A
DVANCED
L
INEAR
D
EVICES,
I
NC.
ALD2321A/ALD2321B/ALD2321
ULTRA LOW VOS EPAD
®
DUAL CMOS ANALOG VOLTAGE COMPARATOR
GENERAL DESCRIPTION
The ALD2321A/ALD2321B/ALD2321 is a monolithic Precision Dual Volt-
age Comparator, each having integrated dual complementary output
drivers. It is constructed using advanced silicon gate CMOS technology.
Key features of the ALD2321A/ALD2321B/ALD2321 include very high
input impedance, very low offset voltage utilizing on-chip e-trim (EPAD
®
electronic-trimming) technology, flexible multiple output configurations and
fast response time with small overdrive voltage. It is designed for ultra low
level signal detection from high impedance sources. For many applications
the ALD2321A/ALD2321B/ALD2321 can eliminate an input amplification
stage, a precision input bias stage, a signal level shift stage and an output
buffer stage, and do the entire job from low level input signal detection to high
output driver -- all on a single chip.
The input voltage includes ground, making this voltage comparator ideal for
single supply (+5V) or dual supply (± 5V) powered systems. For dual supply
applications, GND pin is connected to the most negative supply instead of
Ground (0.0V). The negative supply voltage can be at any value between
0.0V and -5V. Each voltage comparator is individually trimmed at the factory
for minimum offset voltage at ground voltage potential, making the ALD2321A/
ALD2321B/ALD2321 at its best offset voltage and ready to compare very
low signal level voltages at or near ground potential. Typically a signal less
than 1mV can be resolved and detected reliably without requiring amplifica-
tion. Sensor or detector signals with signal power as low as 0.004pW (4 x
10
-15
Watt) can be readily detected.
Each voltage comparator has two complementary output pins, one for
Source Output (OUT
H
) and the other for Sink Output (OUT). This dual
complementary output allows maximum circuit design flexibility. The out-
puts can be used as Single-Ended Driver, Multiple WIRED-OR Outputs,
Push-Pull Outputs or Complementary Outputs. The Sink Output can be
used as an open drain output, which has current sink capability of up to
50mA. It can also be connected to an external voltage higher or lower than
V+, which provide level shift of the output swing levels from other than V+
to GND. The Source Output can source up to 2mA and can be used to drive
the base terminal of an external NPN bipolar device or the gate of a N-
channel MOSFET device. Alternatively, the two outputs, Source Output and
ORDERING INFORMATION
(“L” suffix for lead free version)
Operating Temperature Range *
0°C to +70°C
0°C to +70°C
-55°C to +125°C
16-Pin
Small Outline
Package (SOIC)
ALD2321ASCL
ALD2321BSCL
ALD2321SCL
16-Pin
Plastic Dip
Package
ALD2321APCL
ALD2321BPCL
ALD2321PCL
16-Pin
CERDIP
Package
ALD2321ADC
ALD2321BDC
ALD2321DC
FEATURES
•
•
•
•
•
•
•
•
•
•
•
•
•
Ultra low signal power of 4fW detectable
Ultra low offset voltage of max. 0.2mV
Ultra low input bias currents of typ. 0.01pA
Low supply current of 110µA typical
Virtually eliminates source impedance effects
Low operating supply voltage of 4V to 10V
Single (+5V) and dual supply (±5V) operation
High speed for both small and large level
signals 300ns typical for TTL inputs
CMOS, NMOS and TTL compatible
Each comparator has separate push and
pull outputs
High output sink current - typically 50mA
Low supply current spikes
Fanout of 30 TTL loads
APPLICATIONS
•
•
•
•
•
•
•
Dual limit window comparator
Power supply voltage monitor
Photo-detector sensor circuit
Relay or LED driver
Oscillators
Battery operated instruments
Remote signal detection
PIN CONFIGURATION
OUT
1
OUT
1H
-IN
1
+IN
1
GND
VE
11
VE
12
N/C
*
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
+
OUT
2
OUT
2H
-IN
2
+IN
2
VE
21
VE
22
N/C
*
SCL, PCL, DC PACKAGES
*N/C pins are connected internally.
