Circuit for controlling converters, corresponding converter device and method

A converter device, comprising:

• a half-bridge arrangement comprising high-side electronic switches and low-side electronic switches having an intermediate node therebetween, the converter device comprising an output node configured to provide an output signal from the converter device and drive nodes coupled to high-side electronic switches and low-side electronic switches in the half-bridge arrangement;
• a differential circuit having a first input node configured to receive a reference signal and a second input node configured to receive a feedback signal which is a function of the output signal, said differential circuit being sensitive to the output signal at said output node;
• a comparator having a comparator output node configured to produce a PWM-modulated signal for controlling said half-bridge arrangement as a function of the duty cycle of said PWM-modulated signal, said comparator having a first input node coupled to the intermediate node, and a second input node coupled to an output node of said differential circuit;
• and
• a gain circuit block coupled between said intermediate node in said half-bridge arrangement and said first input node of said comparator, the gain circuit block configured to generate a ramp signal that is applied to said first input node of said comparator, wherein said ramp signal is generated from a signal at said intermediate node in said half-bridge arrangement by applying a variable gain scaling to the signal at said intermediate node in said half-bridge arrangement.

A circuit, comprising:

• a converter circuit configured to generate an output signal at an output node, said converter circuit including a first half-bridge circuit and a second half-bridge circuit that share a common intermediate node, wherein the converter circuit is configurable for operation in a plurality of operating states including a first state where the first half-bridge circuit is active and the second half-bridge circuit is inactive and a second state where the first half-bridge circuit is inactive and the second half-bridge circuit is active;
• a differential circuit configured to generate a first signal in response to a difference between a reference signal and a feedback signal which is a function of the output signal;
• a gain circuit configured to sense a voltage at the common intermediate node, apply a variable gain scaling to the sensed voltage at the common intermediate node to generate a scaled signal, and sum said scaled signal with a ramp signal to generate a second signal;
• a comparator configured to generate a PWM-modulated signal for controlling driving of the first and second half-bridge circuits of said converter circuit in accordance with a selected one of the plurality of operating states, the comparator having a first input configured to receive the first signal and a second input configured to receive the second signal;
• and
• wherein a magnitude of the variable gain scaling is dependent on the selected one of the plurality of operating states.

A circuit, comprising:

• a converter circuit configured to generate an output signal at an output node, said converter circuit including a first half-bridge circuit and a second half-bridge circuit that share a common intermediate node, wherein the converter circuit is configurable for operation in a plurality of operating states including a first state where the first half-bridge circuit is active and the second half-bridge circuit is inactive and a second state where both the first half-bridge circuit and the second half-bridge circuit are active;
• a differential circuit configured to generate a first signal in response to a difference between a reference signal and a feedback signal which is a function of the output signal;
• a gain circuit configured to sense a voltage at the common intermediate node, apply a variable gain scaling to the sensed voltage at the common intermediate node to generate a scaled signal, and sum said scaled signal with a ramp signal to generate a second signal;
• a comparator configured to generate a PWM-modulated signal for controlling driving of the first and second half-bridge circuits of said converter circuit in accordance with a selected one of the plurality of operating states, the comparator having a first input configured to receive the first signal and a second input configured to receive the second signal;
• and
• wherein a magnitude of the variable gain scaling is dependent on the selected one of the plurality of operating states.