Switch controller circuit and method for controlling switching

A method for controlling switching in a topology having a first switch, a second switch, and a switching node coupled therebetween, wherein the method comprises:

• controlling the first and second switches to alternately open and close using a driver arrangement, wherein a deadtime period is applied between the opening of one switch and the closing of the other switch;
• receiving feedback based on a sensed voltage by a voltage sensor connected to the switching node as it transitions between high and low voltage states during the deadtime period;
• and
• setting a length of the deadtime period based on a measured first time period and a multiplier coefficient, wherein the first time period is measured from a time of opening of one of the switches to a time when the sensed voltage transitions through a threshold set between the high and low voltage states;
• wherein the first time period has an algorithmic relationship with a second time period, the second time period being a time between the sensed voltage transitioning through the threshold and the time of closing of the other switch;
• and
• wherein the multiplier coefficient is selected such that the deadtime period is equal to sum of the first time period and the second time period.

A voltage sensor for providing feedback based on a sensed node voltage which varies between high and low voltage states, the voltage sensor comprising:

• an AC reactive divider;
• a DC bias circuit in parallel with the reactive divider for supplying a bias voltage corresponding to the high voltage state and comprising first and second resistors in a voltage divider arrangement for dividing the bias voltage to set a threshold;
• and
• an output for a feedback signal,
• wherein the voltage sensor is configured to generate the feedback signal on the output when the node voltage transitions through the threshold.