Do not connect externally.
* Contact factory for leaded (non-RoHS) or high temperature versions.
Rev 2.0 ©2010 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, CA 94089-1706 Tel: (408) 747-1155 Fax: (408) 747-1286
www.aldinc.com
GENERAL DESCRIPTION (cont'd)
Sink Output, can be connected together to form a push-pull output
which has the combined output capabilities of both channels.
In the dual complementary output mode, each comparator can be
used to drive separate loads. Due to the complementary nature of
the two outputs, only one output is active at any a given time, except
for a limited crossover time. When OUT (sink output) is active ON,
the OUT pin is sinking current and the OUT
H
pin is OFF and in high
impedance mode. Conversely, if OUT
H
pin is ON and sourcing
current, OUT pin is OFF. To configure push-pull output, simply
connect OUT (sink output) pin to OUT
H
pin.
Since each voltage comparator has its own complementary out-
puts, each comparator can be configured to have a different output
type. For example, one comparator output can be connected as
Open Drain output while the other comparator can be wired as
push-pull output. If used to drive capacitive loads, the output DC
current levels are at a very low level, at essentially leakage current
levels, which can be a power saving feature.
The ALD2321A/ALD2321B/ALD2321 can detect and resolve very
low voltage levels at high speed, with little or no overdrive voltage.
Compared with other voltage comparator devices that require 100
mV overdrive voltages, or multiple stage circuits that include input
preamp, etc., the ALD2321A/ALD2321B/ALD2321 can perform all
input to output functions in one device with minimal delay time and
with as low as a 1mV signal.
The ALD2321A/ALD2321B/ALD2321 is supplied with 4 external e-
trim pins, VE11, VE12, VE21, and VE22. These pins are used for
trimming of the voltage comparator offset voltages at the factory,
and normally should be left open unconnected. However, in some
cases these pins can be used as positive/negative feedback pins,
since these pins have a positive/negative factor on the offset
voltage. For example, see TYPICAL APPLICATIONS section
titled "Voltage Comparator With Output Feedback to Provide
Hysteresis."
In a printed circuit board layout, it is suggested that
these pins, along with no connect (N/C) pins 8 and 9,
be surrounded with ground traces to prevent any
possible crosstalk and noise coupling from other signal
sources.
Although not required for most applications, if neces-
sary, small valued capacitors of approximately 1000pF
can be mounted at these pins to ground to further
reduce noise. For information on customized trimming
under different biasing and power supply conditions,
please contact factory.
