FAN6756 Fairchild Semiconductor, FAN6756 Datasheet - Page 3

• Manufacturer Part Number: FAN6756
• Manufacturer: Fairchild Semiconductor

© 2011 Fairchild Semiconductor Corporation
FAN6756 • Rev. 1.0.4
Marking Information
Pin Configuration
Pin Definitions
Pin #
1
2
3
4
5
6
7
8
ZXYTT
6756ML
TPM
SENSE
Name
GATE
GND
VDD
NC
HV
RT
FB
Ground Pin. Placing a 0.1µF decoupling capacitor between VDD and GND is recommended.
Feedback Pin. The output voltage feedback information from the external compensation circuit is
fed into this pin. The PWM duty cycle is determined by comparing the FB signal with the current-
sense signal from the SENSE pin.
No Connection
High-Voltage Startup. The HV pin is typically connected to the AC line input through two external
diodes and one resistor (R
startup, but also to sense the line voltage. The line voltage information is used for brownout
protection and power limit line compensation. This pin also is used to intelligently discharge the
EMI filter capacitor when the removal of the AC line voltage is detected.
Over-Temperature Protection. An external NTC thermistor is connected from this pin to the GND
pin. Once the voltage of the RT pin drops below the threshold voltage, the controller latches off
the PWM. The RT pin also provides external latch protection. If the RT pin is not connected to
the NTC resistor for over-temperature protection, it is recommended to place a 100kΩ resistor to
ground to prevent noise interference.
Current Sense. The sensed voltage is used for Peak-Current-Mode control, short-circuit
protection, and cycle-by-cycle current limiting.
Power Supply of IC. Typically a hold-up capacitor connects from this pin to ground. A rectifier
diode, in series with the transformer auxiliary winding, connects to this pin to supply bias during
normal operation.
Gate Drive Output. The totem-pole output driver for the power MOSFET; internally limited to
V
GATE-CLAMP
.
Figure 4. Pin Configuration (Top View)
ZXYTT
6756MR
TPM
GND
NC
HV
FB
HV
Figure 3. Top Mark
). This pin is used, not only to charge the V
1
2
3
4
SOP-8
3
Description
8
7
6
5
F - Fairchild Logo
Z - Plant Code
X - 1-Digit Year Code
Y - 1-Digit Week Code
TT - 2-Digit Die Run Code
T - Package Type (M=SOP)
P - Y: Green Package
M - Manufacture Flow Code
SENSE
GATE
VDD
RT
DD
capacitor during
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