More than just a multiplexer in front of an ADC, the AD7689 family offers pin for pin upgrades from 14-bits to 16-bits and a migration path from low voltage, 250kSPS operation to 500kSPS at 5V. The sequencer allows the user to write to the configuration register via the SDI pin the sequence of channels to be addressed (no ‘bit banging’). The configuration register also controls the input channel configuration (unipolar/bipolar, SE/DIFF), manual channel selection, the bandwidth of the LPF, and the voltage reference.

