US 7,743,266 B2 · Method and system for optimizing filter compensation coefficients for a digital power control system

Abstract

A method and system is provided for optimizing the digital filter compensation coefficients of a digitally controlled switched mode power supply within a distributed power system. A power control system comprises at least one point-of-load (POL) regulator having a power conversion circuit adapted to convey power to a load and a digital controller coupled to the power conversion circuit though a feedback loop. The digital controller is adapted to provide a pulse width modulated control signal to the power switch responsive to a feedback measurement of an output of the power conversion circuit. The digital controller further comprises a digital filter having a transfer function defined by plural filter coefficients. The digital controller periodically stores a successive one of a plurality of samples of the feedback measurement. A serial data bus operatively connects the POL regulator to a system controller. The system controller retrieves each successive stored sample from the digital controller via the serial data bus. After retrieving a pre-determined number of the samples, the system controller calculates optimized filter coefficients for the digital filter and communicates the optimized filter coefficients to the digital controller. The digital controller thereafter uses the optimized filter coefficients in the digital filter.

Claims20

Dependent claims

A power control system comprising:

at least one point-of-load (POL) regulator having a power conversion circuit configured to convey power to a load and a digital controller coupled to the power conversion circuit through a feedback loop, the digital controller being configured to provide a pulse width modulated control signal to said power conversion circuit responsive to a feedback measurement from an output of the power conversion circuit, said digital controller further comprising a digital filter having a transfer function defined by plural filter coefficients, the digital controller periodically storing a successive one of a plurality of samples of said feedback measurement;
a serial data bus operatively connected to said at least one POL regulator;
and
a system controller connected to said serial data bus and configured to communicate with said at least one POL regulator via said serial data bus, said system controller retrieving each said successive stored sample from said digital controller via said serial data bus;
wherein, after retrieving a pre-determined number of said samples, said system controller uses at least a portion of said pre-determined number of said samples to calculate optimized filter coefficients for said digital filter and communicates said optimized filter coefficients to said digital controller via said serial data bus, said digital controller thereafter using said optimized filter coefficients in said digital filter.

2 more elements

A method of controlling at least one point-of-load (POL) regulator coupled to a system controller via a common data bus, the at least one POL regulator having a power conversion circuit configured to convey power to a load and a digital controller coupled to the power conversion circuit in a feedback loop, the digital controller being configured to provide a pulse width modulated control signal to said power conversion circuit responsive to a voltage error measurement, said digital controller further comprising a digital filter having a transfer function defined by plural filter coefficients, the method comprising:

injecting a symmetric noise signal into the pulse width modulated control signal for a predetermined period of time;
storing a sample of the voltage error measurement after allowing sufficient time for the noise signal to settle;
transmitting said sample via the common data bus to the system controller;
repeating the injecting, storing, and transmitting steps a predetermined number of times corresponding to a characteristic of the noise signal;
calculating a transfer function for the feedback loop based on plural ones of said samples;
calculating optimal filter coefficients based on the calculated feedback loop transfer function;
transmitting said optimal filter coefficients to said at least one POL regulator via the common data bus;
and
programming said digital filter using said optimal filter coefficients.

6 more elements

Dependencies are inferred from the claim text.

Method and system for optimizing filter compensation coefficients for a digital power control system

Life of this patent

Method and system for optimizing filter compensation coefficients for a digital power control system

Life of this patent

Abstract

Claims20