Abstract: A negative voltage generator for an integrated circuit includes a charge pump responsive to the current loading on its output terminal. The charge pump is connected to a comparator which compares the output node of the charge pump with a reference potential. The comparator provides an analog output signal to a variable frequency oscillator, which in turn controls the charge pump. Variations in current loading caused the comparator to make appropriate changes in the oscillation frequency.

Abstract: A novel structure and method are taught for fully discharging a capacitor and thereby reducing the capacitance needed to achieve a desired RC time constant. The invention overcomes the previously encountered problem of using a large and area-inefficient capacitor. The invention allows for conservation of integrated circuit space and is cost effective.

Abstract: It is an object of the present invention to provide a variable frequency oscillator capable of operating at low power supply voltage and oscillating at high frequency as well as a phase locked loop and a clock synchronizer using thereof and having a wide oscillation frequency range.

Abstract: The variable frequency oscillator is capable of operation at a low power supply voltage and oscillating at a high frequency. A phase locked loop and a clock synchronizer use the variable frequency oscillator and have a wide oscillation frequency range. The variable frequency oscillator has plural delay cells which are cascaded and the output of the final stage delay cell is fed back to the input of the first stage delay cell. Each of the delay cells includes a differential amplifier and a positive feedback circuit, connected with input and output terminals intersecting with each other. The feedback circuit has complementary amplifiers each having an input terminal formed by connecting together gates of a pMOS and an nMOS transistor and an output terminal formed by connecting together the drains thereof.