Substrate bias voltage generating circuit for use in a semiconductor device

摘要

A circuit is provided for biasing a semiconductor substrate. The circuit comprises a driving signal generating circuit and a charge pump circuit. The driving signal generating circuit produces first to fourth charge pump driving signals in response to an oscillation signal. Each of the first and fourth charge pump driving signals has a high voltage level that is higher than a power supply voltage. Accordingly, even though the power supply voltage is lowered, a loss of a pump efficiency is prevented because a PMOS transistor in the charge pump circuit is driven by the charge pump driving signal having the voltage higher than the power supply voltage.