-..
ANALOG
W DEVICES
FEATURES
Third Generation 12L LSI Design
Multiplexed Seven Segment Output Version
Character Serial BCD Output Version
Balanced Differential Input
Low Power: +5V@0.1 Watts (Converter Only)
Small Size 2" x 2" x 0.4" (51x51x10.2mm)
Wide Operating Temperature Range to Extremes of -40°C
and +100° C Available Upon Special Request
Low Cost:
AD2023
3 DigitDPMModule
AD2023
OBS
- $39/1-9, $28/100s
AD2023/B - $37/1-9, $27/100s
APPLICATIONS
LED, LCD, Beckman, etc. Display, Digital Panel Meters
(DPMs), Particularly Where Available Front Panel Meters
Prohibits Use of Traditional DPMs.
ADC Requirements
GENERAL DESCRIPTION
The AD2023 is a low cost, 3 digit DPM module containing all
the circuitry, except gain adjust pot, to drive three external
display digits. The AD2023, with seven segment output, and
the AD2023/B, with character serial BCD output, enable the
user to drive any type of digital display.
Packaged in a small 2" x 2" x 0.4" module and requiring only
+5V power, the AD2023 and AD2023/B address DPM needs
where available front panel space is limited.
The module, utilizing an 12L LSI design, minimizes component
count. Most of the analog and digital circuitry is implemented
on a single proprietory chip. The design is similar to and is
based on the same 12L device as the highly successful AD2026
DPM. And all of the high AD2026 standards for quality and
reliability are retained.
OLE
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WIDE TEMPERATURE RANGE
Wide temperature range modules, for extreme environment
EXCELLENT PERFORMANCE
The AD2023 measures inputs from -99mV to +999mV with an
an accuracy of 0.1% of reading:!:1 digit. Zero shift is :!:0.5mV
over the full operating temperature range, resulting in the same
performance as a DPM with auto zero. The balanced differen-
tial input rejects common mode voltages up to 200mV, enough
to eliminate most ground loop problems.
Automatic polarity indication is provided by using the MSD
(most significant digit) to indicate negative inputs. With the
AD2023, automatic overrange indication for inputs greater
than +999mV is displayed as J J J and for inputs less than
-99mV, as - - -. The AD2023/B overload indication is BCD
output code 1011 for all digits for inputs greater than +999mV
and 1010 for all digits for inputs less than -99mV.
AD2023 (WITH SEVEN SEGMENT OUTPUT)
The AD2023 can drive a 3 digit LED (light emitting diode)
display. Except for the display which is wired directly to the
segment output pins of the module and a gain pot, all the cir-
cuitry is self contained (an optional offset pot can also be used
if desired). The AD2023 drives any size and type of currently
available LED display (for application assistance see Page 3,
Figure 3).
AD2023/B (WITH BCD OUTPUT)
With appropriate decoder driver, the AD2023/B character
serial BCD output unit can drive a variety of different dis-
plays. . . ie., LED, LCD, BecKman, etc. . Only decoder driver,
gain adjust pot, display and digit drivers when necessary are
needed to complete the DPM.
applications, are available up~n special re~uest. Operating
temperature extremes of -40 C and + 100 C and storage tem-
perature of -55°C and +125°C allow the user to apply the
AD2023 in environments where conventional DPMs cannot
be used. Wide temperature range displays are also currently
available from several v~ndors. (For further information con-
sult factory.)
Information furnished by Analog Devices is believed to be accurate
and reliable. However, no responsibility is assumed by Analog Devices
for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implica-
tion or otherwise under any patent or patent rights of Analog Devices.
Route 1 Industrial Park; P.O. Box 280; Norwood, Mass.02062
Tel: 617/329-4700
TWX:716/394-6577
WestCoast
Mid-West
Texas
213/595-1783
312/894-3300
214/231-5094
SPECIFICATIONS
(typical@+25°Cand+5V dc unless
otherwisenoted)
ANALOGINPUT
. Configuration: Limited bipolar, balanced differential
input.
. Full Scale Input Range: -99mV to +999mV
. Automatic Polarity
. Input Impedance: 100Mil
. BiasCurrent: 1l0nA
. Over Voltage Protection: :!:15V(Inputs to Ground)
AD2023 DISPLAYOUTPUTS
PositiveOverload Indication: J J J
. NegativeRange Overload Indication: - --
. Digit Select Outputs: Supply Voltage, 5.5V (max)
louT' 480mA (max pk)
AD2023/B DATA/DISPLA OUTPUTS
Y
. NegativeIndication: BCD code 1010 during MSD
. PositiveOverload Indication: BCD code 1011 for
all digits
. NegativeOverload Indication: BCDCode 1010 for
all digits
. Output Loading: IOL= 8mA @VOUT~0.5V
IOL=
-40011A@VOUT;;.
