| 摘要 |
<p>A high-voltage generator circuit produces a high voltage that is employed in the operation of an electrically-erasable, programmable read only memory. The circuit is described for MOS implementation as an on chip construction. A charge pump composed of a plurality of stages is driven by a plural-phase-clock-signal operated from a four-phase clock-signal generator which has a frequency determined by an input current. A comparator having an output current that is related to a differential input displays a truncated response; the output current is zero for zero differential input and a maximum output current when the noninverting input potential substantially exceeds the inverting input potential. The noninverting input is coupled to a reference potential and the inverting input is coupled to receive a controlled fraction of the high voltage produced by the charge pump. At start-up, the high voltage is zero and the comparator applies a maximum current to the clock generator which thereby operates at maximum frequency and minimizes startup time. After start-up, the clock frequency will be proportional to the current drawn from the high-voltage generator circuit.</p> |
