Samsung LW32A23W Service Manual page 10

Main Board Supply &Sound Exclusive IC of STR-W6853
Outlines
1. A new 7 Pin package has been developed from the existing 5 Pin package. High-power MOSFET is
embedded in a small package to save space.
2. The distance between the pins of MOSFET drain & source has been widened to 1.8mm where high
voltage is applied,allowing the loading of high anti-pressure MOSFET.
3. The operation mode changes in 3 stages according to the load applied, and saves power consumption.
TFC, MBS, and pseudo-oscillation are available.
Features
1. Improvement of power efficiency through automatic conversion of operation modes the controlling MIC
part saves power consumption through a BCD processor. W6800 series changes the operation mode in 3
stages according to the load applied and saves power consumption.
1) Pseudo-oscillation under load
2) If MBS (Multi, Bottom, Skip) frequency exceeds 70 kHz under medium or small loads, the bottom is
skipped while bottom, ON is maintained.
3) If TFC (Time, Fix, Control)operation extends the ON time forcibly under St-By load, the OFF time is
controlled to lower the oscillating frequency. In the event of compulsory ON, control by external
resistors is possible.
2. Major Features
1) Embedded overcurrent protection (OCP) of pulse by pulse
2) Embedded overload protection (OLP) of latch shut down.
3) Embedded thermal shutdown function.
4) Embedded overvoltage protection for input voltage
5) Adjustable frequency for TFC operation
LW32A23W/LW40A23W
Block Diagrams