DATEL, Inc., Mansfield, MA 02048 (USA)
Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356
Email: sales@datel.com
Internet: www.datel.com
Figure 1. DMS-30LCD Series Simplified Schematic
DMS-30LCD Series
3 Digit, LCD Display
Low-Power, Miniature
Digital Panel Voltmeters
Features
Large (0.4"/10.2mm), enhanced-
contrast, LCD display
Single +5V supply or 9V battery
Power as low as 3.2mW
Miniature size:
2.17" x 0.92" x 0.43"
55mm x 23mm x 11mm
Epoxy-encapsulated, 12-pin DIP
Backlit displays optional
4 differential input voltage ranges
High accuracy, 1 count (0.05%)
Autopolarity changeover and overrange
indication
User-selectable decimal point placement
Numerous "plug-on" application boards
0 to +60C temperature range
Offering all the outstanding features and benefits of DATEL's industry leading
DMS-20LCD Series of 3 Digit LCD Panel Meters, DMS-30LCD meters offer larger,
more easily readable displays at slightly higher power consumptions. Like all DMS
Series LCD meters, these miniature (2.17" x 0.92" x 0.43"), epoxy-encapsulated
devices offer component-like ease-of-use, outstanding reliability and easy installation
in either panels or pc-cards.
DMS-30LCD devices operate from a single +5V supply or a 9V battery. Battery-
operated units typically draw 350A and consume a mere 3.2mW. Backlit models are
available for low-light applications; though we have found many designers prefer
DATEL's unique low-power LED meters in those circumstances.
Offering 4 optional input voltage ranges (200mV, 2V, 20V or 200V), DMS-
30LCD meters have an extremely user-friendly input structure. They can be used in
differential or single-ended modes. Input impedance is a minimum 800k
. CMRR is
typically 86dB. CMV is 2V, and inputs are overvoltage protected to 100V.
Each meter incorporates an extremely stable, double regulated reference and is
fully calibrated at our factory prior to encapsulation. We guarantee outstanding initial
accuracy (1 count) and excellent stability over temperature (0.15 counts/C).
These extremely rugged meters are moisture and vibration proof and never require
adjustment or recalibration.
For popular applications (4-to-20mA, rms-to-dc conversion, ac line power, J and K
thermocouples, etc.), the DMS-30LCD Series includes a complete line of "plug-on"
application boards that conveniently convert your meter into an application-specific
instrument.
Actual Size
+1.23V REFERENCE OUT
(+) 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
+5V
1.23V
REF.
R2
+2.0V
DATA
909k
V+
V
A/D
CONVERTER
0 Vdc
0.01F
1
DISPLAY TEST/
BACKLIGHT
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.
J1
DC/DC converter is not used on 9V-powered models,
J1 is connected.
Display Test function is not available on backlit models.
1.82k
3
2
1
3
2
www.datel.com
2
Analog Inputs
Min.
Typ.
Max.
Units
Full Scale Input Range:
DMS-30LCD-0
--
200
--
mV
DMS-30LCD-1
--
2
--
Volts
DMS-30LCD-2
--
20
--
Volts
DMS-30LCD-3
--
200
--
Volts
Input Impedance:
DMS-30LCD-0, -1
100
1000
--
M
DMS-30LCD-2, -3
0.8
1
--
M
Overvoltage Protection
DMS-30LCD-0, -1, -2
--
--
100
Volts
DMS-30LCD-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)
Display Test
(Pin 2)
Tie to pin 1 to activate
Backlight
(Pin 2)
Tie to pin 3 to turn on backlight
Performance
Sampling Rate
2.5 samples per second
Accuracy
(1 minute warm-up):
DMS-30LCD-0 (V
IN
= +0.19)
--
1
2
Counts
DMS-30LCD-1 (V
IN
= +1.9V)
--
1
2
Counts
DMS-30LCD-2 (V
IN
= +19V)
--
2
3
Counts
DMS-30LCD-3 (V
IN
= +190V)
--
2
3
Counts
Zero Reading
(V
IN
= 0 Volts)
" 001"
"000"
"001"
Temperature Drift
(0 to +60C)
--
0.15
0.3
Cnts/C
+1.23V Reference Out
(Pin 9)
+1.20
+1.23
+1.25
Volts
Power Supply Requirements (5V Models)
Supply Voltage
+4.75
+5.00
+5.25
Volts
Supply Current:
Standard Models
--
800
1200
A
Backlit Models
--
45
60
mA
Power Supply Requirements (9V Models)
Supply Voltage
+7.5
+9.0
+14.0
Volts
Supply Current:
Standard Models
--
350
600
A
Backlit Models
--
45
60
mA
Display
Display Type and Size
3 Digit LCD, 0.4"/10.2mm high
Polarity Indication
Autopolarity ("" for negative V
IN
)
Overrange Indication
"1_ _ _ " for negative V
IN
"1_ _ _ " for positive V
IN
Physical/Environmental
Operating Temperature
0
--
+60
C
Storage Temperature
20
--
+75
C
Humidity
(Non-condensing)
0
--
95
%
Case Material
Polycarbonate
Weight
0.75 ounces (21 grams)
DMS-30LCD
Performance/Functional Specifications
Typical at T
A
= +25C and supply voltage = +5V (using the single-ended input circuit) or +9V
(using the differential input circuit), unless otherwise noted.
