Simplify A/D Converter Interface with Software (TC7135)
Gary Grandbois and Wes Freeman
Integrating analog-to-digital converters (ADCs) featuring binary-coded decimal (BCD) outputs for display interface offer a number of excellent features, as well as high resolution, at a very low cost. These advantages include auto-zeroing, sign-magnitude coding, noise averaging, and high impedance inputs and are also attractive for microprocessor-based systems. Unfortunately, many display-oriented ADCs are difficult to interface due to the multiplexed BCD format of the outputs. An exception is the 4-1/2 digit TC7135 ADC, which provides a "strobe" output.
AN17, A/D Converter Interface, TC7135