The PC659A is a 8-bit A/D converter for video signal processing, the power consumption of which is lower than the PC659. The high speed and high quality bipolar processing technology has enabled fast conversion rate and high resolution to be achieved. Conversion rate is up to 20 Msps (sampling per second) and linearity error within 0.5 LSB while operating at low power consumption. Wide variety of application can be realized in digital application field such as digital TV system and high speed facsimile. Also, this IC includes sample and hold circuit, clamp circuit and reference voltage generator, which enable simple external circuit to be constructed. The PC659A and the PC659 are different in the number of clock pulses till transformed data is output after analog signal is captured. This should be taken into consideration when using the PC659A instead of the PC659. For details, refer to the timing chart.