LC-52X20E (serv.man5). Major IC Informations - Sharp TV Service Manual (repair manual). Page 23

LC-42XL2E/S/RU, LC-46XL2E/S/RU, LC-46X20E/S/RU, LC-52XL2E/S/RU, LC-52X20E/S/RU

5 – 23

1

INV

I

Inverting input of the error amplifier. The information on the output voltage of the PFC preregulator is fed 
into the pin through a resistor divider.

2

COMP

O

Output of the error amplifier. A compensation network is placed between this pin and INV (pin #1) to 
achieve stability of the voltage control loop and ensure high power factor and low THD.

3

MULT

I

Main input to the multiplier. This pin is connected to the rectified mains voltage via a resistor divider and 
provides the sinusoidal reference to the current loop.

4

CS

I

Input to the PWM comparator. The current flowing in the MOSFET is sensed through a resistor, the result-
ing voltage is applied to this pin and compared with an internal sinusoidal-shaped reference, generated by 
the multiplier, to determine MOSFET’s turn-off.

5

ZCD

I

Boost inductor’s demagnetization sensing input for transition-mode operation. A negative-going edge trig-
gers MOSFET’s turn-on.

6

GND

—

Ground. Current return for both the signal part of the IC and the gate driver.

7

GD

O

Gate driver output. The totem pole output stage is able to drive power MOSFET’s and IGBT’s with a peak 
current of 600 mA source and 800 mA sink. The high-level voltage of this pin is clamped at about 12V to 
avoid excessive gate voltages in case the pin is supplied with a high Vcc.

8

VCC

—

Supply Voltage of both the signal part of the IC and the gate driver. The supply voltage upper limit is 
extended to 22V min. to provide more headroom for supply voltage changes.

5

DRAIN (D) Pin:

Power MOSFET drain connection. Provides internal operating current for both start-up 
and steady-state operation.

1

BYPASS (BP) Pin:

Connection point for a 0.1 

µF external bypass capacitor for the internally generated 5.8 

V supply.

4

ENABLE/UNDER-VOLTAGE (EN/UV) 
Pin:

This pin has dual functions: enable input and line under-voltage sense. During normal 
operation, switching of the power MOSFET is controlled by this pin. MOSFET switch-
ing is terminated when a current greater than 240 

µA is drawn from this pin. This pin 

also senses line under-voltage conditions through an external resistor connected to the 
DC line voltage. If there is no external resistor connected to this pin, TinySwitch-II 
detects its absence and disables the line undervoltage function.

2,3

SOURCE (S) Pin:

Control circuit common, internally connected to output MOSFET source.