Datasheet

DMS-20LCD Series
3½ Digit, LCD Display Digital Panel Voltmeters
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com/dpm
www.murata-ps.com
email: [e-mail]
05 Apr 2011 MPM_DMS20LCD.B08 Page 1 of 6
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 incorporate 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 800k:. 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
■
Lowest cost
■
Lowest power, 2mW
■
Subminiature size:
1.38" x 0.88" x 0.43"
35mm x 22mm x 11mm
■
Large (0.37"/9.4mm), enhanced-contrast LCD display
■
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
SIMPLIFIED SCHEMATIC DIAGRAM
(+) INPUT HI
(–) INPUT LO
ANALOG
COMMON
REFERENCE OUT
REFERENCE IN
+5V SUPPLY/
+BATTERY
R1
DP 1
DP 2
DP 3
6
5
4
9
11
12
10
8
7
1
3
DC/DC
CONVERTER
2
5V RETURN/
–BATTERY
+5V
–5V
R2
≈
+2.0V
DATA
909k
V+
V–
A/D
CONVERTER
0 Vdc
0.01μF
N.C.
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.
J1
DC/DC converter is not used on 9V-powered models,
J1 is connected.
N.C./BACKLIGHT
Used on backlit models only.
N.C. for non-backlit models.
+5V
Only used on ±200mV (-0) and ±2V (-1) models.
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