Abstract: The present disclosure provides a system and method for managing a four-switch BUCKBOOST converter with a combination of a Constant Off-time (COT) control and a Peak Current Mode (PCM) control. With the COT control, the four-switch BUCKBOOST converter can automatically and smoothly transition between a BUCK mode, a BUCKBOOST mode, and a BOOST mode when input voltage varies. In some implementations, the four-switch BUCKBOOST converter only requires a simple, low-power-consumption and robust system control loop compensation with the PCM control for inductor current, and, thus, eliminates the need for oscillator and slope compensation circuit. The PCM control is used to determine turn-off-timing of switches of the four-switch BUCKBOOST converter. The system control loop compensation can provide cycle-by-cycle current limit function to protect the converter and load from over-current damages.

Abstract: A synchronous buck direct current to direct current (DC-DC) converter includes a signal output terminal, an output stage circuit, a first comparator, a latch, a control logic circuit, a driver circuit and an on-time control circuit. The output stage circuit provides an output voltage to the signal output terminal according to an input voltage. The first comparator receives a reference voltage and a feedback signal related to the output voltage and outputs a control signal. The latch receives the control signal and a timing signal and outputs an on-enable signal. The control logic circuit receives the on-enable signal and outputs an on-control signal. The driver circuit controls charge/discharge time of the output stage circuit according to the on-control signal. The on-time control circuit receives the on-control signal and the input voltage and outputs the timing signal related to a duty cycle of the output stage circuit.

Abstract: A synchronous buck direct current to direct current (DC-DC) converter includes a signal output terminal, an output stage circuit, a first comparator, a latch, a control logic circuit, a driver circuit and an on-time control circuit. The output stage circuit provides an output voltage to the signal output terminal according to an input voltage. The first comparator receives a reference voltage and a feedback signal related to the output voltage and outputs a control signal. The latch receives the control signal and a timing signal and outputs an on-enable signal. The control logic circuit receives the on-enable signal and outputs an on-control signal. The driver circuit controls charge/discharge time of the output stage circuit according to the on-control signal. The on-time control circuit receives the on-control signal and the input voltage and outputs the timing signal related to a duty cycle of the output stage circuit.