Voltage converter controller and voltage converter circuit

A voltage converter controller adapted to a voltage converter circuit, the voltage converter circuit operates a high-side power switch and a low-side power switch to convert an input voltage to an output voltage through an inductor, wherein a channel of the high-side power switch, a channel of the low-side power switch, and the inductor are coupled at a phase terminal, the voltage converter controller comprising:

• a pulse-width-modulation (PWM) signal, indicating the conduction and cut-off of the channel of the high-side power switch and the channel of the low-side power switch;
• a power switch controller, receiving the PWM signal whereby the power switch controller outputs a high-side control signal and a low-side control signal which respectively control the conduction and cut-off of the channel of the high-side power switch and the channel of the low-side power switch, wherein at most one of the channel of the high-side power switch and the channel of the low-side power switch is conducted concurrently, and when the power switch controller starts to control the low-side power switch cut-off, after a first dead-time, the power switch controller starts to control the high-side power switch conducting;
• and
• a dead-time determining circuit, detecting a current of the conducting channel of the low-side power switch to determine a value of the first dead-time,
• wherein when the current of the conducting channel of the low-side power switch is larger than a current threshold, the first dead-time is determined to be a first value;
• wherein when the current of the conducting channel of the low-side power switch is smaller than the current threshold, the first dead-time is determined to be a second value, and wherein the second value is larger than the first value.