Features and Benefits
- 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
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.
- 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
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Demonstration Circuit 2551A is a Configurable Precision Amplifier featuring the LT1997.
The DC2551A-B supports the LT1997-2 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.
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.