DATEL DMS-EB2, DMS-20LCD-2-5, DMS-20LCD-1-9B, DMS-20LCD-1-9, DMS-20LCD-1-5B Datasheet

DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: [phone] Fax: [phone] • Email: [e-mail] • Internet: www.datel.com

Features

Figure 1. DMS-20LCD Series Simplified Schematic

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 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 changeov er 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.

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Lowest cost

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Lowest power, 2mW

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Subminiature size:

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

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Large (0.37"/9.4mm), enhanced­contrast LCD display

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Backlit displays optional

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Epoxy-encapsulated, 12-pin DIP

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Panel or pc-board mountable

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4 differential input voltage ranges

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High accuracy, ±1 count (±0.05%)

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Single +5V supply or 9V battery

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Low-battery annunciator

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User-selectable decimal point placement

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0 to +60°C temperature range

3½ Digit, LCD Display

Low-Cost, Subminiature

Digital Panel Voltmeters

DMS-20LCD Series

Actual Size

(+) 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 ± 2 0 0 mV (-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./BACKLIGH T

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

+5V

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

1

2

3

1

2

4

3

4

®®

www.datel.com

2

DMS-20LCD

3½ DIGIT, LCD DISPLAY DIGITAL PANEL VOLTMETERS

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.

➀

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.

➁

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).

➂

See Technical Notes.

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

DMS-20LCD -1- 5

Accessories:

DMS-20-CP Panel cutout punch
DMS-BZL3 DMS-20 bezel assembly
DMS-BZL4 DMS-20 bezel assembly with sealing gasket
DMS-EB2 Application/evaluation board with standard

MOLEX connector, decimal point solder pads
and attenuation resistor pads.

Input Range:

0 = ±200mV
1 = ±2V
2 = ±20V
3 = ±200V

Power Source:

5 = +5V
9 = +9V

T echnical 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 specifications.

2. ANALOG COMMON (Pin 10): This pin is connected to an
internal, low-noise, "relative" ground. It is used in certain
differential and "floating" 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 point location pins should be left
open. For 5V-powered models, the decimal location pins are TTL
compatible and may be hard wired as described above or driven
with 5V TTL logic gates.

Ordering Information

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

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 Impedance:

DMS-20LCD-0, -1 100 1000 -- M

Ω

DMS-20LCD-2, -3 0.8 1 -- M

Ω

Overvoltage Protection:

➀

DMS-20LCD-0, -1, -2 -- -- ±100 Volts
DMS-20LCD-3 -- -- ±250 Volts

Common Mode Voltage Range

➁

-- -- ±2 Volts

CMRR (dc to 60Hz) -- 86 -- dB
Control Inputs ➂
Decimal Point Placement (Pins 4-6):

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 samples per second
Accuracy (1 minute warm-up):

DMS-20LCD-0 (VIN = +0.19V) -- ±1 ±2 Counts
DMS-20LCD-1 (VIN = +1.9V) -- ±1 ±2 Counts
DMS-20LCD-2 (VIN = +19V) -- ±2 ±3 Counts
DMS-20LCD-3 (VIN = +190V) -- ±2 ±3 Counts

Zero Reading (VIN = 0 Volts) "–001" "000" "001"
Temperature Drift (0 to +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 +600 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 LCD, 0.37"/9.4mm high
Polarity Indication Autopolarity ("–" for negative VIN)
Overrange Indication "–1__ _" for negative VIN

"1___" for positive VIN

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)

Order on-line at www.datel.com