Comparison of Binary and Multi-Level Logic Processing for an Optical Encoder

The measurement of rotation is required for many sensor systems. Rotary optical encoders are a rugged option for such measurements and gray code systems help prevent ambiguous values during transitions. A complex interface task is selected to compare binary and multi-level logic implementations in which a five-bit, encoder gray code maps to seven-segment displays. An optimized binary gate implementation is compared to a functional equivalent using a multi-level, memory-based logic approach. CMOS circuit implementations are compared with respect to transistor count, propagation delay, and power usage. The suitability of the multi-level, memory-based approach for low-power, dedicated instrumentation is discussed