BLOCK DIAGRAM
(16) V
+
INVERTING INPUT
-IN
1
(3)
NONINVERTING INPUT
+IN
1
(4)
-
(2) OUT
1H
(1) OUT
1
+
(7) VE
12
(6) VE
11
(5) GND
INVERTING INPUT
-IN
2
(13)
NONINVERTING INPUT
+IN
2
(12)
-
+
(10) VE
22
(11) VE
21
(14) OUT
2H
(15) OUT
2
(8)
N/C
(9)
N/C
ALD2321 PIN IDENTIFICATION
PIN #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
SYMBOL
OUT1
OUT1H
-IN1
+IN1
GND
VE11
VE12
N/C
N/C
VE22
VE21
+IN2
-IN2
OUT2H
OUT2
V+
FUNCTION
COMPARATOR 1 SINK OUTPUT
COMPARATOR 1 SOURCE OUTPUT
COMPARATOR 1 INVERTING INPUT
COMPARATOR 1 NON-INVERTING INPUT
GROUND / V- SUPPLY
- VOS E-Trim COMPARATOR 1
+ VOS E-Trim COMPARATOR 1
No Connect/Do Not connect externally
No Connect/Do Not connect externally
+VOS E-Trim COMPARATOR 2
- VOS E-Trim COMPARATOR 2
COMPARATOR 2 NON-INVERTING INPUT
COMPARATOR 2 INVERTING INPUT
COMPARATOR 2 SOURCE OUTPUT
COMPARATOR 2 SINK OUTPUT
V+ SUPPLY
Advanced Linear Devices
SIGNAL PROPAGATION
OUTPUT
OUTPUT
INPUT
INPUT
-
INPUT
INPUT
-
-
INPUT
INPUT
INPUT
INPUT
OUTPUT
OUTPUT
-
2 of 11
ALD2321A/ALD2321B/ALD2321
ABSOLUTE MAXIMUM RATINGS
Supply voltage, V+
Differential input voltage range
Power dissipation
Operating temperature range PCL, SCL packages
DC package
Storage temperature range
Lead temperature, 10 seconds
OPERATING ELECTRICAL CHARACTERISTICS
TA = 25
°
C V+ = +5V unless otherwise specified
2321A
Parameter
Supply
Voltage
Supply Current
Current
Voltage Gain
Input Offset Voltage
Input Offset Current
1
Input Bias Current
1
Common Mode Input
2
Voltage Range
Low Level Sink
Output Voltage
Low Level Sink
Output Current
High Level Source
Output Voltage
Source Output
Leakage Current
Sink Output
Leakage Current
Response Time
2
+10.6V
+ +0.3V
-0.3V to V
600 mW
0°C to +70°C
-55°C to +125°C
-65°C to +150°C
+260°C
2321B
Max
±5
10
Min
±2
4
110
Typ
Max
±5
10
180
Min
±2
4
2321
Typ
Max
±5
10
110
180
Unit
V
V
µA
Test Conditions
Dual Supply
Single Supply
No Load
Two Comparators
RLOAD
≥
15K
RLOAD
≥
1.5KΩ
Symbol
VS
V+
IS
Min
±2
4
Typ
110
180
AVD
VOS
IOS
IB
VICR
50
150
0.05
0.01
0.01
0.2
20
20
V+ -1.5
50
150
0.2
0.01
0.01
0.5
20
20
V+ -1.5
50
150
0.5
0.01
0.01
1.0
20
20
V+ -1.5
V/mV
mV
pA
pA
V
-0.3
-0.3
-0.3
VOL
0.15
0.4
0.15
0.4
0.15
0.4
V
ISINK = 12mA
VINPUT = 1V Differential
VOL = 1.0 V
SINK OUTPUT ON
ISOURCE = -2mA
SOURCE OUTPUT ON
VOH = 0.0V
SOURCE OUTPUT OFF
VOUT = 5.0 V
SINK OUTPUT OFF
RL = 5.1KΩ, CL = 15pF
5mV Input Step/
0mV Overdrive
RL = 5.1KΩ ,CL =15pF
1mVInput Step/
0mV Overdrive
VINPUT = 0V to 2.5V
V+ = 4V to 5V
IOL
24
50
24
50
24
50
mA
VOH
3.5
4.5
3.5
4.5
3.5
4.5
V
IHL
0.01
1
0.01
1
0.01
1
nA
IL
0.01
20
0.01
20
0.01
20
nA
tRP
1.1
1.1
1.1
µs
tRP
2.4
2.4
2.4
µs
Common Mode
Rejection Ratio
Power Supply
Rejection Ratio
Change of Vos / VExx
CMRR
80
80
80
dB
PSRR
75
75
75
dB
∆V
OS
∆V
E
5
5
5
mV/V
VE pins No Load
Notes:
1
2
