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www.datel.com
DMS-20LCD Se rie s
3½ Digit, LCD Display
Low-Cost, Subminiature
Digital Panel Voltmeters
Actual Size
DMS-20LCD Series, 3½ Digit, LCD Display, Digital Voltmeters represent the
ultimate combination of low price, low power, small size and high performance in digital
meters. Epoxy encapsulated in a subminiature (1.38" x 0.88" x 0.43"), 12-pin DIP
package, these completely self-contained, fully operational meters offer a combination
of ruggedness, long-term reliability and component-like ease-of-use simply not
available in any other meters.
Incorporating a precision reference and a factory-calibrated, autozeroing A/D
converter, DMS-20LCD meters are extremely accurate (±1 count) and are only slightly
larger than their 0.37"/9.4mm, enhanced-contrast, LCD displays. All models incorpo-
rate a built-in bezel and are easily mounted in either panels or pc boards. Both backlit
and non-backlit versions are available.
DMS-20LCD meters have 4 differential input voltage ranges (±200mV, ±2V, ±20V
and ±200V) and a user-friendly input structure. Input impedance is a minimum 800kΩ.
CMRR is typically 86dB with a CMV of ±2V. Non-inverting inputs are overvoltage
protected to ±100V (±250V for the ±200V input model).
All DMS-20LCD meters operate from a single +5V supply (drawing 400µA) or a
single +9V supply/battery (drawing 230µA). All models have a low-battery ("B")
annunciator and feature autopolarity changeover and overrange indication.
Also available is an application/evaluation board (DMS-EB2) that plugs directly onto
the back of any DMS-20LCD allowing direct inputs for common applications such as
4-20mA inputs, zero/gain adjust, decimal point location, and input voltage dividing.
Features
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Lowest cost
Lowest power, 2mW
Subminiature size:
1.38" x 0.88" x 0.43"
35mm x 22mm x 11mm
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Large (0.37"/9.4mm), enhanced-
contrast LCD display
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Backlit displays optional
Epoxy-encapsulated, 12-pin DIP
Panel or pc-board mountable
4 differential input voltage ranges
High accuracy, ±1 count (±0.05%)
Single +5V supply or 9V battery
Low-battery annunciator
User-selectable decimal point placement
0 to +60°C temperature range
+5V
12
1
V+
+5V SUPPLY/
+BATTERY
(–) INPUT LO
1
2
R2
0.01µF
–5V
3
R1
2
11
10
DC/DC
(+) INPUT HI
N.C.
CONVERTER
V–
909k
»
+2.0V
3
J1
ANALOG
COMMON
5V RETURN/
–BATTERY
A/D
CONVERTER
0 Vdc
DATA
4
5
6
9
8
7
4
DP 3
DP 2
DP 1
N.C./BACKLIGHT
REFERENCE OUT
REFERENCE IN
+5V
3
4
1
2
R2 is not used on 200mV (-0) models or 2V (-1) models.
R2 = 100k on 20V (-2) models and 9.1k on 200V (-3) models.
DC/DC converter is not used on 9V-powered models,
J1 is connected.
Only used on 200mV (-0) and 2V (-1) models.
Used on backlit models only.
N.C. for non-backlit models.
Figure 1. DMS-20LCD Series Simplified Schematic
DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356
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Email:sales@datel.com • Internet: www.datel.com