Power integrations InnoSwitch3 - Page 31

Rev. A 10/18
31
Application NoteAN-72
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RC Network Across RFB
UPPER
In some applications where low output
ripple voltage is required, it is necessary to
speed up the feedback sensing by adding
an RC phase-boost network circuit in
parallel with upper feedback resistor. A
good starting value is 1 nF and 1 kΩ.
Diode Across SR FET
Putting a Schottky diode across the SR FET
may further increase efciency by 0.1 to
0.2% depending on the input and the
SR FET used.
Capacitor Across OUTPUT VOLTAGE-
GROUND Pins
Putting a small ceramic capacitor (up to
10 µF) from OUTPUT VOLTAGE to
GROUND pins can reduce output ripple
PI-8473-100417
Secondary
Control IC
R
IS
Primary FET
and Controller
D V
S IS
VOUT
BPS FB
GND
SR
BPP
FWD
InnoSwitch3
SR FET
C
F
R
F
PI-8470-100417
Secondary
Control IC
SR FET
R
IS
Primary FET
and Controller
D V
S IS
VOUT
BPS FB
GND
SR
BPP
FWD
InnoSwitch3
Diode
Figure 25 (cont.). Circuit Ideas to Enhance Design.
PI-8472-100417
Secondary
Control IC
R
IS
Primary FET
and Controller
D V
S IS
VOUT
BPS FB
GND
SR
BPP
FWD
InnoSwitch3
C
VOUT