DESIGN IDEAS L High Power 2-Phase Synchronous
Boost Replaces Hot Diodes with
Cool FETs—No Heat Sinks Required
by Narayan Raja, Tuan Nguyen and Theo Phillips Introduction
For low power designs, non-synchronous boost converters offer a simple
solution. However, as power levels increase, the heat dissipated in the boost
diode becomes a significant design
problem. In such cases, a synchro-nous boost converter, with the diode
replaced with a lower forward voltage
drop switch, significantly improves efficiency and relieves many issues with
thermal layout. Although the topology
is more complicated, Linear Technol5V ogy offers controller ICs that simplify
the design of high power synchronous
boost applications. The LT3782A boost
controller, for instance, includes predrive outputs for external synchronous
switch drivers. It also integrates strong PD3S160
Q1
VCC 1ВµF GND LTC4440-5 IN
4.7ВµF
VIN
10V TO 14V + 680ВµF 1ВµF TG
DFLS160 TS SGATE1 10ВµF
s4 BST L1 …