Analog Devices LTC3877 | Demoboard DC2229A-A

Description

Demonstration circuits 2229A-A and 2229A-B feature theLTC®3877 in two high output current, high efficiency, VIDprogrammed step-down converters with sub-mΩ DCRsensing. For both converters, the input voltage range is6V to 14V and the switching frequency is 400kHz.The DC2229A-A provides two outputs. VOUT1 is VIDprogrammable from 0.6V to 1.23V and VOUT2 is set for1.5V. Both rails have a maximum load current of 30A. TheDC2229A-B assembly is a four phase converter providinga VID programmable output of 0.6V to 1.23V with a maximumload current of 120A. Phases 1 and 2 are controlledby the LTC3877 and phases 3 and 4 are controlled by theLTC3874 slave controller.The demo board uses 0.25μH inductors with a DCR value of0.325mΩ. The LTC3877 and LTC3874 employ a proprietarysub-mΩ DCR sensing architecture which enhances thesignal to provide accurate control of the inductor current.The low DCR inductors, along with the use of low Qg/lowRDS(ON) discrete FETs and strong gate drivers provideshigh efficiency for high output current supplies. The fullload efficiency is 90.3%, as seen on the 1.5V rail of theLTC3877 dual output converter (DC2229A-A assembly)with an input voltage of 12V.

Features

Remote sensingn PLLIN and CLKOUT pinsn PGOOD, RUN and TK/SS pinsn Optional resistors to tie two or more phases togethern Optional footprints for BSG0811 dual channel MOSFETsn Optional NTC network on the ITEMP pin of the LTC3877for less current limit variation over temperaturen Dynamic load circuit

More information

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