FSCQ-SERIES
FSCQ0765RT Typical Application Circuit
Application
Output Power
Input Voltage
Output Voltage (Max Current)
12V (1A)
18V (0.5A)
125V (0.4A)
24V (0.5A)
Universal input
(90-270Vac)
C-TV
83W
Features
• High Efficiency (>83% at 90Vac Input)
• Wider Load Range through the Extended Quasi-Resonant Operation
• Low Standby Mode Power Consumption (<1W)
• Low Component Count
• Enhanced System Reliability Through Various Protection Functions
• Internal Soft-Start (20ms)
Key Design Notes
• 24V output is designed to drop to around 8V in standby mode
1. Schematic
T1
D205
EER3540
EGP20D
12V, 1.0A
18V, 0.5A
125V, 0.4A
24V, 0.5A
10
11
RT101
5D-9
1
3
C204
1000uF
35V
C210
470pF
1kV
C102
220uF
400V
D204
EGP20D
BEAD101
R102
150kΩ
0.25W
R101
100kΩ
0.25W
4
13
12
C205
1000uF
35V
C107
1nF
1kV
BD101
C209
470pF
1kV
R106 C104
1.5kΩ 10uF
1W
D102
1N4937
D104
1
50V
UF4007
Drain
D202
EGP20J
SYNC
ZD101
18V
1W
3
Vcc
5
IC101
FSCQ0765RT
6
R104
1.5kΩ
0.25W
R103
5.1Ω
0.25W
D103
14
15
D101
1N4937
L201
BEAD
C202
47uF
160V
GND FB
C201
100uF
160V
1N4148
C207
470pF
1kV
2
4
16
C105
3.9nF
50V
C103
10uF
50V
R105
470Ω
0.25W
C106
47nF
50V
D203
EGP20D
17
18
7
C203
1000uF
35V
C208
470pF
1kV
LF101
VR201
30kΩ
R205
220kΩ
0.25W
R201
1kΩ
0.25W
OPTO101
FOD817A
Normal
ZD202
5.1V
0.5W
R202
1kΩ
0.25W
C101
330nF
275VAC
R208
1kΩ
SW201
Standby
R207
5.1kΩ
0.25W
FUSE
250V
2.0A
ZD201
0.25W
C206
22nF
50V
R203
39kΩ
0.25W
D201
Q202
KSC945
R206
5.1kΩ
0.25W
C301
2.2nF
R204
Q201
4.7kΩ
KA431
0.25W
23
FAIRCHILD [ FAIRCHILD SEMICONDUCTOR ]
