Abstract: A programmable after-package, on-chip reference voltage trim circuit for an integrated circuit having a plurality of programmable trim cells generating a programmed sequence. A converter is provided to convert the bit sequence into a trim current. The trim current is added to an initial value of a reference voltage to be trimmed, as generated by the integrated circuit. Once the correct value of the trim current is determined, isolation circuitry is programmed to isolate the trim circuitry from the remainder of the IC, thereby freeing the logic and package pins associated with the IC for use by users of the IC. The preferred trim circuitry includes fuses which are blown in accordance with a bit value supplied to the trim cell to permanently fix a trim current value, once a best fit value is determined.

Abstract: A DC-DC converter for converting DC power received from a high-voltage DC power supply to a well-regulated output voltage that is significantly lower than the received voltage. The converter includes a regulated voltage-reduction stage which receives high-voltage DC electrical power and supplies DC electrical power at a voltage which is lower than that received. The converter also includes a separately regulated electrically isolated stage, energized by electrical power received from the voltage-reduction stage, that supplies DC electrical power to a load at the significantly lower output voltage. A feedback circuit couples an output signal from the output of the isolation-stage for regulating operation of the voltage-reduction stage and of the isolation stage.

Abstract: An active transient-control circuit included in a power supply responds swiftly to changes occurring in the output-power voltage produced by a power converter to reduce transient changes in the output-power voltage caused by sudden, substantial changes in the electrical current drawn by the load. To respond in this way, when the output-power voltage has a magnitude less than a lower pre-established-voltage threshold, the active transient-control circuit supplies electrical energy directly to the load from the input electrical power thereby augmenting output electrical power supplied to the load by the power converter. Correspondingly, when the output-power voltage has a magnitude that exceeds an upper pre-established-voltage threshold, the active transient-control circuit draws electrical energy directly from the output of the power converter.

Abstract: An active transient-control circuit included in a power supply responds swiftly to changes occurring in the output-power voltage produced by a power converter to reduce transient changes in the output-power voltage caused by sudden, substantial changes in the electrical current drawn by the load. To respond in this way, when the output-power voltage has a magnitude less than a lower pre-established-voltage threshold, the active transient-control circuit supplies electrical energy directly to the load from the input electrical power thereby augmenting output electrical power supplied to the load by the power converter. Correspondingly, when the output-power voltage has a magnitude that exceeds an upper pre-established-voltage threshold, the active transient-control circuit draws electrical energy directly from the output of the power converter.