| 摘要 |
PURPOSE: A voltage supply control circuit is provided to improve a low voltage operation characteristics by supplying a boosted voltage in case that a power supply voltage supplied to an EPROM cell is dropped below a fixed voltage. CONSTITUTION: A voltage booster(220) boosts a voltage(VCC), and a voltage level detection block(210) enables the voltage booster when the voltage(VCC) is below a specific voltage. A voltage level detection part(230) detects a level of the voltage(VCC), and a voltage supply part(290) supplies a voltage(VPP) or a boosted voltage to an EPROM cell. An inverter(270) inverts a write signal(Wten), and a voltage switching part(280) controls the voltage supply part to supply the voltage(VPP or VCC or 2VCC) to a gate of the EPROM cell with an output signal of the inverter and the write signal as input. A voltage supply part(260) outputs the voltage(VCC or VPP) to the voltage switching part, and an inverter(240) inverts an output signal(venb) of the voltage level detection part. And, a voltage switching part(250) controls the voltage supply part(260) with an output signal of the inverter(240) and the output signal of the voltage level detection part as input.
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