Patent ID: 6459327
Filing Date: 2002-10-01
Classification: H02M,H03K

Abstract:
A feedback controlled substrate bias generator comprising:a substrate bias level sensing circuit coupled to a semiconductor substrate for sensing a bias voltage of the semiconductor substrate and outputting a control signal in response to the sensed bias voltage; a charge pump circuit coupled to the semiconductor substrate and said substrate bias level sensing circuit for receiving the control signal and supplying the bias voltage to the semiconductor substrate in response to the received control signal; and an oscillator coupled to said charge pump circuit for generating a clock pulse, the oscillator including a loop circuit having a plurality of serially and circularly coupled inverters each of which has a source terminal for receiving a voltage from a voltage source, an input terminal for receiving an input signal and an output terminal for outputting an output signal; and a plurality of switches each of which has a first terminal coupled to the source terminal of a corresponding inverter of the loop circuit and a second terminal coupled to the voltage source, each of the switches electrically isolating the first terminal from the second terminal thereof to prevent current flow between said first and second terminals when the output signal of an inverter other than the corresponding inverter changes from one level to another.