LT1997-2 Datasheet

• Precision Attenuation: Gain = 0.1, 0.2, 0.25
• ±255V Common Mode Voltage Range
• 105dB Minimum CMRR (Gain = 0.1)
• 0.006% (60ppm) Maximum Gain Error
• 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
• 80μV Maximum Op Amp Offset Voltage
• 1MHz –3dB Bandwidth (Gain = 0.1)
• Low Power Shutdown: 20μA
• Space-Saving MSOP and DFN Packages

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

The LT1997-2 is an attenuating (funnel) difference amplifier that can be used to translate large differential signals to the low voltage range compatible with ADCs. It combines a precision operational amplifier with highly-matched resistors to form a one-chip solution to attenuate and level shift voltages accurately using no external components. It comes with three standard pin-selectable gain options (0.1, 0.2 and 0.25), which can be further combined to form gains from 0.0455 to 0.55 (attenuations of 1.82 to 22) with accuracy of 0.006% (60ppm). The LT1997-2 also works across a very wide input common-mode voltage range (±255V), enabling robust operation in demanding industrial environments. Its excellent resistor matching results in a common mode rejection ratio of greater than 105dB.

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 LT1997-2 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.