Dell 2208WFP Service Manual page 24

8.3 U850 ( , PWM Power Controller)
Pin Symbol
1 RT
2 COMP
3 CS
4 GND
5 OUT
6 VCC
7 NC
8 HV
8.4 U1 ( , CCFL Inverter controller IC)
Pin Symbol
1
2
3
4
5
6
7
8
I/O
I This pin is to program the switching frequency. By
connecting a resistor to ground to set the switching
frequency.
I Voltage feedback pin(same as the COMP pin in
UC384X).By connecting a photo-coupler to close the
control loop and achieve the regulation.
I Current sense pin, connect to sense the MOSFET current;
Ground
O Gate drive output to drive the external MOSFET
I Supply voltage pin
Unconnected pin
I Connect this pin to positive terminal of bulk capacitor the
startup current for the controller. When Vcc voltage trips
the UVLO(on),this HV loop will be off to save the power
loss on the startup circuit;
I/O
I
I
I
I
O
Ground
O
O
O
I
I
I
I
I
I
Enable/Disable
23
Description
Description
capacitor for Delay Timer
PWM Dimming Input
Service Manual