Circuit Description; Power Supply - Samsung SPL4225X/XAA Service Manual

5. Circuit Description

5-1 Power supply

5-1-1 Outline(PDP SMPS)
Considering various related conditions, the switching regulator with good efficiency and allowing for its
small size and lightweight was used as the power supply for PDP. Most of the power supply components
used forward converter, and Vsamp and Vsb used simple flyback converter.
To comply with the international harmonics standards and improve the power factor, active PFC (Power
Factor Correction) was used to rectify AC input into +400V DC output, which in turns used as input to the
switching regulator.
5-1-2 42"SD SMPS SPECIFICATION
5-1-2(A) INPUT
PDP-42PS board is designed so that input power can be used within AC 90 VAC to 264 VAC with
50/60Hz ± 3Hz.
5-1-2(B) OUTPUT
PDP-42PS board provides 13 output switching power supplies for PDP 50inch (+165Vs, +220Set, +185Ve,
+75Va, +80Scan, +18Vg, +5Vsb, +5V(D), +5V(A), +12V. +9V, +12Vfan, and +12Vsamp). The output volt-
age, and current requirements for continuous operation are stated below (Table 3).
Output Name
Vs
Va
Vscan
Vset
Ve
Vg
Vfan
V9
V5(A)
V5(D)
Vsb
V12
Vsamp
Samsung Electronics
Table1. Specifications of Output Power Supplies for PDP SMPS
Output Voltage
+165V
+75V
+80V
+220V
+185V
+18.3V
+12V
+9V
+5V
+5.3V
+5V
+12V
+12V
Output Current
1.4A Sustain Voltage of Drive Board
0.5A Address Voltage of Drive Board
0.05A
0.05A
0.05A
0.3A
0.8A
0.3A
1.0A Analog IC Drive Voltage of Video Board
3.5A IC Drive Voltage of Logic Board
0.4 Stand-by for Remote Control
1.2A
1.5A
Circuit Operation Description
Using in PDP driving
5-1