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

摘要

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.