LT1990 ±250V Input Range G = 1, 10, Micropower, Difference Amplifier UFEATURESDESCRIPTIO ■ Pin Selectable Gain of 1 or 10 The LT®1990 is a micropower precision difference ampli- ■ High Common Mode Voltage Range: fier with a very high common mode input voltage range. It 85V Window (VS = 5V, 0V) has pin selectable gains of 1 or 10. The LT1990 operates ± 250V (VS = ± 15V) over a ±250V common mode voltage range on a ±15V ■ Common Mode Rejection Ratio: 70dB Min supply. The inputs are fault protected from common ■ Input Protection to ±350V mode voltage transients up to ±350V and differential ■ Gain Error: 0.28% Max voltages up to ±500V. The LT1990 is ideally suited for both ■ PSRR: 82dB Min high side and low side current or voltage monitoring. ■ High Input Impedance: 2MΩ Differential, 500kΩ Common Mode On a single 5V supply, the LT1990 has an adjustable 85V ■ Micropower: 120µA Max Supply Current input range, 70dB min CMRR and draws less than 120µA ■ Wide Supply Range: 2.7V to 36V supply current. The rail-to-rail output maximizes the dy- ■ –3dB Bandwidth: 100kHz namic range, especially important for single supplies as ■ Rail-to-Rail Output low as 2.7V. ■ 8-Pin SO Package The LT1990 is specified for single 3V, 5V and ±15V U supplies over both commercial and industrial temperature APPLICATIO S ranges. The LT1990 is available in the 8-pin SO package. ■ Battery Cell Voltage Monitoring , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ■ High Voltage Current Sensing ■ Signal Acquisition in Noisy Environments ■ Input Protection ■ Fault Protected Front Ends ■ Level Sensing ■ Isolation UTYPICAL APPLICATIOFull-Bridge Load Current Monitor +VSOURCE 5V LT1990 900k 10k 8 7 1M 100k 2 – RS 6 VOUT – + 1M 3 + IL VREF = 1.5V 4 10k IN OUT 5 54.9k 1nF LT6650 40k 900k GND FB 40k 100k 20k –12V ≤ VCM ≤ 73V VOUT = VREF ± (10 • IL • RS) 1 1990 TA01 1µF 1990fb 1