March 2006 REVISION 09

SH 28 of 31

Technical Reference Note

AIF - PFC Power Factor

Correction Series

Brown Out Ride Through

Brown Out conditions occurs when there is a transient break in input current. During this period the external output bulk

capacitor holds up the voltage to the load until input current is restored. When the input voltage is restored the PFC module

will continue delivering power to the load

315V for Vadj to 76%

(390V for Vadj to 100%)

290V for Vadj to 76% 

(380V for Vadj to 100%)

280V

LOW

+O/P

-O/P

85 to 265Vac

L1

L2

9

8

1

16

+

Output to

AMPSSô

Modules or 

other load

APA

250V(Min)

INPUT VOLTAGE

OUTPUT VOLTAGE

PFW

BROWN OUT

AC INPUT

FOR BROWN OUT < 20ms

280V

LOW

LOW

250V(Min)

INPUT VOLTAGE

OUTPUT VOLTAGE

PFW

LD ENABLE

BROWN OUT

FOR BROWN OUT > 20ms

Load

Disabled

Charging of

Output Capacitor

315V for Vadj to 76%

(390V for Vadj to 100%)

290V for Vadj to 76%

(380V for Vadj to 100%)

After a Brown Out condition where the output voltage has not dropped below 250Vdc, the module will recover when input

power is restored. The PFW signal can be used to monitor input power loss.