Module turns PWM into 25A PSU
Murata has got together with German chip firm ZMDI to produce the Power Block, a small (13x17x11mm) module that includes all the components necessary to make a non-isolated 25A step down dc-dc converter, except for the source of PWM waveform.
OKLP-X/25-W12-C, the first in a series of products, is optimised for use with ZMDI’s ZSPM10x5 digital controllers, but is also suited to controllers from International Rectifier, Linear Tech, Powervation, and TI, said Murata.
Up to 49.5W is available, and efficiency is 93.5% when 3.3V 15A is supplied from 12V.
Output range is 0.8-3.6V, from 7-13Vin, and up to 25A at 1.0V is supported.
On the PCB is a synchronous buck gate driver chip co-packed two power mosfets and a Schottky diode (see circuit). The output LC filter is 375nH and 20μf.
The driver chip needs a separate regulated 5V (4.5-7V, 40mAmax@500kHz) auxiliary supply rail, which has to be established before the PWM starts, said Murata. Driver under-voltage lock-out threshold is 3-4.1Vhysteric.
Intended for 400-600kHz operation, the PWM high threshold is 3.3V compatible (2.5V-(auxiliary+0.3V)).
ZMDI’s PC-based Pink Power Designer provides a user-friendly interface to the ZSPM10x5 for monitoring and configuration of the chip’s voltage control and protection features. A Power Management Bus (PMBus™) interface is supported.