 4-20mA to read 0-999.
Supply MUST be isolated.
Specifications liable to change without prior warning
OEM 1B
Issue 2
September/2002
www.lascarelectronics.com
M.C.
Applies to OEM 1B/3
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