Journal of Semiconductor Technology and Science (JSTS)
In a high-speed flash style or a pipelining style Analog-to-Digital converter (A/D converter), the DC reference fluctuation caused by external noises becomes serious, as the sampling frequency is increased. To reduce the fluctuations in conventional A/D converters, capacitors have been simply used, but the layout area was large. Instead of capacitors, a low-noise and small-size DC reference circuit based on Transmission Gate (TG) is proposed in this paper. In order to verify the proposed technique, the authors designed and manufactured a 6-bit 2GSPS CMOS A/D converter.