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 ALD1721/ALD1721G is a monolithic CMOS micropower high slew

rate operational amplifier intended for a broad range of precision applica-

tions requiring exremely low input signal power. Input signal power is the

product of input offset voltage and input bias current, which represents the

minimum required power draw from the signal source in order to drive the

input of the operational amplifier. Input signal power is also a figure of

merit in source loading and its associated error, and is a measure of the

basic signal resolution possible through the operational amplifier for a

given signal source. For certain types of signal sources, signal loading

directly translates into a significant distortion or "interface noise equiva-

lent" term.

The ALD1721/ALD1721G is designed to set a new standard in low input

signal power requirements. The typical input loading at its input is 0.05 mV

offset voltage and 0.01 pA input bias current at 25C, resulting in 0.0005

fW input signal power draw. This input characteristic virtually eliminates

any loading effects on most types of signal sources, offering unparalled

accuracy and signal integrity and fidelity. Obviously, for capacitive and

high sensitivity, high impedance signal sources, the ALD1721/

ALD1721G is ideally suited. It is readily suited for +5V single supply (or

±1V to ±5V) systems, with low operating power dissipation, a traditional

strength of CMOS technology. It is offered with industry standard pin

configuration of

µA741 and ICL7611 types.

The ALD1721/ALD1721G can operate with rail to rail large signal input

and output voltages with relatively high slew rate. The input voltage can

be equal to or exceed the positive and negative supply voltages while the

output voltage can swing close to these supply voltage rails. This feature

significantly reduces the supply overhead voltage required to operate the

operational amplifier and allows numerous analog serial stages to oper-

ate in a low power supply environment. In addition, the device can

accommodate mixed applications where digital and analog circuits may

operate off the same power supply or battery. Finally, the output stage

can typically drive up to 50pF capacitive and 10K

Ω resistive loads.

These features make the ALD1721/ALD1721G a versatile, micropower

high precision operational amplifier that is user friendly and easy to use

with virtually no source loading and zero input-loading induced source

errors. Additionally, robust design and rigorous screening make this

device especially suitable for operation in temperature-extreme environ-

ments and rugged conditions.

FEATURES & BENEFITS

• Lead Free - RoHS compatible

• Robust high-temperature operation

• Guaranteed extremely low input signal

power of 1.5 fW

• Input offset voltage of 0.05 mV typical

(0.15 mV max.)

• Low input bias currents of 0.01pA typical

(10pA max.)

• Rail to rail input and output voltage ranges

• All parameters specified for +5V single

supply or

±2.5V dual supplies

• Unity gain stable, no compensation needed

• High voltage gain -- typically 100V/mV @

±2.5V(100dB)

• Drive as low as 10K

Ω load

• Output short circuit protected

• Unity gain bandwidth of 0.7MHz

• Slew rate of 0.7V/

µs

• Micro power dissipation

• Suitable for rugged, temperature-extreme

environments

APPLICATIONS

• Voltage amplifier

• Voltage follower/buffer

• Charge integrator

• Photodiode amplifier

• Data acquisition systems

• High performance portable instruments

• Signal conditioning circuits

• Sensor and transducer amplifiers

• Low leakage amplifiers

• Active filters

• Sample/Hold amplifier

• Picoammeter

• Current to voltage converter

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

ALD1721SAL

ALD1721PAL

ALD1721DA

ALD1721GSAL

ALD1721GPAL

ALD1721GDA

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

ORDERING INFORMATION (“L” suffix denotes lead-free (RoHS))

PIN CONFIGURATION

* N/C pins are internally connected. Do not connect externally.

1

2

2

3

4

8

7

6

5

TOP VIEW

N/C

-IN

+IN

N/C

OUT

N/C

V-

V+

TOP VIEW

SAL, PAL, DA PACKAGES

TM

®

N

A

B

L

E

D

E

PRECISION MICROPOWER CMOS OPERATIONAL AMPLIFIER

ALD1721/ALD1721G