Philips DVDR3350H Service Manual page 58

EN 58 8. 3139 785 30981
8.4.5. Power Supply
The Digital board is not powered in standby mode. The
control signal STBY on the analog board will enable the
PSU and power the digital board.
•
STBY = Low: the digital board is in powered down
standby mode
•
STBY = High: the power supply to the digital board is
enabled.
The 3V3, +5V and +12V come from the PSU, while the
following voltages are generated in the digital board:
•
1.8V core voltage is generated on the board by a 2A
switching step down voltage regulator [7521]
8.4.7. Reset
5V Supply
HOSTRST
POWER ON
RESET & LOW
VOLTAGE
DETECTION
NCP303LSN30
IC7595
Reset concept Digital board
The rest circuitry [7595] takes cares that the different
devices on the digital board are boot-up in the correct
order. At power on the reset circuitry provides the
following resets (delay τ1):
•
SYS_RST# to the Domino chip [7101] and Flash
Memory [7294]
The Domino chip then generates other reset signals
(delay τ2) via its GPIOs:
•
VID_RST# to reset the VIP [7401]
•
LINK_RST# to reset the IEEE1394 DV PHY IC [7301]
•
ODD_RST#_1 to reset Basic Engine
•
HDD_RST#_1 to reset the Hard Disk
Circuit- and IC Description
FRONT
MICROPROCESSOR
SYSRST#
FLASH MEMORY
Delay t
RSTn
Figure 8-6 DOMINO_RESET
•
2.5V supply for the SDRAM is generated by an ultra
fast low dropout linear regulator [7515]
•
1.25V DDR termination supply is generated by
regulator [7201]
8.4.6. Memory
•
FLASH IC7294: this memory contains the boot
parameters and application fi rmware
HDD_RST#_1
ODD_RST#_1
DMN 8652
1
Delay t
VID_RST#
VIP_RST#
LNK_RST#
1
8.4.8. I/O Connector
Audio IO Connector (item 1536)
The Audio In/Out (AIO) connector is used to interchange
digital audio signals between the Analog and Digital
board
Video IO Connector (item 1521)
The Video In/Out (VIO) Connector is used to interchange
analogue video signals between the Analog and Digital
board
Hard Disk
2
Delay t
Basic Engine
VAD8041
2
Delay t
VIP (TVP5146)
2
Delay t
PDI1394P25BD
2
Delay t