| 摘要 |
<p>PURPOSE:To operate a circuit at a high speed, and to set automatically the best point of the precharge voltage irrelative to the value of an using power source voltage by providing a voltage clamp circuit between a precharge means and a capacity. CONSTITUTION:When a clock pulse phix goes to -VDD level, a precharging FETTp is turned on and a capacity C is charged through a switching FETTc. When a charging voltage V2 exceeds the threshold voltage VLt of an inverter G1, an inverter G1 is reversed and the FETTc is turned off. At this stage, an input Vin reaches -VDD level and FETTc is turned on, then discharging is carried out. However, since the voltage V2 of the capacity C goes approximately to a threshold voltage VLT of the inverter G1, immediately the inverter G1 is reversed. In such a way, the precharge and discharge time can be shortened and the best point of the precharge potential can be set by setting the threshold voltage VLT of the inverter G1.</p> |
