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
Voltage 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 1 mV can be resolved and
detected reliably without requiring amplification. Sensor or detector
signals with signal power as low as 0.004 pW(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
outputs 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 50 mA. 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.
ORDERING INFORMATION
Operating Temperature Range*
0°C to +70°C
16-pin
Small Outline Package
(SOIC)
ALD2321ASC
ALD2321BSC
ALD2321SC
0°C to +70°C
16-Pin
Plastic DIP Package
(PDIP)
ALD2321APC
ALD2321BPC
ALD2321PC
-55°C to +125°C
16-Pin
Ceramic DIP Package
(CDIP)
ALD2321ADC
ALD2321BDC
ALD2321DC
PRODUCT FEATURES
* Ultra low signal power of 4 fW detectable
* Ultra low offset voltage of max. 0.2 mV
* Ultra low input bias currents of typ. 0.01pA
* Low supply current of 110
µA
typical
* Virtually eliminates source impedance effects
* Low operating supply voltage of 3V 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
* Low level signal detector
* 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
*
DC, PC, SC PACKAGE
*
*N/C pins are connected internally. Do not connect externally.
* Contact factory for industrial temperature range
© 2004 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, California 94089 -1706 Tel: (408) 747-1155 Fax: (408) 747-1286 http://www.aldinc.com
GENERAL DESCRIPTION (cont'd)
The Source Output can source up to 2 mA 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 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. Con-
versely, 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
outputs, 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
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
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 TYPI-
CAL APPLICATIONS section titled "Voltage Comparator
With Output Feedback to Provide Hysteresis."
In 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 necessary,
small valued capacitors of approximately 1000 pF 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
SIGNAL PROPAGATION
OUTPUT
OUTPUT
INPUT
INPUT
-
INPUT
INPUT
-
-
INPUT
INPUT
INPUT
INPUT
OUTPUT
OUTPUT
-
2
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
ALD2321A/ALD2321B
ALD2321
ABSOLUTE MAXIMUM RATINGS
Supply voltage, V+
Differential input voltage range
Power dissipation
Operating temperature range PC, SC package
DC package
Storage temperature range
Lead temperature, 10 seconds
+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
OPERATING ELECTRICAL CHARACTERISTICS
TA = 25
°
C V+ = +5V unless otherwise specified
2321A
Parameter
Supply Voltage
Supply Current
Symbol
V+
IS
Min
3
110
Typ
Max
10
180
Min
3
110
2321B
Typ
Max
10
180
Min
3
110
2321
Typ
Max
10
180
Unit
V
µA
No Load
Two Comparators
RLOAD
≥
15K
RLOAD
≥
1.5KΩ
Test Conditions
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
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, C L = 15pF
5mV Input Step/
0mV Overdrive
RL = 5.1KΩ ,C L =15pF
1mVInput Step/
0mV Overdrive
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
Notes:
1
2
CMRR
80
80
80
dB
VINPUT = 0V to 2.5V
V+ = 4V to 5V
PSRR
75
75
75
dB
∆V
OS
∆V
E
5
5
5
mV/V
VE pins No Load
Consists of junction leakage currents
Sample test parameter
ALD2321A/ALD2321B
ALD2321
Advanced Linear Devices
3
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
1000
LOW LEVEL OUTPUT VOLTAGE
vs. TEMPERATURE
LOW LEVEL OUTPUT VOLTAGE (V)
0.5
0.4
0.3
0.2
0.1
0.0
-55
-25
0
25
50
75
100
125
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
0
100
125
AMBIENT TEMPERATURE ( 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
HIGH LEVEL OUTPUT VOLTAGE (V)
11
OUTPUT SINK CURRENT (mA)
ALD2321A/ALD2321B
ALD2321
Advanced Linear Devices
4
TYPICAL PERFORMANCE CHARACTERISTICS
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)
RESPONSE TIME FOR VARIOUS INPUT
OVERDRIVES
6.0
OUTPUT VOLTAGE
(V)
90.0
85.0
80.0
75.0
70.0
65.0
V = +5V
R
L
= 5.1KΩ
+
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)
RESPONSE TIME FOR VARIOUS INPUT
OVERDRIVES
6.0
5.0
OUTPUT VOLTAGE
(V)
POWER SUPPLY REJECTION RATIO
(dB)
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
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