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.
DMS-30LCD - 1 - 5
Input Range:
0
= 200mV
1
= 2V
2
= 20V
3
= 200V
Accessories:
DMS-30-CP
Panel cutout punch
DMS-BZL1
DMS-30 bezel assembly
DMS-BZL2
DMS-30 bezel assembly with sealing gasket
RN-DMS
Gain/offset potentiometer kit for DMS-EB,
DMS-EB-AC/DC and DMS-EB-DC/DC
DMS-PS1-CM
+5V/1.0A AC/DC power supply module
Add-On Application Boards:
DMS-EB
Multi-purpose (gain/offset, 4-20mA, etc.)
DMS-EB-HTB
High-accuracy temperature probe sensing for
200mV models
DMS-EB-DC/DC
Provides isolated +5V power
DMS-EB-TCJ
J-type thermocouple inputs for 2V models
DMS-EB-TCK
K-type thermocouple inputs for 2V models
DMS-EB-RMS
For true rms measurements of ac voltages
DMS-EB-AC/DC
For ac line-powered applications
DMS-EB-LP
For 4-to-20mA loop-powered applications
Leave blank for standard
models.
Add
B
for backlit models.
Power Source:
5
= +5V
9
= +9V
Technical Notes
1. +1.23V REFERENCE OUTPUT (Pin 9):
This pin is the output of
the meter's precision +1.23V internal reference, and it is referenced
to ANALOG COMMON (pin 10) which sits at a potential of
approximately +2V. This output should be buffered if used to drive
external loads since sourcing more than 15A from pin 9 can affect
both the initial accuracy and temperature drift of the meter.
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 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
Ordering Information
A panel-mount retaining clip is supplied with each model.
Order on-line at www.datel.com
3
3 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
DMS-30LCD
Applications
Figure 2. Single-Ended Input Configuration
(5V-Powered Models)
Example: If +BATTERY (pin 1 with respect to pin 3) is +12.6V,
R
Series
= Ohms
+12.6 9.2V
0.035
R
Series
= Ohms
+BATTERY 9.2V
0.035
R
Series
= 97 Ohms
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.
4. 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.
5. DISPLAY TEST (Pin 2):
(Not available on backlit models)
Connect DISPLAY TEST (pin 2) to +5V SUPPLY/+BATTERY
(pin 1) to activate. All LCD segments, exclusive of the decimal
points, will be momentarily enabled.
Do not leave the unit in
the TEST mode for more than 10 seconds as this will
damage the LCD segments.
6. BACKLIGHT (Pin 2) Function:
For backlit models, grounding
pin 2 (i.e. connecting it to pin 3) turns on the backlighting LED's.
9V-powered backlit models function with supply voltages up to
+14V, however, activating the backlight with voltages greater than
9.2V can damage the meter. Therefore, a 1/4 Watt series resistor
must be installed between pins 3 and 2 in these situations. The
value of the series resistor is determined using the following
formula:
In any backlit application, including those with supply voltages
< 9.2V, the current drawn by the backlight (and therefore the
current drawn by the meter) can be reduced by installing a 1/4
Watt resistor between pins 3 and 2. The brightness of the
backlight will be reduced proportionately.
