A
DVANCED
L
INEAR
D
EVICES,
I
NC.
ORDERING INFORMATION
* Contact factory for industrial temperature range
© 2008 Advanced Linear Devices, Inc. 415 T asman Drive, Sunnyvale, California 94089 -1706 T el: (408) 747-1 155 Fax: (408) 747-1286 http://www .aldinc.com
GENERAL DESCRIPTION
The ALD2331A/ ALD2331B/ ALD2331 is a monolithic high performance
dual precision voltage comparator built with advanced silicon gate
EPAD® CMOS technology intended for high precision analog applica-
tions. The ALD2331A/ALD2331B/ALD2331 offers ultra-low input
offset voltages and currents at its input pre-amplifier, precision
voltage comparator and high-current output driver integrated on-chip,
in one industry standard pinout 8 Lead PDIP or SOIC package.
Primary features include: very high typical input impedance of 1012 Ω;
low input bias current of 10pA; fast response time of 750ns with only
10mV input step signal; very low power dissipation of 55µA per
comparator; and single +5V or dual ±5V power supply operation; and 50
mA open drain output drivers.
The input voltage range includes ground, making this comparator ideal
for low level signal detection with high source impedance. The outputs
are open-drain configurations, allowing maximum application flexibility,
such as wired-OR connection and various different output loads. An
external pull-up resistor is required for each output, although the value
of the pull-up resistor can vary over a wide range in order to suit the
application needs. The outputs can be connected to a higher external
voltage than V+.
ALD2331A/ALD2331B/ALD2331
DUAL PRECISION CMOS VOLTAGE COMPARATOR
WITH OPEN DRAIN OUTPUT DRIVER
PIN CONFIGURATION
BLOCK DIAGRAM
(1) OUT
1
(7) OUT
2
(4) GND
V
+
NONINVERTING INPUT
+IN
1
(3)
INVERTING INPUT
-IN
2
(6)
NONINVERTING INPUT
+IN
2
(5)
INVERTING INPUT
-IN
1
(2)
(8) V
+
Operating Temperature Range *
0°C to +70°C0°C to +70°C
8-Pin Small Outline 8-Pin Plastic Dip
Package (SOIC) Package
ALD2331A SAL ALD2331A PAL
ALD2331B SAL ALD2331B PAL
ALD2331 SAL ALD2331 PAL
APPLICATIONS
• High source impedance voltage
comparison circuits
• MOSFET driver
• Dual limit window comparator
• Power supply voltage monitor
• Photo-detector sensor circuit
• Relay or LED driver
• Oscillators
• Battery operated instruments
• Remote signal detection
BENEFITS
• Simple precision reference voltage setting
• On-chip input pre-amplifier and output buffers
• Precision voltage comparison without pre-
amplifier
• Eliminate need for second power supply
• Wide range of pull-up resistor values
PRODUCT FEATURES
• Fanout of 30 LS TTL loads
• Guaranteed to drive 200Ω loads
• Low supply current of 55µA typical
• Pinout of LM193 industry standard voltage
comparators
• Extremely low input bias currents-10pA typical
• Virtually eliminates source impedance effects
• Low operating supply voltage of 3V to 10.6V
• Single +5V and dual supply ±5V operation
• High speed for both large and small level
signals -- 300ns typical for TTL inputs
• CMOS, NMOS and TTL compatible
• Wired-OR open drain outputs
• High output sink current - typically 50mA
• Low supply current spikes
1
2
3
4
8
7
6
5
OUT
1
-IN
1
+IN
1
GND
V
+
OUT
2
-IN
2
+IN
2
TOP VIEW
PAL, SAL PACKAGE
Advanced Linear Devices ALD2331A/ALD2331B
ALD2331
ABSOLUTE MAXIMUM RATINGS
Supply voltage, V+ +10.6V
Differential input voltage range -0.3V to V+ +0.3V
Power dissipation 600 mW
Operating temperature range PAL, SAL package 0°C to +70°C
Storage temperature range -65°C to +150°C
Lead temperature, 10 seconds +260°C
OPERATING ELECTRICAL CHARACTERISTICS
