| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a data output buffer which is highly effective to restrict the consumption of a boosting voltage, more efficient to increase a voltage and fit for high speeds. SOLUTION: A precharging means 112 is provided to temperature perform precharging before a boosting voltage Vpp is supplied to a gate of a pull-up transistor 118. Since it is enough to increase a voltage from Vcc-Vth, the consuming amount of the Vpp is reduced and a boosting effect is enhanced. The Vpp is generated from a boosting voltage generator 70 operating in accordance with a clock frequency divider 80. When the frequency of an internal clock signal CLK is divided half by the frequency divider 80, the boosting voltage generator 70 is enough to operate once while a node DOK is driven two times. Accordingly, a precharging time and a boosting time to obtain the proper Vpp are secured. Even when a supply voltage is low, a stable output operation is ensured.</p> |
