DMS-40LCD-4 Datasheet, PDF (1/5 Pages) Murata Power Solutions Inc. – Ultra-Low 2.9V Loop-Drop 4½ Digit LCD Display Process Monitor

DMS-40LCD-4/20S Series
Ultra-Low 2.9V Loop-Drop 4½ Digit
LCD Display Process Monitor
FEATURES
N Loop-powered, no power supply required!
N 2.9V typical loop-drop; 190-Ohm (max.) loop
impedance
N Dip-switch-selectable range, offset, and
decimal points
N Hundreds of different input/readout combinations
N Non-interacting gain (span) and offset (zero)
20-turn potentiometers
N Large, 0.40" (10.0mm) high, sunlight-viewable
LCD digits
N Miniature size: 2.17" x 0.92" x 0.90" (55mm x
23mm x 23mm)
N Vibration-resistant package; reliable screw-
terminal connections
N 100% soldered connections
R3
R7
ZERO
ADJUST
GAIN
ADJUST
BAND-GAP
REFERENCE
CIRCUIT
The DMS-40LCD-4/20S’s ultra-low 2.9V typical loop-drop (190-Ohm burden) makes it
ideal for use in 4-20mA process monitoring applications which have two or more series-
connected loop-monitoring devices. The low loop-burden means it can be used in current
loops that are powered from supply voltages as low as +8Vdc! The DMS-40LCD-4/20S is
self-powered; all required operating power is derived directly from the current loop itself.
It requires no separate dc power supply or special grounding considerations and can be
connected ANYWHERE in the loop!
The DMS-40LCD-4/20S's input, span, and offset circuits all employ super-stable,
±0.5% thin-film chip resistors. Long-term stability and accuracy are assured by driving
these tight-tolerance resistors with an ultra-stable, ±0.2% band-gap voltage reference.
Unlike many competitor’s designs, the two precision 20-turn span and zero adjust poten-
tiometers do not interact with one another. Its full-size, 0.40" (10.0mm) high-contrast 4½
digit LCD display offers 19,999 counts of resolution and can be read in virtually any lighting
condition—including full sunlight!
All range-change and decimal point selections are made by configuring two gold-plat-
ed, vibration-resistant, six-position DIP switches. The two connections to the current loop
are made via a reliable, screw-type terminal block. To further enhance reliability, the design
features 100% soldered connections—no troublesome zebra/elastomercic connectors are
used. All these outstanding features make the DMS-40LCD-4/20S the highest quality, most
rugged, 4½ digit, LCD-display process monitor available.
4½ DIGIT A/D
CONVERTER
Range
Offset Gain
DATA
DP1
DP2
DP3
DP4
ON
S1
1 234 56
ON
S2
1 234 56
Ḥ
For full details go to
www.murata-ps.com/rohs
+5V
–5V
DC/DC
CONVERTER
CURRENT TO
VOLTAGE
CONVERTER
Figure 1. DMS-40LCD-4/20S Simplified Schematic
TB1
+–
1
2
+–
4-20mA
Current Loop Input
www.murata-ps.com
Technical enquiries email: [e-mail], tel: [phone]
MPM_DMS401LCD-420S.D02 Page 1 of 5