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
ALD [ ADVANCED LINEAR DEVICES ]
