The TLC1549C, TLC1549I, and TLC1549Mare 10-bit, switched-capacitor, successive approximation analog-to-digital converters. These devices have two digital inputs and a 3-state output [chip select (CS), input-output clock(I/O CLOCK), and data output (DATA OUT)] that provide a three-wire interface to the serial port ofa host processor. The sample-and-hold function is automatic. The converter incorporated in these devices features differential high-impedance reference inputs that facilitate ratiometric conversion, scaling, and isolation of analog circuitry from logic and supply noise. A switched-capacitor design allows low error conversion over the full operating free-air temperature range. The TLC1549C is characterized for operation from 0oC to 70oC. The TLC1549I is characterized for operation from -40oC to 85oC. The TLC1549M is characterized for operation over the full military temperature range of -55oC to 125oC.