A high precision and low noise S/H circuit design for video signal sampling

This paper presents an improved sample/hold (S/H) circuit design for analog LCD applications. The circuit possesses the dual characteristics of high sampling precision and low switch noise and is thus suitable for video signal sampling applications. In order to increase accuracy of sampling and to reduce switch noise, the design uses an operational amplifier with current-mode switch, which incorporates an improved buffer amplifier, and introduces a noise elimination technique by using a differential amplifier. The simulation results show that for a typical signal sampling application and its BiCMOS implementation, the design has achieved a minimal signal distortion and significantly reduced noise effect.