Driver circuit for switching converters, corresponding converter and method

A method, comprising:

• receiving an input signal at an input node for conversion in a converter having an output node;
• providing a pulse-width modulated drive signal having an active time to a switching power circuit stage in the converter;
• providing first and second active time generation paths;
• in a first operational mode, selecting a pulse-width modulated drive signal having a first active time value generated in the first active time generation path;
• and
• in a second operational mode, selecting a pulse-width modulated drive signal having a second active time value generated in the second active time generation path,
• wherein the first active time generation path comprises a first active time generator circuit to provide said first active time value, wherein the second active time generation path comprises a second active time generator circuit to provide a digitally-generated second active time value with said second active time value that is adaptively variable to match said first active time value when the method transitions between the first operational mode and the second operational mode, wherein the first active time generation path is enabled in the first operational mode only, and the second active time generator path is enabled in both of the first and second operational modes, wherein an output of the first active time generator circuit is coupled to an input of the second active time generator circuit and directly coupled to an input of a selector circuit, and wherein an output of the selector circuit is directly coupled to the switching power circuit stage in the converter.

A method, comprising:

• in a first operational mode, selecting a pulse-width modulated drive signal having a first active time value generated in a first active time generation path, wherein the first active time generation path comprises a first active time generator circuit to provide said first active time value;
• in a second operational mode, selecting a pulse-width modulated drive signal having a second active time value generated in a second active time generation path, wherein the second active time generation path comprises a second active time generator circuit to provide a digitally-generated second active time value with said second active time value being adaptively variable to match said first active time value when the method transitions between the first operational mode and the second operational mode;
• enabling the first active time generation path in the first operational mode only, and enabling the second active time generator path in both of the first and second operational modes;
• and
• coupling an output of the first active time generator circuit to an input of the second active time generator circuit;
• and
• using a selector circuit for selecting the first and second operational modes, wherein an output of the first active time generator circuit is directly coupled to a first input of the selector circuit, and an output of the second active time generator circuit is directly coupled to a second input of the selector circuit.