Features and Benefits
- 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
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.Applications
- 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
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Demonstration Circuit 2551A is a Configurable Precision Amplifier featuring the LT1997.
The DC2551A-C supports the LT1997-1 version.
This demo board provides a rapid evaluation tool with jumpers providing the typical interconnection options that facilitate setting the pin-strapped internal gain configuration. The LT1997 is unusual in that it may be powered from a low voltage (down to 3.3V) while it accepts sign particularly high supply voltages, up to 50V. Connection points are provided to wire the amplifier in other configurations besides those possible with the jumpers alone.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
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Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.