Buck-Boost Converter with Smooth Transition Circuits and Methods

摘要

A buck-boost converter with smooth transitions is disclosed. A buck-boost converter controller is disclosed including a first high side driver switch gate control signal output for controlling a first high side driver device; a first low side driver switch gate control signal output for controlling a first low side driver device; a second high side driver switch gate control signal output for controlling a second high side driver device; a second low side driver switch gate control signal output for controlling a second low side driver device; a state machine having four states comprising a buck state, a boost state, a transition buck state, and a transition boost state; a hysteresis timer indicating a pulse width greater than a predetermined threshold coupled to the state machine; and a minimum timer indicating a pulse width less than a predetermined threshold coupled to the state machine. Methods are also disclosed.

主权项

1. A buck-boost converter for producing a DC output voltage from a DC input voltage, comprising:
a first high side driver switch coupled between a node for receiving an input voltage and a first node for coupling to an inductor; a first low side driver switch coupled between the first node and a ground voltage; a second high side driver switch coupled between a node for outputting an output voltage and a second node for coupling to the inductor; a second low side driver switch coupled between the second node and a ground voltage; a control circuit for controlling the first high side switch, the second high side switch, the first low side switch, and the second low side switch and configured to operate as a buck-boost converter, and further comprising:
a state machine having four states comprising a buck state, a boost state, a transition buck state, and a transition boost state;a hysteresis timer having an output indicating a pulse width time greater than a threshold time has elapsed coupled to the state machine; anda minimum timer having an output indicating a pulse width time less than a minimum threshold time has elapsed coupled to the state machine.