Rev 2.1 ©2011 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, CA 94089-1706 Tel: (408) 747-1155 Fax: (408) 747-1286

www.aldinc.com

GENERAL DESCRIPTION

The ALD1721E is a monolithic rail-to-rail precision CMOS operational

amplifier with integrated user programmable EPAD (Electrically Program-

mable Analog Device) based offset voltage adjustment. The ALD1721E

operational amplifier is a direct replacement of the ALD1701 operational

amplifier, with the added feature of user-programmable 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 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 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 perfor-

mance.

The ALD1721E 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 0.7V/

µs, and low typical supply current of 120µA.

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

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

KEY FEATURES

•

EPAD (Electrically Programmable Analog Device)

•

•

Computer-assisted trimming

•

Rail-to-rail input/output

•

Compatible with standard EPAD Programmer

•

High precision through in-system circuit precision trimming

•

•

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

voltage simultaneously

•

Compatible with industry standard pinout

PIN CONFIGURATION

1

2

2

3

4

8

7

6

5

VE1

-IN

+IN

VE2

OUT

N/C

V-

V+

TOP VIEW

SAL, PAL, DA PACKAGES

* N/C Pin is internally connected. Do not connect externally.

Operating Temperature Range

0

°C to +70°C0°C to +70°C

-55

°C to +125°C

8-Pin

8-Pin

8-Pin

Small Outline

Plastic Dip

CERDIP

Package (SOIC)

Package

Package

ALD1721ESAL

ALD1721EPAL

ALD1721EDA

* Contact factory for leaded (non-RoHS) or high temperature versions.

TM

®

N

A

B

L

E

D

E

EPAD® MICROPOWER CMOS OPERATIONAL AMPLIFIER

ALD1721E