Datasheet

UCC28C40, UCC28C41, UCC28C42, UCC28C43, UCC28C44, UCC28C45
UCC38C40, UCC38C41, UCC38C42, UCC38C43, UCC38C44, UCC38C45
SLUS458E -- AUGUST 2001 -- REVISED OCTOBER 2010
10
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APPLICATION INFORMATION
R28 100
D3
BAR74
C26
2uF
D5
BAR74
R14
20k 40%
C16
5.6nF
+
C15 1uF
C14 1uF
C13
0.22uF
C12
3300pF
C11
1500pF
D6
BZX84C15LT1
UCC38C4x
1
COMP
2
FB
3
CS
4
Rt/Ct
5
GND
6
OUT
7
Vcc
8
REF
U2
C22
4.7nF
C23 680pF
C24
0.1uF
C10
2.7nF
1 2
3 4
T2
Q4
Q3
L1
4.7uH
C21
0.1uF
+
C20
470uF
+
C19
470uF
3r3V PWRGND
D2
C2 1nF
C18
4700pF
C25
0.047uF
VinN VinP
C9
0.1uF
ucc3961
4
FB
5
Rt
6
Ref
7
AGnd
8
Vs
9
CS
10
PGnd
11
Out
1
OVS
2
SD
3
SS
12
Vdd
13
St
14
UVS
U1
+
C1
470uF
C3 10nF
C4
0.22uF
C5
0.1uF
C6
470pF
C7
100pF
C8
1uF
C17
4700pF
D1
Q1
Q2
TPS2832
8
BOOT
1
IN
6
BTLO
3
DT
7
HIDR
4
Vcc
2
PGND
5
LODR
U4
T1
R19
20
R22 100
R18
7.5k
R17 20k
R16
21.5k
R15
50k
R23 402
R24
20k
R25
20k
R12
200
R13
300
R27
4.7
R26
4.7
R7
10k
R21
10
R1 32.4k R2
1.2k
R3
2.4k
R4
1.5k
R5
76.8k
R6
4.7
R8
5.1k
R9
0.33
R10
1k
R11
46.4k
R20
10
Figure 5. Forward Converter with Synchronous Rectification Using the UCC38C42
as the Secondary-Side Controller