DUAL EPAD™ MICROPOWER OPERATIONAL AMPLIFIER
ADVANCED
LINEAR
DEVICES, INC.
ALD2721E/ALD2721
GENERAL DESCRIPTION
The ALD2721E/ALD2721 is a dual monolithic rail-to-rail precision CMOS
operational amplifier with integrated user programmable EPAD (Electri-
cally Programmable Analog Device) based offset voltage adjustment. The
ALD2721E/ALD2721 is a dual version of the ALD1721E/ALD1721 opera-
tional amplifier. Each ALD2721E/ALD2721 operational amplifier features
individual, user-programmable offset voltage trimming resulting in signifi-
cantly enhanced total system performance and user flexibility. EPAD
technology is an exclusive ALD design which has been refined for analog
applications where precision voltage trimming is necessary to achieve a
desired performance. It utilizes CMOS FETs as in-circuit elements for
trimming of offset voltage bias characteristics with the aid of a personal
computer under software control. Once programmed, the set parameters
are stored indefinitely. EPAD offers the circuit designer a convenient and
cost-effective trimming solution for achieving the very highest amplifier/
system performance.
The ALD2721E/ALD2721 dual operational amplifier features rail-to-rail
input and output voltage ranges, tolerance to overvoltage input spikes of
300mV beyond supply rails, capacitive loading up to 50pF, extremely low
input currents of 0.01pA typical, high open loop voltage gain, useful
bandwidth of 700KHz, slew rate of 0.7V/µs, and low typical supply current
of 200µA for both amplifiers.
KEY FEATURES
• EPAD ( Electrically Programmable Analog Device)
• User programmable V
OS
trimmer
• Computer-assisted trimming
• Rail-to-rail input/output
• Compatible with standard EPAD Programmer
• Each amplifier V
OS
can be trimmed to a different Vos level
• High precision through in-system circuit trimming
• Reduces or eliminates V
OS
, PSRR, CMRR and TCV
OS
errors
• System level “calibration” capability
• Application Specific Programming mode
• In-System Programming mode
• Electrically programmable to compensate for
external component tolerances
• Achieves 0.01pA input bias current and 35µV
input offset voltage with micropower
• Low voltage operation
APPLICATIONS
• Sensor interface circuits
• Transducer biasing circuits
• Capacitive and charge integration circuits
• Biochemical probe interface
• Signal conditioning
• Portable instruments
• High source impedance electrode
amplifiers
• Precision Sample and Hold amplifiers
• Precision current to voltage converter
• Error correction circuits
• Sensor compensation circuits
• Precision gain amplifiers
• Periodic In-system calibration
• System output level shifter
PIN CONFIGURATION
ORDERING INFORMATION
Operating Temperature Range
-55°C to +125°C0°C to +70°C0°C to +70°C
14-Pin 14-Pin 14-Pin
CERDIP Small Outline Plastic Dip
Package Package (SOIC) Package
ALD2721E DB ALD2721E SB ALD2721E PB
ALD2721 DB ALD2721 SB ALD2721 PB
* Contact factory for industrial temperature range
BENEFITS
• Eliminates manual and elaborate
system trimming procedures
• Remote controlled automated trimming
• In-System Programming capability
• No external components
• No internal clocking noise source
• Simple and cost effective
• Small package size
• Extremely small total functional
volume size
• Low system implementation cost
• Micropower
1
2
3
4
5
6
7
11
12
13
14
8
9
10
TOP VIEW
DB, PB, SB PACKAGE
VE
2A
VE
1A
V
-
N/C
VE
2B
VE
1B
OUT
B
OUT
A
+IN
A
-IN
A
+IN
B
-IN
B
N/C V
+
© 1998 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, California 94089 -1706 Tel: (408) 747-1155 Fax: (408) 747-1286 http://www.aldinc.com