Patent ID: 6087816
Filing Date: 2000-07-11
Classification: H02M

Abstract:
A converter for step-up and step-down operation having a converter input, a converter output and a common connection, comprising:an inductor having first and second connections;a first transistor coupled between the converter input and the first inductor connection;a first rectifying device coupled between the first inductor connection and the common connection;a second transistor coupled between the second inductor connection and the common connection;a second rectifying device coupled between the second inductor connection and the converter output;a controller controlling the state of conduction of the first and second transistors responsive to a compensated converter output and a clock signal, the controller having three states of operation, a first state turning the first and second transistors off, a second state turning the first and second transistors on, and a third state turning the first transistor on and second transistor off, the controller switching from the third state to the first state on clock pulses occurring when the compensated converter output indicates an over regulation condition and switching back to the third state when the compensated converter output changes to indicate an under regulation condition, and the controller switching from the third state to the second state on clock pulses occurring when the compensated converter output indicates an under regulation condition and switching back to the third state when the compensated converter output changes to indicate an over regulation condition.