CIRCUIT FOR CONTROLLING SUBSTRATE BIAS VOLTAGE

摘要

PURPOSE: A circuit for controlling a substrate bias voltage is provided to achieve a stability and to reduce a power consumption by compensating a voltage according to a voltage differential between a reference voltage of a substrate bias and a sensed threshold voltage. CONSTITUTION: A circuit for controlling a substrate bias voltage comprises a charge pump(10), a threshold voltage sensing part(20), an error amplifying part(30), a boosting part(50) and a voltage adjusting oscillating part(60). The charge pump(10) pumps charges in order to supply a stable substrate bias voltage, and the threshold voltage sensing part senses a threshold voltage of a turned-on transistor in response to a substrate bias voltage applied from the charge pump. The error amplifying part(30) compares a voltage sensed from the sensing part and a reference voltage of a substrate bias to amplify a differential between the voltages. The boosting part(50) boosts an output of the error amplifying part into a predetermined level. The oscillating part(60) oscillates a signal of a predetermined frequency in response to a signal applied at the boosting part, and supplies the oscillated signal to the charge pump.