Front End Integrates Sequencing For POL Converters

Operating from an input range of 36V to 75V, the HBCS25ZH 300W, half-brick dc/dc front end provides sequencing for up to four point-of-load (POL) converters, eliminating the need for an external controller. The sequencing is integrated with the front-end's intermediate bus-voltage monitor, and each of the sequencing signals can be programmed for a delay of 1 ms to 50 ms after the intermediate bus has reached 88% of nominal voltage. Power-down sequencing is activated when the bus reaches 80% of nominal voltage. Other features include efficiencies up to 94%, 1.5 kVdc input-to-output isolation, basic insulation, high capacitive-load capability, wide-output voltage trim, low conducted and radiated EMI, and standard protection features. Price is $63 each in OEM quantities. POWER-ONE INC., Andover, MA. (805) 987-8741.