Programmable current-sensing circuit providing discrete step temperature compensation for DC-DC converter

• Main Authors: SFERRAZZA PAUL K, ISHAM ROBERT HAYNES
• Format: Patent
• Language: English
• Published: 12.06.2003
• Edition: 7
• 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; CONTROL OR REGULATION THEREOF; CONTROLLING; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; PHYSICS; REGULATING; SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES

A programmably switched, multi-output stage current mirror-based, current-sensing and correction circuit controls the operation of a buck mode DC-DC converter. This correction circuit generates a correction current having a prescribed step-wise temperature-compensating relationship to sensed current. The sensed current is derived from a variable impedance controlled by a sense amplifier coupled via a current feedback resistor to the common output node between a high side power switching device and a low side power switching device of the converter. To program the correction circuit a decoder maps temperature information associated with the low side power switching device and additional programming information into a current mirror control code.