8

FN6454.1

November 2, 2007

DC Path Block Application

Note that there is a DC path in the boost converter from the

input to the output through the inductor and diode, hence the

input voltage will be seen at output with a forward voltage

drop of diode before the part is enabled. If this voltage is not

desired, the following circuit can be inserted between input

and inductor to disconnect the DC path when the part is

disabled.

FIGURE 13. CASCADED MOSFET TOPOLOGY FOR HIGH

OUTPUT VOLTAGE APPLICATIONS

INTERSIL

ISL97519

LX

FB

FIGURE 14. CIRCUIT TO DISCONNECT THE DC PATH OF

BOOST CONVERTER

INPUT

EN

TO INDUCTOR

ISL97519