A
DVANCED
L
INEAR
D
EVICES,
I
NC.
ALD1721E/ALD1721
EPAD™ MICROPOWER OPERATIONAL AMPLIFIER
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
High precision through in-system circuit precision 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 35
µ
V
input offset voltage simultaneously
Compatible with industry standard pinout
BENEFITS
• Eliminates manual and elaborate
system trimming procedures
• Remote controlled automated trimming
• In-System Programming capability
• No external components
• No internal chopper clocking noise
• No chopper dynamic power dissipation
• Simple and cost effective
• Small package size
• Extremely small total functional
volume size
• Low system implementation cost
• Micropower and Low Voltage
GENERAL DESCRIPTION
The ALD1721E/ALD1721 is a monolithic rail-to-rail precision CMOS
operational amplifier with integrated user programmable EPAD (Electri-
cally Programmable Analog Device) based offset voltage adjustment. The
ALD1721E/ALD1721 operational amplifier is a direct replacement of the
ALD1701 operational amplifier, with the added feature of user-program-
mable offset voltage trimming resulting in significantly enhanced total
system performance and user flexibility. EPAD technology is an exclusive
ALD design which has been refined for analog applications where preci-
sion 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
within the device even after power-down. EPAD offers the circuit designer
a convenient and cost-effective trimming solution for achieving the very
highest amplifier/system performance.
The ALD1721E/ALD1721 operational amplifier features rail-to-rail input
and output voltage ranges, tolerance to over-voltage 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 0.7 V/µs, and low typical supply current
of 120 uA.
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
VE1
1
2
3
4
TOP VIEW
DA, PA, SA PACKAGE
2
8
7
6
5
VE2
V+
OUT
N/C
ORDERING INFORMATION
Operating Temperature Range
-55°C to +125°C
8-Pin
CERDIP
Package
ALD1721E DA
ALD1721 DA
0°C to +70°C
8-Pin
Small Outline
Package (SOIC)
ALD1721E SA
ALD1721 SA
0°C to +70°C
8-Pin
Plastic Dip
Package
ALD1721E PA
ALD1721 PA
-IN
+IN
V-
* Contact factory for industrial temperature range
© 1998 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, California 94089 -1706 Tel: (408) 747-1155 Fax: (408) 747-1286 http://www.aldinc.com
ALD [ ADVANCED LINEAR DEVICES ]