TA = 25°C V+ = +5V unless otherwise specified
Supply Voltage V+ 3 10 3 10 3 10 V
Supply Current IS 110 180 110 180 110 180 µA No Load
Two Comparators
Voltage Gain AVD 50 150 50 150 50 150 V/mV RLOAD ≥ 15K
Input Offset Voltage VOS 0.2 0.5 0.5 1.0 1.0 2.0 mV RLOAD ≥ 1.5KΩ
Input Offset Current1IOS 0.01 20 0.01 20 0.01 20 pA
Input Bias Current1 IB 0.01 20 0.01 20 0.01 20 pA
Common Mode Input VICR -0.3 V+ -1.5 -0.3 V+ -1.5 -0.3 V+ -1.5 V
Voltage Range2
Low Level Sink VOL 0.15 0.4 0.15 0.4 0.15 0.4 V ISINK = 12mA
Output Voltage VINPUT = 1V Differential
Low Level Sink IOL 24 50 24 50 24 50 mA VOL = 1.0 V
Output Current SINK OUTPUT ON
High Level Sink Output IL 0.01 20 0.01 20 0.01 20 nA VOUT = 5.0 V
Leakae Curret SINK OUTPUT OFF
Response Time2tRP 1.1 1.1 1.1 µs RL = 5.1KΩ, CL = 15pF
5mV Input Step/
5mV Overdrive
tRP 2.4 2.4 2.4 µs RL = 5.1KΩ ,CL =15pF
1mVInput Step/
1mV Overdrive
tRP 600 600 600 ns RL = 5.1KΩ, CL = 15pF
100mV Input Step/
5mV Overdrive
tRP 300 300 300 ns RL = 5.1KΩ ,CL =15pF
TTL level Input Step
Common Mode CMRR 80 80 80 dB VINPUT = 0V to 2.5V
Rejection Ratio
Power Supply Rejection PSRR 75 75 75 dB V+ = 4V to 5V
Ratio
2331A 2331B 2331
Parameter Symbol Min Typ Max Min Typ Max Min Typ Max Unit Test Conditions
Notes: 1 Consists of junction leakage currents
2 Sample test parameter
Advanced Linear Devices ALD2331A/ALD2331B
ALD2331
SUPPLY CURRENT vs. SUPPLY VOLTAGE
012
200
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
0
108624
20
40
60
80
100
120
140
160
180 No Load
Two Comparators
T
A
= 25
0
C
T
A
= 125
0
C
T
A
= -55
0
C
-55 -25 0 25 50 75 100 125
0
1
10
100
1000
V+ = +5V
INPUT BIAS CURRENT vs. TEMPERATURE
AMBIENT TEMPERATURE (0C)
INPUT BIAS CURRENT (pA)
LOW LEVEL OUTPUT VOLTAGE 
vs. TEMPERATURE
0.5
0.4
0.3
0.2
0.1
0.0
LOW LEVEL OUTPUT VOLTAGE (V)
AMBIENT TEMPERATURE (°C)
-55 -25 025 50 125
100
75
V
+
= +3.5V
V
+
= +5V
V
+
= +10V
I
SINK = 12mA
V
INPUT =
1V 
Differential
SUPPLY CURRENT vs.TEMPERATURE
SUPPLY CURRENT (µA)
AMBIENT TEMPERATURE (°C)
-55 -25 025 50 12510075
160
140
120
100
60
80
180
200
V+ = +5V
No Load
Two Comparators
TYPICAL PERFORMANCE CHARACTERISTICS
COMMON - MODE VOLTAGE REFERRED
TO SUPPLY VOLTAGE
TEMPERATURE (°C)
0.5
V+
-0.5
-1.0
0.5
V-
-0.5
COMMON - MODE VOLTAGE LIMITS (V)
-55 -25 0 25 50 12510075
≈≈
V
S
= ± 2.5 V
TRANSFER FUNCTION
DIFFERENTIAL INPUT VOLTAGE (mV)
+5.0
-5.0
0.0
OUTPUT VOLTAGE (V)
+2.5
0.0
-2.5
T
A
= 25°C
Advanced Linear Devices ALD2331A/ALD2331B
ALD2331
COMMON MODE REJECTION RATIO
vs. TEMPERATURE
COMMON MODE REJECTION MODE 
(dB)
-55 -25 025 50 12510075
85.0
80.0
75.0
70.0
90.0
65.0
60.0
AMBIENT TEMPERATURE (°C)
V
+
= +5V
R
L
= 5.1KΩ
POWER SUPPLY REJECTION RATIO 
vs.TEMPERATURE
AMBIENT TEMPERATURE (
0
C)
-55 -25 0 25 50 100 12575
90.0
85.0
70.0
POWER SUPPLY REJECTION RATIO 
(dB)
80.0
75.0
65.0
60.0
V
+
= +5V
R
L
= 5.1KΩ
INPUT OFFSET VOLTAGE vs. TEMPERATURE
0.4
0.0
-0.4
0.8
-0.8
-1.2
1.2
-2.0
INPUT OFFSET VOLTAGE (mV)
-55 -25 0 25 50 12510075
AMBIENT TEMPERATURE (°C)
-1.6
2.0
1.6 R
L
= 5.1KΩ
V
+
= +5V
V
+
= +2.5V
0.0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0
-1.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
RESPONSE TIME FOR VARIOUS INPUT 
 OVERDRIVES
OUTPUT VOLTAGE
(V)
TIME (µS)
50mV
20mV
10mV
5mV 2mV 1mV
V
+
= +5V
R
L
= 5.1KΩInput StepC
L
= 15pF
T
A
= 25
0
C
TYPICAL PERFORMANCE CHARACTERISTICS
SATURATION VOLTAGE vs. SINK CURRENT
OUTPUT SINK CURRENT (mA)
015 30 45 60 75
OUTPUT SATURATION VOLTAGE (V)
3.0
2.0
1.0
0.0
2.5
1.5
0.5
V+ = +5V TA = 1250C
TA = -550C
TA = 850C
TA = 250C
TA = -250C
OUTPUT OFF-STATE VOLTAGE vs.