2.7V
. Digit Select Outputs: Supply Voltage, 5.5V (max)
lOUT' 100mA (max pk)
ACCURACY
CONVERSIONRATE
. Normal: 4 conversionsper second
. High Speed (H.S.): 48 to 168 conversion per second
CONTROLINPUTS
. Hold (1LSTTL Load). Logic "0" or grounding disables
internal or ef'ternal trigger and last conversion is held.
Logic "I" allowsfor normal operation.
. High Speed: Logic "0" on the Hold pin (18) and connec-
ting the H.S. pin (20) to +5V, the module will convert 48
to 168 times per second.
. Lamp Test - Logic "0" on the Lamp Test pin (15) will
turn all segments on in the positive range only.
GAIN ADJUST
A 5k multiturn pot connected from the gain pin (22)
to ground provides the full scale adjustment. This pot
is user supplied.
.
.
Display Current: 46mA/segment multiplexed
OBS
.
.
.
0.1% reading:tl
digit
.
.
.
COMMON MODE VOLTAGE
:t200m V
.
EXTERNAL ZERO ADJUST (OPTIONAL)
A 10kil pot across the zero terminals and the center
Resolution: ImV
. Linearity: :tl Bit
. TemperatureRangel:
-10°C to +70oC operating
-55°C to +125°C storage
Temperature Coefficient: Gain: 50ppm/C
.
Zero:
1011V/C
(essentially
auto zero)
Warm Up Time to Rated Accuracy: Instantaneous
Settling Time to Rated Accuracy: 0.3 second for full
input voltage swing
Input Offset Voltage: :to.3mV (max)
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WEIGHT
1 ounce (28.4 grams)
ORDERING GUIDE
arm to +5V the user can externally adjust zero offset.
POWERINPUT
. Converter: +5V :t5%, 0.1 watts typ.; 0.16 watts max
. Display: +4.75V to +5.5V @ 1.3 watts typ
SIZE
. Module 2" x 2" x 0.4" (51 x 51 x 10.2mm)
.
.
. AD2023/B: Character serial BCD output
. AC2623: Mounting card with gain and zero adjusts
. AC2625: Mounting card with gain and zero adjusts and
high LEDs
three \12"
PRICE
. AD2023
$39/1-9
$28/100s
$27/100s
. AD2023/B
$37/1-9
.
AD2023:
Multiplexed
seven segment
output
COMMON MODE REJECTION (Ik.Q source imbalance, dc
to 1kHz)
.50dB
. AC2623
$34
. AC2625
$39
subject
1 Guaranteed
Specifications
to change
without
notice.
.
OUTLINE DIMENSIONS
AND PIN CONFIGURATIONS
NOTES:
,. PINS 10, ". 12 AND 15 NOTON
MODELAD2023/B
1--2.0151)
1
Dimensions
shown in inches and (mm).
.i
0.4
110.2)
.
0.O19D-
~
-
SEE OTE
N ,--
10.5)
~
¥
A 02023
1
2
3
4
5
6
7
8
9
10
11
12
DISP. POWER
MSD
NSD
LSD
DISP. GND
A
B
C
D
E
F
G
22
21
20
19
18
17
16
15
14
13
GAIN ADJUST
ZERO ADJUST
H. S.
ZERO ADJUST
HOLD
ANALOG HI
ANALOG LO
LAMP TEST
CONY. POWER
CONY. GND
1
2
3
4
5
6
7
8
9
A
B
C
D
AO2023/B
DISP. POWER
MSD
NSD
LSD
DlSP.GND
BCD
OUTPUTS
22
21
20
19
18
17
16
14
13
GAIN ADJUST
ZERO ADJUST
H. S.
ZERO ADJUST
HOLD
ANALOG HI
ANALOG LO
CONY. POWER
CONY. GND
m
-
1
0.2015.1\
0.2516.1)
2.0
151)
PIN 22 REF
PIN 1 REF
BOTTOM
VIEW
SEGMENT
OUTPUTS
}
}
--II--
0.1 GRID TYP
12.5)
-2-
---
Applying AD2023
the
3J
MSD
i) ~6~~~Y
"2
AD202J
DECODER
DRIVER DR
AD202J!B
BCD DRIVERS
SEVEN
SEGMENT
OBS
HIGH SPEED (H.SI(2
OUTPUT
AO202J
ONLY
MOUNTING CARDS
To make AD2023 evaluation easy, two accessory mounting
cards are available. Both are
4Y2"x4"
(114.3x101.6mm) printed
circuit cards. One comes equipped with gain and zero adjust
pots and is suitable for use with the AD2023 or AD2023/B.
The other also includes
Y2"high
LED display and is used with
the AD2023. 3.4 square inches of breadboarding area is also
provided on the two accessory cards. Interconnect is via
standard 44 pin card edge connector.
APPLYING THE AD2023
Description of Operation
The AD2023 and AD2023/B Block Diagram is shown in Fig-
ure 1. The two versions are functionally identic.al except at
the data output section. In the AD2023 the 4 BCD lines from
the 12L Chip are fed into a Decoder Driver and presented on
pins 6 through 12 in seven segment output form for use with
LED displays. The BCD lines in the AD2023/B model are pro-
cessed through BCD Drivers and are presented on pins 6
through 9 in a Character Serial BCD format.