7. Gain Adjust:
There is a gain-adjust potentiometer on the back of
each meter. It has approximately 50 counts (2.5%) of
adjustment range. Since these devices essentially have no zero/
offset errors, a gain adjustment is effectively an overall accuracy
adjustment. Though they may be performed at any point (except
zero), accuracy adjustments are most effective when performed
with higher level input signals. Refer to Figure 9 for applications
requiring greater ( 10%) gain adjustments.
8. Soldering Methods:
All models in the DMS-30LCD Series
easily withstand most common wave soldering operations. We
DMS-30LCD meters are available in either 5V-powered or 9V-
powered models. 9V devices operate directly from 7.5V to 14V
supplies (usually batteries) without the need for external voltage
regulators. 9V devices, however, can not be used to measure
voltages referenced to the negative battery terminal (pin 3) because
the minus input to the meter (pin 12, () INPUT LO) must always be
at least 1.5V above pin 3. 9V-powered meters can only be used to
make differential and not single-ended measurements.
5V-powered devices operate from any well-regulated +5V supply
and will accurately measure voltages both above and below pin 3
(5V RETURN) in either single-ended or differential configurations.
1. Single-Ended Input Configurations:
True single-ended
measurements can only be made with 5V-powered meters.
The circuit of Figure 2 avoids problems normally associated
with ground-loop currents. Separate ground runs should be
used for 5V RETURN (pin 3) and () INPUT LO (pin 12).
recommend, however, you evaluate the effects your particular
soldering techniques may have on the meter's plastic case and
high-precision electrical performance. We recommend the use of
water-soluble solders and thorough cleaning procedures.
9. Suggested Mating Connectors:
Panel mounted:
Connector housing
DATEL P/N 39-2079400
Terminal type
DATEL P/N 39-2099090
Crimping tool
DATEL P/N 39-2099000
Wire size
22 to 26 AWG
Insulation diameter
0.062" (1.57mm) maximum
Stripping length
0.100 to 0.125" (2.54 to 3.17mm)
Board mounted:
Socket
DATEL P/N 39-2359625
1
1 2
3
+ 5 V S U P
( ) I N L O
5 V R E T
D A T E L
D M S - P S 1 - C M
8 5 - 2 6 4 V a c
1 1
( + ) I N H I
6
D P 1
+
A C t o D C C o n v e r t e r
V
I N
D M S - 3 0 L C D - 1 - 5
8
7
R E . O U T
R E . I N
4
4. Floating Signal Source Measurements:
Floating signals can
be measured using the circuits shown in Figures 5 and 6. Figure
5 uses a 5V-powered meter. Figure 6 uses a 9V-powered meter.
Connecting pin 10 (ANALOG COMMON) to () INPUT LO (pin
12) provides the reference point for the meter's input.
A "floating" input is a signal that has no galvanic connection to
the meter's power supply. In the figures below, the 1.5V battery
illustrates a true floating input.
DMS-30LCD
3 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
Figure 3. Differential Input Configuration
(5V-Powered Models)
3. Engineering Scaling:
For measuring voltages greater than the
full scale input range of a given meter, the input signal must be
attenuated. A simple voltage divider (similar to that shown in
Figure 4) will scale the input to within the range of the selected
meter. R1 and R2 should be precision, 1%, metal-film resistors
with absolute TCR's less than 50ppm/C. See Ap Note 4 for more
information on engineering scaling.
R2
R1 + R2
x V
IN
= Reading
50k
< R1 + R2 < 10M
Figure 6. Floating Input Measurements
(9V-Powered Models)
Figure 5. Floating Input Measurements
(5V-Powered Models)
Figure 4. Input Attenuation Circuit
Applications
2. Differential Input Configurations:
Differential measurements
can be made with either 5V-powered or 9V-powered meters.
Figure 3, though not a practical real-world application, uses a
voltage divider to demonstrate the concept of a differential input
signal. Be careful not to exceed the 2V common mode voltage
limitation for 5V-powered meters.
