| 摘要 |
PURPOSE:To ensure the sample holding of a large input signal, by providing the 1st and 2nd transitors(TRs) to which the input signal to receive the sample holding is inputted, a differential amplifier, a capacitor, the 3rd and 4th TRs forming a charging/discharging circuit of the capacitor, and an output part respectively. CONSTITUTION:An input signal Vi given from an input terminal 1 turns on TRs 19 and 20 via TRs 15 and 16. When a smapling pulse VP is set at ''H'', a TR7 is turned on to actuate an emitter follower consisting of TRs 16 and 7. Then the signal Vi is supplied to a holding capactior 12. In this case, if the potential Vo of the output signal obtained immediately before sampling is higher than the signal Vi, the electric charge of a holding capacitor 12 is discharged. While the electric charge of the capacitor 12 is charged when the Vo is lower than the Vi. This ensures the sample holding with good follow-up performance and high accuracy to an input signal having a big change of amplitude. |
