FAN7528 Fairchild Semiconductor, FAN7528 Datasheet - Page 3

• Manufacturer Part Number: FAN7528
• Description: Dual Output Critical Conduction Mode PFC Controller
• Manufacturer: Fairchild Semiconductor

FAN7528 Rev. 1.0.1
Pin Assignments
Pin Definitions
Pin Number Pin Name
1
2
3
4
5
6
7
8
COMP
MOT
GND
ZCD
OUT
INV
Vcc
CS
This pin is the inverting input of the error amplifier. The output voltage of the boost PFC converter
should be resistively divided to 2.5V at the high line condition and connected to this pin. If this
pin voltage is controlled to be lower than 0.45V, the device is disabled.
This pin is the output of the transconductance error amplifier. Some components for the output
voltage compensation should be connected between this pin and GND.
This pin is used to set the slope of the internal ramp. The voltage of this pin is maintained to be
1V. If a resistor is connected between this pin and GND, current flows out of the pin and the slope
of the internal ramp is proportional to this current.
This pin is the input of the over current protection comparator. The MOSFET current is sensed
using a sensing resistor and the resulting voltage is applied to this pin. An internal RC filter is
included to filter switching noise. This pin is sensitive to the negative voltage below -0.3V. For
proper operation, the stray inductance in the sensing path and the inductance of the sensing re-
sistor must be minimized.
This pin is the input of the zero current detection block. If the voltage of this pin goes higher than
1.5V and then goes lower than 1.4V, the MOSFET is turned on.
This pin is used for the ground potential of all the pins. For proper operation, the signal ground
and the power ground should be separated.
This pin is the gate drive output. The peak sourcing and sinking current level is 400mA. For prop-
er operation, the stray inductance in the gate driving path must be minimized.
This pin is the IC supply pin. IC current and MOSFET drive current are supplied using this pin.
Figure 3. Pin Configuration (Top View)
Vcc
INV
8
1
COMP
F A N
7 5 2 8
OUT
7
2
3
W W W
Pin Function Description
GND
MOT
6
3
ZCD
CS
5
4
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