OLE
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Figure
1.
Block Diagram
OPTIONAL CURRENT
LIMITING RESISTORS
FOR BRIGHTNESS ADJUSTMENTS
The Timing Diagram, Figure 2, shows that the Hold input may
be used as a psuedo-trigger provided the trigger pulse is >Sms
(insures at least 1 conversion). A conversion can only be ini-
tiated when all three digit lines are low and the Hold line is
high. As shown, the sequence of digits is MSD, LSD, and NSD.
Led Dispaly DPM
The total requirement to construct a LED display DPM using
the AD2023 is shown in Figure 3.
ANAHI
ANALO
SEVEN
SEGMENT
OUTPUT
AO2023
G
A
I
N
DIGIT
SELECT
{
{
A
B
C
0
E
F
G
/
,
L
I
DIGIT
1
MSD
MSD
NSD
LSD
DIGIT
2
NSD
DIGIT
3
LSD
Signal input, user supplied Gain adjust and optional Zero ad-
just connections are applied directly to the chip. Hold, High
Speed conversion and Lamp Test are implemented via Control
Logic circuitry.
Most of the Analog to Digital conversion takes place within
the chip which feeds Character Serial data to a seven segment
decoder driver (AD2023) or BCD line drivers (AD2023/B).
The appropriate digit is identified via three digit select lines.
Figure
3.
AD2023 with LED Interface
LCD Display DPM
Construction of LCD display DPM requires only an AD2023,
LCD driver and the LCDs.
+Vs
MSD
NSD
LSD
ANA
HI
ANALO BCD
OU~~~
AD2023/B
G
DIGIT
SELECT
{
A
B
c
0
HOLD
>5m,
'CONVERSION
TAKES PLACE HERE
~
N
MSD
NSD
~
LSD
~
Figure4. AD2023/B with LCD Interface
NOTE: OVERLAP MAY OCCUR BETWEEN DIGITS
Figure
2.
Timing Diagram
-3-
Beckman Display DPM
If a Beckman Gas Discharge Display is desired added compo-
nents are: three displays, one DD700 Decoder Driver and three
High Voltage Anode Drivers.
+5V
ANA HI
BCD
ANA LO DATA
OUTPUT
A
{
B
C
D
AD2023/B
MSD
NSD
LSD
Accessory Cards
As shown in Figures 8 and 9, two cards are available, the
AC2623 with Gain and Zero Pots and the AC2625 with Gain
Pot, Zero Pot and three seven segment LED displays. Both
versions come complete with solder pads, power buss tracks
and other features to allow for easy breadboarding. Right
angle connectors for mounting LEDs perpendicular to the P.C.
board are available and accessory card is laid out to be able to
receive these connectors. Connectors are availabe from Augat
6x51-73-161 and Aries Electronics 34-6823-90.
I
N
N
'<t
U
en
I
00
I'
I'
OBS
Figure
5.
AD2023/B
Input Wiring Connections
I, BIAS
17
-<>
HI
AD2023
16
13
14
HIGH VOLTAGE
ANODE DRIVERS
with Beckman Interface
BCD Output DPM
In some cases the AD2023/B may be the choice even when
LED display is to be used. This permits the AD2023/B BCD
output to drive other devices as well as the display and display
can be used to show converted data directly and/or processed
data. Figure 6 shows a BCD output DPM with LED displays.
It is possible to obtain BCD outputs in this fashion when using
other displays as well.
OLE
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AD2023 OR AD2023/B MODULE
NOT SUPPLIED AS PART OF
ACCESSORY
Figure
8.
AC2623
Figure
6.
AD2023/B with LED/PPInterface
Figure
9.
AC2625
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
A
B
C
D
E
F
H
J
K
L
M
N
P
R
S
T
U
V
W
X
Y
Z
.0-
LO
E
R«I00kn)
COMMON MODE
+5V
Figure
7.
Connect to AD2023 as per above for balanced differential
input as shown. The common mode loop MUST provide a
return path for Bias Currents (11 Bias, 12 Bias) internal to the
AD2023. The resistance (R) of this path must be less than
100kil. CAUTION: Total Common Mode Voltage between
Pins 13 and 16 must not exceed 200mV.
For single ended input, connect Pin 13 to Pin 16.
SPARE
SPARE
HIGHSPEED
ZERO ADJUST
mm'\
MSD
DISPLAYPOWER
ANALOGHIGH
ANALOGLa
LAMPTEST
CONY.POWER
POWERGND.
SEGG
F
E
D (BCDD)
C BCDC)
B (BCDB)
SEG A BCDA
DISPLAYGND.
LSD
NSD
::)
z
0
w
I-
Z
a:
a..
<r;
<4
Figure 10. Accessory Card Pin Connections
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