1

LT1490A/LT1491A

sn1490, 14901afbs

Dual/Quad Over-The-Top

Micropower Rail-to-Rail

Input and Output Op Amps

µµµµµA/Amplifier Max

■

Over-The-Top

±15V Supplies

■

No Supply Sequencing Problems

× 3mm × 0.8mm DFN Package

low input offset voltage of 500

µVmax.TheLT1490A/LT1491A

operate on all single and split supplies with a total voltage of

2V to 44V, drawing only 40

µA of quiescent current per

amplifier. These amplifiers are reverse supply protected;

they draw virtually no current for reverse supply up to 18V.

The input range of the LT1490A/LT1491A includes both

supplies and the output swings to both supplies. Unlike most

micropower op amps, the LT1490A/LT1491A can drive

heavy loads; their rail-to-rail outputs drive 20mA. The

LT1490A/LT1491A are unity-gain stable and drive all capaci-

tive loads up to 10,000pF when optional 0.22

µF and 150Ω

compensation is used.

The LT1490A/LT1491A have a unique input stage that oper-

ates and remains high impedance when above the positive

supply. The inputs take 44V both differential and common

mode even when operating on a 3V supply. Built-in resistors

protect the inputs for faults below the negative supply up to

15V. There is no phase reversal of the output for inputs 15V

The LT1490A dual op amp is available in the 8-pin MSOP,

PDIP and SO packages. For space limited applications

LT1490A is available in a 3mm

× 3mm × 0.8mm, dual fine

pitch leadless package (DFN). The quad LT1491A is available

in the 14-pin SO, PDIP and 5mm

× 3mm × 0.8mm DFN

packages.

Portable Instrumentation

Sensor Conditioning

■

Micropower Active Filters

Battery Monitor

–

+

–

+

RA

2k

Q2

2N3904

S1

S1 = OPEN, GAIN = 1

S1 = CLOSED, GAIN = 10

10k

90.9k

LOGIC

1490A TA01

LOGIC HIGH (5V) = CHARGING

LOGIC LOW (0V) = DISCHARGING

10k

Q1

2N3904

0.2

Ω

CHARGER

VOLTAGE

1/4 LT1491A

1/4 LT1491A

2k

2k

+

2k

LOAD

–

+

–

+

GAIN

=

AMPS

1/4 LT1491A

1/4 LT1491A

, LTC and LT are registered trademarks of Linear Technology Corporation.

Over-The-Top is a registered trademark of Linear Technology Corporation.

Protected by U.S. Patents including 5825228.

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO