1

LT1490A

Dual Over-The-Top

Micropower Rail-to-Rail

Input and Output Op Amp

s

Low Input Offset Voltage: 500

s

s

Rail-to-Rail Input and Output

s

Micropower: 50

µµµµµA/Amplifier Max

s

MSOP Package

s

Over-The-Top

s

Specified on 3V, 5V and

±15V Supplies

s

High Output Current: 20mA

s

Output Drives 10,000pF with Output Compensation

s

Reverse Battery Protection to 18V

s

No Supply Sequencing Problems

s

High Voltage Gain: 1500V/mV

s

High CMRR: 98dB

s

No Phase Reversal

s

Gain Bandwidth Product: 200kHz

The LT

op amp with improved input offset voltage (500

µV max) and

mended for all new designs. The LT1490A operates on all

single and split supplies with a total voltage of 2V to 44V,

drawing only 40

µA of quiescent current per amplifier. It is

reverse supply protected; it draws virtually no current for

reverse supply up to 18V. The input range of the LT1490A

includes both supplies and the output swings to both sup-

plies. Unlike most micropower op amps, the LT1490A can

drive heavy loads; its rail-to-rail output drives 20mA. The

LT1490A is unity-gain stable and drives all capacitive loads

up to 10,000pF when optional 0.22

µF and 150Ω compensa-

tion is used.

The LT1490A has a unique input stage that operates 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.

s

Battery- or Solar-Powered Systems

Portable Instrumentation

Sensor Conditioning

s

Supply Current Sensing

s

Battery Monitoring

s

Micropower Active Filters

s

4mA to 20mA Transmitters

Battery Monitor

–

+

–

+

RA

2k

Q2

2N3904

S1

S1 = OPEN, GAIN = 1

S1 = CLOSED, GAIN = 10

10k

90.9k

LOGIC

14901A TA01

LOGIC HIGH (5V) = CHARGING

LOGIC LOW (0V) = DISCHARGING

10k

Q1

2N3904

0.2

Ω

CHARGER

VOLTAGE

1/2 LT1490A

1/2 LT1490A

2k

2k

+

2k

LOAD

–

+

–

+

GAIN

=

AMPS

1/2 LT1490A

1/2 LT1490A

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

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

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO