DC1822A

Evaluation Board, Ltc3861euhe DC-DC Converter

The demonstration circuit is a dual output synchronous buck converter featuring LTC3861EUHE device. The LTC3861EUHE is a dual PolyPhase synchronous step down switching regulator controller for high current distributed power systems, digital signal processors and other telecom and industrial DC to DC power supplies. The board provides two outputs of 1.5V/25A and 1.2V/25A from an input voltage of 7V to 14V at a switching frequency of 500KHz. The power stage consists of a 6mm × 6mm DrMOS and a 13mm × 13mm iron powder type inductor. An onboard LT3470 buck regulator provides the 5V bias for the LTC3861 and the DrMOS. The demo board uses a high density, two sided drop in layout. The power components, excluding the bulk output and input capacitors, fit within a 1.5inch × 1.2inch area on the top layer. The control circuit fits in a 1.1inch × 1.0inch area on the bottom layer.

.

Efficiency of 91.6% at VOUT1 = 1.5V and 90.7% at VOUT2 = 1.2V

.

Remote sensing for each output

.

CLKIN and CLKOUT pins

.

Optional resistors to tie the two outputs together

.

Connector and header to tie two or more boards together for up to 12 phase operation

.

Optional footprint for an LTC4449 gate driver and discrete MOSFETs

.

Optional footprint for a dual phase Delta power block

.

Operates with power blocks, DrMOS or external gate drivers and MOSFETs

.

Safely powers a prebiased load

.

Power good output voltage monitor