Switching power supply controller with selective feedback sampling and waveform approximation

• Main Author: RICHARDSON KENNETH G
• Format: Patent
• Language: English
• Published: 21.01.2014
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS,e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USERAPPLICATIONS; CONTROL OR REGULATION THEREOF; CONTROLLING; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERATION; PHYSICS; REGULATING; SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

A switching power supply controller which includes at least one switching element, and controls a switching cycle during which the switching elements are switched on and off to regulate the power supply's output voltage. The controller has a feedback signal which represents the output voltage, and a circuit node which conducts a current that is higher during a second portion of the switching cycle than it is during a first portion, such that the feedback signal varies with the current conducted by the node. To overcome feedback signal inaccuracies, a sampling circuit samples a signal which varies with the feedback signal only during the first portion of the switching cycle; the controller then regulates the output voltage in response to the sampled signal. The sampling circuit may be further arranged to produce an output which approximates the portion of the feedback signal waveform which is not sampled.