Consists of junction leakage currents
Sample test parameter
ALD2321A/ALD2321B/ALD2321
Advanced Linear Devices
3 of 11
TYPICAL PERFORMANCE CHARACTERISTICS
SUPPLY CURRENT vs.TEMPERATURE
200
SUPPLY CURRENT vs. SUPPLY VOLTAGE
200
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
180
160
140
120
100
80
60
-55
-25
0
25
50
V = +5V
No Load
Two Comparators
+
180
160
140
120
100
80
60
40
20
0
No Load
Two Comparators
T
A
= -55
0
C
T
A
= 25
0
C
T
A
= 125
0
C
75
100
125
0
2
4
6
8
10
12
AMBIENT TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
INPUT BIAS CURRENT vs. TEMPERATURE
LOW LEVEL OUTPUT VOLTAGE (V)
1000
0.5
0.4
0.3
0.2
0.1
0.0
-55
LOW LEVEL OUTPUT VOLTAGE
vs. TEMPERATURE
I
SINK = 12mA
V
INPUT =
1V
Differential
V
+
= +3.5V
INPUT BIAS CURRENT (pA)
V
+
= +5V
100
10
V = +5V
+
1
V
+
= +10V
0
-55
-25
0
25
50
75
100
125
-25
0
25
50
75
100
125
AMBIENT TEMPERATURE (
0
C)
AMBIENT TEMPERATURE (°C)
SATURATION VOLTAGE vs. SINK CURRENT
OUTPUT SATURATION VOLTAGE (V)
HIGH LEVEL OUTPUT VOLTAGE vs. HIGH
LEVEL OUTPUT LEAKAGE CURRENT
HIGH LEVEL OUTPUT CURRENT (nA)
100.0
V
OH
= V
+
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0
15
30
45
T
A
= -55
0
C
60
75
V = +5V
+
T
A
= 125
0
C
T
A
= 85
0
C
T
A
= 25
0
C
T
A
= 125
0
C
10.0
1.0
T
A
= 85
0
C
T
A
= -25
0
C
0.1
T
A
= 25
0
C
0.0
3
4
5
6
7
8
9
10
11
HIGH LEVEL OUTPUT VOLTAGE (V)
OUTPUT SINK CURRENT (mA)
ALD2321A/ALD2321B/ALD2321
Advanced Linear Devices
4 of 11
TYPICAL PERFORMANCE CHARACTERISTICS (cont'd)
HIGH LEVEL OUTPUT VOLTAGE vs.
TEMPERATURE
HIGH LEVEL OUTPUT VOTAGE (V)
10.0
INPUT OFFSET VOLTAGE vs. TEMPERATURE
INPUT OFFSET VOLTAGE (mV)
2.0
1.6
1.2
0.8
0.4
0.0
-0.4
-0.8
-1.2
-1.6
-2.0
V = +5V
+
R
L
= 5.1KΩ
8.0
6.0
V
+
= +10V
I
OH
= -2mA
V = +2.5V
+
V
+
= +5V
4.0
2.0
0.0
-55
-25
0
25
50
75
100
125
V
+
= +4V
-55
-25
0
25
50
75
100
125
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
COMMON MODE REJECTION RATIO
vs. TEMPERATURE
COMMON MODE REJECTION MODE
(dB)
90.0
85.0
80.0
75.0
70.0
65.0
V = +5V
R
L
= 5.1KΩ
+
RESPONSE TIME FOR VARIOUS INPUT
OVERDRIVES
6.0
OUTPUT VOLTAGE
(V)
R
L
= 5.1KΩ
50mV
20mV
C
L
= 15pF
Input Step
5.0
4.0
3.0
2.0
1.0
0.0
10mV
5mV 2mV
1mV
60.0
-55
-25
0
25
50
75
100
125
V
+
= +5V
T
A
= 25
0
C
-1.0
0.0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0
TIME (µS)
AMBIENT TEMPERATURE (°C)
POWER SUPPLY REJECTION RATIO
(dB)
RESPONSE TIME FOR VARIOUS INPUT
OVERDRIVES
6.0
5.0
OUTPUT VOLTAGE
(V)
POWER SUPPLY REJECTION RATIO
vs.TEMPERATURE
90.0
85.0
80.0
75.0
70.0
65.0
60.0
-55
-25
0
25
50
75
100
AMBIENT TEMPERATURE (
0
C)
125
V
+
= +5V
R
L
= 5.1KΩ
1mV
4.0
3.0
2.0
1.0
50mV
0.0
-1.0
0.0 0.3 0.6 0.9
1.2 1.5 1.8
TIME (µS)
2.1 2.4 2.7
3.0
20mV
10mV
2mV
V = +5V T
A
= 25
0
C
+
5mV
R
L
= 5.1KΩ
C
L
= 15pF
Input Step
ALD2321A/ALD2321B/ALD2321
Advanced Linear Devices
5 of 11