5. Process Control (4-to-20mA) Measurements:
In many
common process-control applications, a 4-to-20mA current loop
is used to transmit information. Because DMS-30LCD meters
have such high input impedance, a simple shunt resistor across
the meter's input can be used to convert the loop current to a
voltage. See Figure 7. The value of the shunt resistor is a
1
1 2
3
+ 5 V S U P
( ) I N L O
5 V R E T
1 1
( + ) I N H I
6
A C t o D C C o n v e r t e r
R 2
R 1
R 3
1 k
1 k
1 k
8
7
R E . I N
D P 1
R E . O U T
D M S - 3 0 L C D - 1 - 5
D A T E L
D M S - P S 1 - C M
8 5 - 2 6 4 V a c
R 2
1 1
1 2
( + ) I N H I
( ) I N L O
V
I N
R 1
+
1
3
+ 5 V S U P
5 V R E T
A C t o D C C o n v e r t e r
8
7
R E . O U T
R E . I N
D M S - 3 0 L C D - 1 - 5
D A T E L
D M S - P S 1 - C M
8 5 - 2 6 4 V a c
1
3
+ 5 V S U P
5 V R E T
6
D P 1
A C t o D C C o n v e r t e r
1 2
( ) I N L O
1 0
A N A C O M M
1 1
( + ) I N H I
1 . 5 V
C E L L
+
8
7
R E . O U T
R E . I N
D M S - 3 0 L C D - 1 - 5
D A T E L
D M S - P S 1 - C M
8 5 - 2 6 4 V a c
1
3
+ BAT
BAT
9V
BATTERY
6
DP1
12
() IN LO
10
ANA COMM
11
(+) IN HI
1.5V
CELL
+
+
8
7
REF OUT
REF IN
DMS-30LCD-1-9
5
3 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
DMS-30LCD
R2
(R1 + R2 + R3)
= 0.1
Figure 7. 4-to-20mA Current Loop Operation
(5V-Powered Models)
Figure 9. External Gain Adjustment
Figure 8. Power Supply Monitor
(9V-Powered Models)
Applications
6. Power Supply Monitoring:
A popular application for DATEL's
low-power LCD meters is monitoring the supply voltage in
battery-operated portable equipment. Figure 8 demonstrates
how a 9V-powered DMS-30LCD can be used to monitor its own
supply. The meter used is the DMS-30LCD-1-9. A three-resistor
voltage divider is used to attenuate the battery voltage and also
to satisfy the requirement that the input voltages applied to pins
12 and 11 be at least 1.5 Volts above and below the battery
voltage applied to pins 1 (+BATTERY) and 3 (BATTERY). The
divider should be designed so that 1/10th the battery voltage falls
across the inputs to the meter:
To calibrate the circuit of Figure 7, perform the following:
1. With 4mA applied, adjust the 50k
potentiometer (R2) to
display a reading of "000" (assuming that is the desired
reading).
2. With 20mA applied, adjust the gain-adjust potentiometer on
the back of the meter to display a reading of "1999". For different
full scale readings, alter the R
Shunt
value accordingly.
function of the scaling requirements of the particular application
and can be calculated using the following equation:
R
Shunt
= R1 = V
Fsr
/ I
Fsr
Where:
V
Fsr
= Full scale reading (in Volts)
I
Fsr
= Relative full scale current (in Amps)
Example: For a meter with a 2V full scale input (1.999 full
scale reading) and a desired full scale display reading of
1000 (with an input of 20mA), V
Fsr
= 1.000 Volts
R
Shunt
= 1.000V/(0.020 0.004)A
R
Shunt
= 1.000V/0.016A = 62.5 Ohms
7. External Gain Adjustment:
Connect REFERENCE OUT
(pin 8) to REFERENCE IN (pin 7) for normal, factory calibrated,
operation. Use the +1.23V REFERENCE OUT (pin 9) for
applications needing external gain adjustment. Figure 9 shows
the wiring configuration for each model. Calibration is performed
with a precise, near-full-scale, input voltage.
Therefore, the 9V battery voltage appears to the meter inputs
as 0.9V. With the decimal point moved to its DP2 position
(pin 5 tied to pin 3), the meter reads 9.00 Volts.
