Programmable soft start of buck-boost converter

A method comprising:

• retrieving, by control logic of a USB controller, from a register, values for a pulse width and a frequency associated with soft start of a buck-boost converter;
• causing, by the control logic during a soft start in buck mode, a first high-side switch of the buck-boost converter to turn on using pulses having the pulse width and at the frequency;
• causing, by the control logic, a second high-side switch to operate in diode mode;
• causing, by the control logic, a first low-side switch to operate in diode mode;
• detecting, by the control logic, an output voltage at an output terminal of the buck-boost converter that exceeds a threshold value;
• and
• transferring control, by the control logic, to an error amplifier control loop coupled to the control logic in response to the detecting.

A Universal Serial Bus (USB) device comprising:

• a buck-boost converter comprising:
• an input terminal and an output terminal;
• a first high-side switch coupled between the input terminal and a first side of an inductor;
• and
• a second high-side switch coupled between a second side of the inductor and the output terminal;
• a USB Type-C connector comprising a VBUS line;
• and
• an integrated circuit (IC) controller comprising:
• a VBUS terminal coupled to the VBUS line of the USB Type-C connector and to the output terminal of the buck-boost converter;
• a register that is programmable to store a pulse width and a frequency;
• and
• control logic operatively coupled to the register and the buck-boost converter, wherein, to perform a soft start in one of buck mode or boost mode, the control logic is to:
• cause the second high-side switch to operate in diode mode;
• retrieve values of the pulse width and the frequency from the register;
• cause the first high-side switch to turn on using pulses having the pulse width and at the frequency;
• detect an output voltage at the output terminal of the buck-boost converter that exceeds a threshold value;
• and
• in response to the detection, transfer control of the buck-boost converter to an error amplifier control loop coupled to the control logic.