Sandisk Technologies Inc.

Potnuru Venkata Pradeep Kumar

Sridhar Yadala

Gooty Sukumar Reddy

A charge pump is connected to receive a supply voltage and a clock signal and generate an output voltage. The charge pump is connected to the supply voltage through a transistor whose gate voltage is set by a regulation voltage determined by feedback from the output voltage. The current supplied to the charge pump through this transistor is mirrored in a section that generates the clock signal, where the mirrored current is used by a current controller oscillator. This allows the pump's clock frequency to linearly track the load current, improving the pump's efficiency.

Dynamic clock period modulation scheme for variable charge pump load currents

A charge pump design suitable for generating high voltages employs multiple low voltage capacitors and low voltage transfer switches, with a limited number of high voltage devices. This is designed such that during a first clock phase, capacitors are each connected between an input voltage and ground and, during a second clock phase all the capacitors are connected in series to generate the required voltage. Both the switches (PMOS) and as well the capacitors are realized as low voltage devices. The ability to use low voltage devices can significantly reduce the area and also a reduction in current consumption relative to the usual high voltage charge pumps which uses high voltage devices.

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Visakhapatnam, India

Potnuru Venkata Pradeep Kumar