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

®

®

www.datel.com

Actual Size

DMS-20LCD Series

3½ Digit, LCD Display

Low-Cost, Subminiature

Digital Panel Voltmeters

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), enhancedcontrast 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

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 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.

	1		+5V
+5V SUPPLY/					V+
+BATTERY
				–5V
	2	DC/DC	3
N.C.
		CONVERTER			V–
5V RETURN/	3		J1	A/D
–BATTERY		0 Vdc		CONVERTER
	4		DATA
DP 3
DP 2	5
DP 1	6
1	R2 is not used on ±200mV (-0) models or ±2V (-1) models.				3
	R2 = 100k on ±20V (-2) models and 9.1k on ±200V (-3) models.
2	Only used on ±200mV (-0) and ±2V (-1) models.				4

12

(–) INPUT LO

1

2 R2

0.01µF

R1 11

(+) INPUT HI

909k

≈ +2.0V

10 ANALOG COMMON

9

N.C./BACKLIGHT 4

8

REFERENCE OUT

+5V

7

REFERENCE IN

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

Used on backlit models only.

N.C. for non-backlit models.

Figure 1. DMS-20LCD Series Simplified Schematic

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

DMS-20LCD	3 ½ D I G I T , L C D D I S P L A Y D I G I T A L P A N E L V O L T M E T E R S

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 Impedance:
DMS-20LCD-0, -1	100	1000	--		MΩ
DMS-20LCD-2, -3	0.8	1	--		MΩ
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 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)

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

Input Range:

Leave blank for standard

0

= ±200mV

models.

1

= ±2V

Add B for backlit models.

2

= ±20V

Power Source:

3

= ±200V

5 = +5V

9 = +9V

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.

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

Order on-line at www.datel.com

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 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.

2