| 摘要 |
A back bias voltage generator comprising a power-on signal generator for generating a power-on signal when an external voltage remains at a constant level, a reference voltage generator for generating a reference voltage in response to the power-on signal from the power-on signal generator, an internal voltage generator for generating an internal voltage and an internal/external voltage select signal in response to the reference voltage from the reference voltage generator, the internal voltage being constant in level, a back bias voltage sensor for generating an oscillation enable signal in response to the external voltage or the internal voltage from the internal voltage generator under control of the internal/external voltage select signal from the internal voltage generator, an oscillator for generating an oscillating signal at a desired period and an enable signal in response to the oscillation enable signal from the back bias voltage sensor and outputting the generated enable signal to the internal voltage generator, and a back bias voltage pump for performing a voltage pumping operation in response to the oscillating signal from the oscillator to generate a desired level of back bias voltage and outputting the generated back bias voltage to an external circuit and the back bias voltage sensor. |
