Low-power precision differential amplifier drives 20-bit ADCs

A new low-power high-precision fully-differential amplifier, optimized for driving high performance 16-, 18- and 20-bit SAR and ?S ADCs, the LTC6363 has been unveiled by Linear Technology. Featuring 100µV maximum input offset voltage and 2.9nV/vHz input-referred voltage noise, the device consumes just 19mW on a 10V supply. It can convert single-ended signals to differential outputs or be used in a fully differential manner, settling an 8VP-P differential output step to 18-bit resolution in just 780ns. Four external resistors set the LTC6363 gain. The LT5400 family of highly matched quad resistors can be used to achieve excellent linearity. The LTC6363 is stable whether configured for unity gain, higher gain, or attenuation. The LTC6363 operates on a 2.8V to 11V supply. Its outputs swing rail-to-rail and a VOCM pin sets the output common mode voltage for optimal matching to the input range of precision 20-bit SAR ADCs such as the LTC2378-20. The LTC6363 is specified over the -40C to 85C and -40C to 125C temperature ranges, and is available in MSOP-8 and 2mm x 3mm DFN packages.