±250V Input Range G = 1, 10, Micropower, Difference Amplifier

The LT1990 is a micropower precision difference amplifier with a very high common mode input voltage range. It has pin selectable gains of 1 or 10. The LT1990 operates over a ±250V common mode voltage range on a ±15V supply. The inputs are fault protected from common mode voltage transients up to ±350V and differential voltages up to ±500V. The LT1990 is ideally suited for both high side and low side current or voltage monitoring.

On a single 5V supply, the LT1990 has an adjustable 85V input range, 70dB min CMRR and draws less than 120µA supply current. The rail-to-rail output maximizes the dynamic range, especially important for single supplies as low as 2.7V.

The LT1990 is specified for single 3V, 5V and ±15V supplies over both commercial and industrial temperature ranges. The LT1990 is available in the 8-pin SO package.

Applications

* Battery Cell Voltage Monitoring

* High Voltage Current Sensing

* Signal Acquisition in Noisy Environments

* Input Protection

* Fault Protected Front Ends

* Level Sensing

* Isolation

* Pin Selectable Gain of 1 or 10

* High Common Mode Voltage Range:

* 85V Window (VS = 5V, 0V)

* ±250V (VS = ±15V)

* Common Mode Rejection Ratio: 70dB Min

* Input Protection to ±350V

* Gain Error: 0.28% Max

* PSRR: 82dB Min

* High Input Impedance: 2MΩ Differential, 500kΩ Common Mode

* Micropower: 120µA Max Supply Current

* Wide Supply Range: 2.7V to 36V

* –3dB Bandwidth: 100kHz

* Rail-to-Rail Output

* 8-Pin SO Package