Renesas Design (UK) Limited

John William Kesterson

Mark Mercer

James Crawford Steele

A step-down converter is presented. The step down converter includes a power stage having at least one phase, each phase comprising an inductor, a driver, and a clock source. The driver drives the power stage in a synchronous mode or in an asynchronous mode of operation with a minimum off time. When the output voltage approaches the input voltage of the converter, a duty cycle of the converter increases up to a value limited by the minimum off time. The clock source generates a first clock signal having a predefined pulse width. The driver generates a first stretchable clock signal having an adjustable pulse width and an adjustable period. Upon transition from the synchronous mode to the asynchronous mode the driver is configured to increase the adjustable pulse width and the period of the first stretchable clock signal.

Step down power converter with pre-dropout control

A driver for driving a switched-mode power supply is presented. The driver receives a set of input signals. Each input signal is configured for changing a state of an associated power switch from a first state to a second state. The driver generates an output signal to change the state of the associated power switch from the first state to the second state. When the first state is an on state and the second state is an off state, the driver asserts the output signal to change the state of the associated power switch to perform an on-off transition. When the first state is the off state and the second state is the on state, the driver delays the assertion of the output signal to perform an off-on transition by a predetermined delay time, so that the off-on transition is delayed until all intended on-off transitions have occurred.

Growing community of inventors

Central Point, OR, United States of America

John William Kesterson