FSQ0765RS Fairchild Semiconductor, FSQ0765RS Datasheet - Page 4

• Manufacturer Part Number: FSQ0765RS
• Description: A Quasi-Resonant Converter (QRC) generally shows lower EMI and higher power conversion efficiency than a conventional hard-switched converter with a fixed switching frequency
• Manufacturer: Fairchild Semiconductor

FSQ0765RS • Rev. 1.0.2
© 2008 Fairchild Semiconductor Corporation
Pin Configuration
Pin Definitions
Pin #
1
2
3
4
5
6
Name
Drain
GND
Sync
V
V
FB
CC
str
SenseFET drain. High-voltage power SenseFET drain connection.
Ground. This pin is the control ground and the SenseFET source.
Power Supply. This pin is the positive supply input, providing internal operating current for
both startup and steady-state operation.
Feedback. This pin is internally connected to the inverting input of the PWM comparator. The
collector of an opto-coupler is typically tied to this pin. For stable operation, a capacitor should
be placed between this pin and GND. If the voltage of this pin reaches 6V, the overload pro-
tection triggers, which shuts down the FPS.
Sync. This pin is internally connected to the sync-detect comparator for quasi-resonant switch-
ing. In normal quasi-resonant operation, the threshold of the sync comparator is 1.2V/1.0V.
Startup. This pin is connected directly, or through a resistor, to the high-voltage DC link. At
startup, the internal high-voltage current source supplies internal bias and charges the exter-
nal capacitor connected to the V
disabled. It is not recommended to connect V
FSQ0765R Rev.00
Figure 3. Pin Configuration (Top View)
CC
4
pin. Once V
Description
str
CC
and Drain together.
6. V
5. Sync
4. FB
3. V
2. GND
1. Drain
reaches 12V, the internal current source is
str
CC
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