Mixed mode control for switching regulator with fast transient responses

A multiple output switching regulator controller, comprising:

• a) a power stage configured to power a plurality of loads by providing a corresponding plurality of output terminals at a corresponding plurality of different output voltages by converting an input signal;
• and
• b) a first feedback circuit configured to amplify an output regulation difference between each said output terminal and a corresponding regulation reference using time division multiplexing (TDM), said first feedback circuit being configured to generate a plurality of control signals corresponding to said plurality of output terminals, each said control signal being generated during a predetermined time interval using said TDM, and each said control signal being held until a next sensing interval, wherein each said control signal is configured to control said switching regulator to match a corresponding output terminal to said corresponding regulation reference during a steady state operation of said switching regulator,
• c) wherein said first feedback circuit comprises a feedback controller and a time division controller that are coupled to first and second multiplexers, said first multiplexer being coupled to said plurality of output terminals, and said second multiplexer being coupled to a plurality of compensation signals corresponding to said plurality of control signals.

A method of controlling a switching regulator, the method comprising:

• a) amplifying a first regulation difference between an output terminal and a regulation reference using a first feedback circuit;
• b) generating a control signal from said amplified difference for steady state operation of said switching regulator;
• c) sensing a plurality of second regulation differences between said output terminal and a plurality of predetermined thresholds based on said regulation reference using a second feedback circuit;
• and
• d) generating a single adjustment signal for adjusting said control signal under transient conditions to adjust a duty cycle of a power stage of said switching regulator to improve a transient response of said switching regulator, wherein said single adjustment signal is generated from said plurality of second regulation differences, wherein said second feedback circuit comprises a non-linear circuit having a first amplifier for amplifying a difference between said output and a first of said plurality of predetermined thresholds, a second amplifier for amplifying a difference between said output and a second of said plurality of predetermined thresholds, and a first summation circuit for summing outputs from said first and second amplifiers to provide said single adjustment signal.

A method of controlling a multiple output switching regulator, the method comprising:

• a) dividing a sensing period into a plurality of time intervals;
• b) amplifying an output regulation difference between each of a plurality of output terminals and a corresponding regulation reference using a first common feedback circuit, wherein said plurality of output terminals are not connected together and are at a corresponding plurality of different output voltages;
• c) generating a corresponding control signal in a corresponding time interval, wherein said corresponding control signal is held until a next sensing interval of said plurality of time intervals;
• and
• d) using each said control signal to produce a stable output level at said corresponding output terminal to match said corresponding regulation reference during steady state operation, wherein said first feedback circuit comprises a feedback controller and a time division controller that are coupled to first and second multiplexers, said first multiplexer being coupled to said plurality of output terminals, and said second multiplexer being coupled to a plurality of compensation signals corresponding to said plurality of control signals.