OUTPUT LEAKAGE CURRENT
34567891011
0.0
0.1
1.0
10.0
100.0 VOH = V+
OUTPUT LEAKAGE CURRENT (nA)
OUTPUT OFF-STATE VOLTAGE (V)
TA = 1250C
TA = 850C
TA = 250C
Advanced Linear Devices ALD2331A/ALD2331B
ALD2331
+
-
+5V
V
A
= 0V to +10V
+10V
0
V
OUT
V
IN+
V
IN-
V
OUT
VOLTAGE COMPARATOR WITH SINGLE
SUPPLY AND OUTPUT LEVEL SHIFT
VOLTAGE COMPARATOR
WITH +/-5V SUPPLY AND +5V RELAY DRIVE
PRECISION SINGLE SUPPLY VOLTAGE
COMPARATOR WITH DIRECT RELAY DRIVER
6810 12
4
2SUPPLY VOLTAGE (V)
OUTPUT LOW VOLTAGE
vs. SUPPLY VOLTAGE
OUTPUT LOW VOLTAGE (V)
T
A
= 25°C
I
OL
= 12mA
0.0
0.2
0.4
0.5
0.6
0.1
0.3
TYPICAL APPLICATIONS
+5
5V
RELAY
+
-
+5
V
IN
V
R
+
-
5V
RELAY
-5
+5
V
IN+
1K
V
IN-
-
-
+
+
Q
Q
V
IN
V
REF
V+
VOLTAGE COMPARATOR WITH
COMPLEMENTARY OUTPUTS
TYPICAL PERFORMANCE CHARACTERISTICS
RESPONSE TIME FOR VARIOUS INPUT 
 OVERDRIVES
OUTPUT VOLTAGE
(V)
-1.0
6.0
2.0
0.0
1.0
3.0
4.0
5.0
0.0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0
TIME (µS)
T
A
= 25
0
C
V
+
= +5V
1mV
2mV
5mV
10mV
20mV
50mV
R
L
= 5.1KΩ
C
L
= 15pF
Input Step
Advanced Linear Devices ALD2331A/ALD2331B
ALD2331
TYPICAL APPLICATIONS
VOLTAGE COMPARATOR WITH OUTPUT LEVEL
SHIFT AND HIGH CURRENT LOAD DRIVER
VOLTAGE COMPARATOR WITH +/-5V
SUPPLY AND OUTPUT LEVEL SHIFT
+
-
15K
-5V
+5V
V
OUT
15K
100K
100K
0.1µF
0.1µF
+5V
0
V
OUT
+5V
+
-
-5V
+5V
R
2
=50 200Ω
+5V
R
1
= 15K
R
Load
V
OUT
V
IN+
V
IN-
0.066V
-4V
V
OUT
RESPONSE TIME MEASUREMENT CIRCUIT
Response time is defined as the internal between the applica-
tion of an input step function and the instant when the output
reaches 50% of its maximum value as measured by the
following test circuit:
+
-
5.1KΩ
OUT
+5V
10X INPUT STEP
1KΩ
9KΩ
V
IN
DUAL LIMIT WINDOW COMPARATOR
+
+
-
-
OUTPUT HIGH FOR V
IN
<
V
REF(HIGH)
MINIMUM R
LOAD
= 1.5KΩ
> AND
V
OUT
V
IN
V+
V
REF(HIGH)
V
REF(LOW)
V
REF(LOW)
R
LOAD
N
DUAL LIMIT PHOTO DETECTOR MONITOR
V+
V
LIMIT2
PHOTO-
DETECTOR
LIGHT
-
-
+
+
LED
BUZZER
V
LIMIT 1
V
External
LED turns on as photo-detector
voltage reaches VLIMIT1.
Both LED and horn turns on as photo-
detector voltage reaches VLIMIT2.
VEXTERNAL= +10V, V+ = +5V