MURATA DMS-20LCD User Manual

DMS-20LCD Series

3½ Digit, LCD Display Digital Panel Voltmeters

FEATURES

N

Lowest cost

N

Lowest power, 2mW

N

Subminiature size:

1.38" x 0.88" x 0.43"
35mm x 22mm x 11mm

N

Large (0.37"/9.4mm), enhanced-contrast LCD display

N

Epoxy-encapsulated, 12-pin DIP

N

Panel or pc-board mountable

N

4 differential input voltage ranges

N

High accuracy, ±1 count (±0.05%)

N

Single +5V supply or 9V battery

N

Low-battery annunciator

N

User-selectable decimal point placement

N

0 to +60°C temperature range

SIMPLIFIED SCHEMATIC DIAGRAM

N.C.

1

2

3

+5V SUPPLY/

+BATTERY

5V RETURN/

–BATTERY

DC/DC

CONVERTER

0 Vdc

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 800k7. 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.

+5V

3

J1

–5V

A/D

CONVERTER

V+

2

+2.0V

z

R2

0.01μF

V–

1

R1

909k

12

(–) INPUT LO

11

(+) INPUT HI

10

ANALOG
COMMON

For full details go to

www.murata-ps.com/rohs

4

DP 3

5

DP 2

6

DP 1

1

R2 is not used on ±200mV (-0) models or ±2V (-1) models.
R2 = 100k on ±20V (-2) models and 9.1k on ±200V (-3) model s.

2

Only used on ±200mV (-0) and ±2V (-1) models.

DATA

www.murata-ps.com Technical enquiries email: [e-mail], tel: [phone]

9

N.C./BACKLIGHT

8

+5V

3

DC/DC converter is not used on 9V-powered models,
J1 is connected.

4

Used on backlit models only.
N.C. for non-backlit models.

REFERENCE OUT

7

REFERENCE IN

MPM_DMS20lcd.B03 Page 1 of 6

4

Performance/Functional Specifications

Typical at TA = +25°C and supply voltage = +5V (using the single-ended input
circuit) or +9V (using the differential input circuit), unless otherwise noted.

Analog Inputs Min. Typ. Max. Units

Full Scale Input Range:

DMS-20LCD-0 – ±200 – mV

DMS-20LCD-1 – ±2 – Volts

DMS-20LCD-2 – ±20 – Volts

DMS-20LCD-3 – ±200 – Volts

Input Impedence: –

DMS-20LCD-0, -1 100 1000 –

DMS-20LCD-2, -3 0.8 1 –

Overvoltage Protection ~

DMS-20LCD-0, -1, -2 – – ±100 Volts

DMS-20LCD-3 – – ±250 Volts

Common Mode Voltage Range – – ±2 Volts

CMRR (dc to 60Hz) – 86 – dB

Control Inputs 

Decimal Pt. Placement (Pins 4-6) Tie to pin 3 to activate

Functionality Tie to pin 3 to activate

Logic Compatibility TTL (on 5V-powered models)

Backlight (Pin 9) Tie to pin 3 to turn on backlight

Performance

Sampling Rate 2.5 reading per second

Accuracy (1 minute warm-up):

DMS-20PC-0 (Vin = +0.19V) – ±1 ±2 Counts

DMS-20PC-1 (Vin = +1.9V) – ±1 ±2 Counts

DMS-20PC-2 (Vin = +19V) – ±2 ±3 Counts

DMS-20PC-3 (Vin = +190V) – ±2 ±3 Counts

Zero Reading (Vin = 0 Volts) “–001” “000” “001”

Temperature Drift (0 = +60°C) – ±0.2 ±0.4 Cnts/°C

Power Supply Requirements (5V Models)

Supply Voltage +4.75 +5.00 +5.25 Volts

Supply Current:

Standard Models – +400 +650 μA

Backlit Models – +35 +50 mA

Power Supply Requirements (9V Models)

Supply Voltage +7.5 +9.0 +14.0 Volts

Supply Current:

Standard Models – +230 +350 μA

Backlit Models – +35 +50 mA

Display

Display Type and Size 3½ digit, 0.37"/9.4mm high LCD

Polarity Indication Autopolarity ("–" for negative Vin)

Overrange Indication "–1_ __ " for negative Vin

"1_ __ " for positive Vin

M7

M7

DMS-20LCD Series

3½ Digit, LCD Display Digital Panel Voltmeters

Physical/Environmental

Operating Temperature 0 – +60 °C

Storage Temperature –20 – +75 °C

Humidity (non-condensing) 0–95%

Case Material Polycarbonate

Weight 0.4 ounces (11 grams)

~ Applies for transient or continuous overvoltages applied to (+) INPUT HI
(pin 11) with (–) INPUT LO (pin 12) properly connected. Pin 12 is not
overvoltage
protected (see Figure 1). Voltages applied to pin 12 should not exceed the
supply voltage.

 Listed spec applies to 5V-powered models only. For 9V-powered models, both
(–) INPUT LO (pin 12) and (+) INPUT HIGH (pin 11) must always be at least

1.5V above –BATTERY (pin 3) and at least 1.5V below +BATTERY (pin 1).

 See Technical Notes.

Ordering Information

DMS-20LCD - 1 - 5 - C

Add -C for RoHS

Input Range:
0 = ±200mV
1 = ±2V
2 = ±20V
3 = ±200V

Accessories:

DMS-20-CP Panel cutout punch
DMS-BZL3-C DMS-20 bezel assembly
DMS-BZL4-C DMS-20 bezel assembly with sealing gasket
DMS-EB2-C Application/evaluation board with standard
MOLEX connector, decimal point solder pads
and attenuation resistor pads.

A panel-mount retaining clip is supplied with each model.

TECHNICAL NOTES

1. REFERENCE OUTPUT (Pin 8) and INPUT (Pin 7): Pin 8 is a precision

reference actively trimmed at the factory. In normal operation, pin 8

must be tied to pin 7 to achieve all listed accuracy and drift specifica-

tions.

2. ANALOG COMMON (Pin 10): This pin is connected to an internal,

low-noise, “relative” ground. It is used in certain differential and “float-

ing” measurements as described in the Applications section of this

data sheet and Ap Note 3 of the DATEL Panel Meter Catalog. Pin 10

should not be connected to pin 3 (5V RETURN/–BATTERY) or to

your system’s analog ground.

3. Decimal Point Placement: The location of the decimal point is user-

selectable, and the decimal point control pins (DP1-DP3) are active low

functions. Select the appropriate decimal point by tying the appropriate

pin (pin 4, 5 or 6) to pin 3 (5V RETURN/–BATTERY). Unused decimal

Leave blank for standard
models.
Add B for backlit models.

Power Source:
5 = +5V
9 = +9V

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

MPM_DMS20lcd.B03 Page 2 of 6