Datasheet

www.ti.com
Current Calculations
OUT (max)
OUT (max)
OUT
P
I
V
=
350
0 9
390
OUT (max)
W
I . A
V
= @
OUT (max)
IN _ RMS(max)
IN (min)
P
I
V PFh
=
350
4 52
0 92 85 0 99
IN _ RMS(max)
W
I . A
. V .
= =
´ ´
2
IN _ PEAK (max) IN _ RMS(max)
I I=
2 4 52 6 39
IN _ PEAK (max)
I . A . A= ´ =
2
IN _ PEAK (max)
IN _ AVG(max)
I
I
p
=
2 6 39
4 07
IN _ AVG(max)
. A
I . A
p
´
= =
Bridge Rectifier
2
BRIDGE F _ BRIDGE IN _ AVG(max)
P V I=
2 0 95 4 07 7 73
BRIDGE
P . V . A . W= ´ ´ =
UCC28019
SLUS755B – APRIL 2007 – REVISED DECEMBER 2007
First, determine the maximum average output current, I
OUT(max)
:
The maximum input RMS line current, I
IN_RMS(max)
, is calculated using the parameters from Table 1 and the
efficiency and power factor initial assumptions:
Based upon the calculated RMS value, the maximum peak input current, I
IN_PEAK(max)
, and the maximum average
input current, I
IN_AVG(max)
, assuming the waveform is sinusoidal, can be determined.
Assuming a forward voltage drop, V
F_BRIDGE
, of 0.95 V across the rectifier diodes, BR1, the power loss in the
input bridge, P
BRIDGE
, can be calculated:
26 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated
Product Folder Link(s): UCC28019