Philips 19PFL5522D Service Manual page 80

EN 80 9. LC7.2E LB
AUDIO CLASS D
9.2 Main Supply
The Main Power Supply Unit (PSU) in this chassis is a buy-in
"Jabil" supply unit and is a black-box for Service. When
defective, a new panel must be ordered and the defective panel
must be returned for repair, unless the main fuse of the unit is
broken. Always replace the fuse with one of the correct
specifications! This part is commonly available in the regular
market.
The Main Power Supply Unit delivers the following voltages to
the chassis:
• +12 V to SSB
• +12 V and -12 V to Audio Supply
• +5.2 V Standby voltage
• +3.3 V LVDS supply.
9.3 DC/DC converters
A switch generates the +5.2 V (+5V_SW) from the +5.2 V
(+5V_STANDBY) supply voltage. For LCD sets, this switch is
mounted on-board the SSB. This results in the +5V_STANDBY
voltage(s), coming from the Power Supply Unit, is (are) used as
input for the on-board DC/DC converters.
They deliver the following voltages to the board:
• +3.3 V (+3V3_STBY)
• +5.2 V (+5V_SW) (only for LCD sets)
• +1.8 V (+1V8S_SW)
• +34 V (+VTUN)
• +3.3 V (+3V3_SW)
• +3.3 V (+3V3_MOJO)
• +1.2 V (+1V2_MOJO)
An overview can be found in figure "DC-DC converter block
diagram".
Circuit Descriptions, Abbreviation List, and IC Data Sheets
MICRONAS
AUDIO PROC.
SDRAM
SDRAM
Figure 9-2 SSB bottom view
DC-DC CONVERSION
COMMON INTERFACE
CHANNEL
DECODER
Figure 9-3 DC-DC converter block diagram
The +5 V switch, needed for the switch voltages, is for LCD
sets physically mounted on the SSB.
G_16860_049.eps
310107
(n.a. for LC7.xH)
(n.a. for LC7.xH)
(n.a. for LC7.xH)
G_16860_063.eps
270707