Rev. 4.0 5/22/2010
International Rectifier
Page 12 of 16
PROPRIETARY INFORMATION - This document and the information contained therein are proprietary and are not to be reproduced, used or disclosed
to others for manufacture or any other purpose except as specifically authorized in writing by
INTERNATIONAL RECTIFIER.
5.2 Short Circuit Protection
IRS27951 uses high-voltage technology to sense the current in the low-side MOSFET. The voltage at the VS
node is sensed when the low-side device is turned ON and the system shuts off when a load short-circuit
condition is sensed (i.e. I
D
*R
DSON
exceeds the fixed internal threshold). In this reference design, IRS27951
latched shutdown when primary current exceed 8.9A peak.
Ch 2
: 12V Rail Output Voltage
Ch 3
: 12V Rail Output Voltage
Ch 4
: Resonant tank current
24V Rail short-circuit
12V Rail short circuit