LT1997 Series

The LT1997-1 is a difference amplifier that can be used to amplify small differential signals while rejecting large common mode signals making it an ideal choice for current sense applications. It combines a precision operational amplifier with highly-matched resistors to form a one-chip solution to amplify and level shift voltages accurately using no external components. It comes with three standard pin-selectable gain options (10, 20 and 50), which can be further combined to form gains from 0.141 to 80 with accuracy of 0.012% (120ppm). The LT1997-1 also operates with input voltages between V–and V–+ 76V (independent of V+), enabling robust operation in demanding industrial environments. Its excellent resistor matching results in a common mode rejection ratio of greater than 109dB (Gain = 10).The resistors maintain their excellent matching over temperature; the matching temperature coefficient is guaranteed less than 1ppm/°C. The resistors are extremely linear with voltage, resulting in a gain nonlinearity of less than 2ppm.The LT1997-1 is fully specified at 5V and ±15V supplies and from –40°C to 125°C. The device is available in space saving 16-lead MSOP and 4mm × 4mm DFN14 packages.ApplicationsHigh Side or Low Side Current SensingBidirectional Wide Common Mode Range Current SensingHigh Voltage to Low Voltage Level TranslationIndustrial Data-Acquisition Front-EndsReplacement for Isolation CircuitsDifferential to Single-Ended Conversion