Linear Technology introduced a unity gain difference amplifier which combines excellent DC precision, a very high-input common mode range and a wide supply voltage range. Applications include high side or low side current sensing, high voltage to low voltage level translation, precision difference amplifier and industrial data-acquisition front-ends.
The chip includes a precision op amp and a highly-matched thin film resistor network. It features excellent CMRR, extremely low gain error and extremely low gain drift.
Comparing the LT6375 to existing difference amplifiers with high common mode voltage range, the selectable resistor divider ratios of the LT6375 offer superior system performance by allowing the user to achieve maximum SNR, precision and speed for a specific input common mode voltage range.
The features of the A-grade version include a CMRR of 97dB (min), initial gain error of 35ppm (max), gain drift of 1ppm/°C (max) and gain nonlinearity of 2ppm (max) with a common mode divide ratio of 25:1.
The op amp in the LT6375 has Over-The-Top protected inputs which allow for robust operation in environments with unpredictable voltage conditions.
The common mode divide ratio is selectable from 7:1 to 25:1, enabling the designer to select the ratio with the best performance for a given common mode input range.
Other useful features include rail-to-rail outputs, low supply current and a shutdown mode. The device is fully specified over the 40°C to 125°C temperature range and available in space-saving DFN and MSOP packages.