DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 • Email: firstname.lastname@example.org • Internet: www.datel.com
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 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.
• 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
• 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
3½ Digit, LCD Display
Digital Panel Voltmeters
(+) INPUT HI
(–) INPUT LO
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.
Used on backlit models only.
N.C. for non-backlit models.
Only used on ±200mV (-0) and ±2V (-1) models.