The circuit can be calibrated by first measuring the actual
battery voltage with another meter and then adjusting the gain-
adjust potentiometer on the back of the DMS-30LCD until a
similar reading is obtained. If possible, the resistors in the
divider should be 1% metal-film types with TCR's less than
50ppm/C.
1
3
+ 5 V S U P
5 V R E T
A C t o D C C o n v e r t e r
( ) I N L O
A N A C O M M
( + ) I N H I
R 1
+
4 - 2 0 m A
5 0 k
R 2
8
7
R E . O U T
R E . I N
D M S - 3 0 L C D - 1 - 5
D A T E L
D M S - P S 1 - C M
8 5 - 2 6 4 V a c
1
12
3
+BAT
() IN LO
BAT
11
(+) IN HI
5
DP2
R2
R1
R3
45.3k
10.1k
45.3k
9V
BATTERY
+
8
7
REF OUT
REF IN
DMS-30LCD-1-9
9
(+) IN HI
() IN LO
ANA COMM
10
1.23V REF
1k
10 to 20 Turns
8
REF IN
11
1k
10 to 20 Turns
8.45k, 1%
8.45k, 1%
5V RET
7
NC
12
3
For 5V models tie
() IN LO to pin 3
For 9V models tie
() IN LO to pin 10
12
VOLTAGE
CALIBRATOR
OUT
COM
Connections
for 2V and
20V models
Connections
for 200mV
models
DMS-30LCD
DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
Internet: www.datel.com Email: sales@datel.com
Data sheet fax back: (508) 261-2857
DATEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein
do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.
ISO 9001
ISO 9001
R
E
G
I
S
T
E
R
E
D
DS-0259C 10/01
DATEL (UK) LTD. Tadley, England Tel: (01256)-880444
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01
DATEL GmbH Mnchen, Germany Tel: 89-544334-0
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-354-2025
DMS-30LCD
3 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
MECHANICAL DIMENSIONS: Inches (mm)
TOLERANCES: 2 PL DEC 0.02 (0.51)
3 PL DEC 0.010 (0.254)
LEAD DIMENSIONS: 0.025 (0.635) x 0.025 (0.635) NOMINAL
RECOMMENDED PC BOARD FINISHED HOLE DIAMETER:
0.042 0.003 (1.067 0.076)
Mechanical Specifications
MA
DE IN
USA
BEZEL INSTALLATION
PANEL
BEZEL
#2-56 INSERT
0.156 (3.96) DEEP
FRONT VIEW
1.270
(32.26)
0.187
(4.75)
OPTIONAL BEZEL (DMS-BZL1 and DMS-BZL2)
2.35 (59.69)
2.118 (53.80)
0.093 (2.362) DIAMETER (4 REQUIRED)
ONLY WHEN USING OPTIONAL BEZEL ASSEMBLY
RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS
INTERNAL CORNER RADII:
0.032 (0.81) MAX.
1.07
(27.18)
0.878
(22.30)
0.096
(2.44)
0.116
(2.95)
2.55 (64.77)
PANEL CUTOUT
RETAINING CLIP INSTALLATION
PANEL
MA
DE IN
USA
DM
S-30LCD
-X-
XX
PIN #1
IDENTIFIER
FRONT VIEW
+5V SUPPLY/ +BATTERY
DISPLAY TEST/BACKLIGHT
5V RETURN/ BATTERY
DP3
DP2
DP1
1
2
3
4
5
6
12
11
10
9
8
7
() INPUT LO
(+) INPUT HI
ANALOG COMMON
+1.23V REFERENCE OUT
REFERENCE OUT
REFERENCE IN
DP1
DP2
DP3
2.17
(55.1)
2.09
(53.1)
1.80
(45.7)
0.25 (6.4) TYP.
0.15
(3.7)
TYP.
0.040
(1.02)
0.040
(1.02)
0.10
(2.5)
TYP.
0.50
(12.7)
0.17
(4.3)
TYP.
0.92
(23.4)
0.84
(21.3)
0.430 (10.92) STANDARD
0.560 (14.22) BACKLIT
0.040
(1.02)
0.240
(6.10)
0.260
(6.60)
PIN 1
CALIBRATION POTENTIOMETER HOLE LOCATION
0.125 (3.175) DIAMETER
(USE ONLY WHEN PC BOARD MOUNTING)
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