Multiplexed, programmable-gain, track-and-hold amplifier has instrumentation inputs

ADCs need adequate signal-acquisition analog interfaces to perform at their best. The classic general-purpose ADC front end includes multiple channels of differential input, digitally programmable gain, and track-and-hold capability. This Design Idea presents a new, complete, high-performance, low-parts-count ADC front end that implements the standard ensemble of functions. However, it also incorporates the concepts of the flying-capacitor differential input and the divergent-exponential negative-time constant that an earlier Design Idea describes. This Design Idea adds to that circuit multiplexed inputs and a versatile track-and-hold function.