LT1997-1 Datasheet

• Precision Gain: Up to 80V/V
• Input Common Mode Voltage Range: V^– to V^– + 76V
• 109dB Minimum CMRR (Gain = 10)
• 0.012% (120ppm) Maximum Gain Error (Gain = 10)
• 1ppm/°C Maximum Gain Error Drift
• 2ppm Maximum Gain Nonlinearity
• Wide Supply Voltage Range: 3.3V to 50V
• Rail-to-Rail Output
• 350µA Supply Current
• 65µV Maximum Op Amp Offset Voltage
• 650kHz –3dB Bandwidth (Gain = 10)
• Low Power Shutdown: 20µA
• Space-Saving MSOP and DFN Packages

• High Side or Low Side Current Sensing
• Bidirectional Wide Common Mode Range Current Sensing
• High Voltage to Low Voltage Level Translation
• Industrial Data-Acquisition Front-Ends
• Replacement for Isolation Circuits
• Differential to Single-Ended Conversion

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.