Analog Board - Philips DVDR5350H/02 Service Manual

9.2. Front Board (Panel – Display + Key)
9.2.1. General
This board consists of the following parts:
• μP driver for the FTD
•
Frontend (Audio & Video)
•
VFD Heater voltage Generator
9.2.2. μP (IC 7103 : TMP86CM74AFG)
The core element of the Front (Display + Key) board is the
μP [7103].
It runs on a 5V supply & a clock frequency of 16MHz, and is
responsible for the following functions:
• Interface with the Slave μP on the Analog board via I
bus
•
Driver for the FTD display [1203 : HUV-08SS65T]
9.2.3. VFD Heater Voltage Generator
Pin 12 of μP [7103] provides the necessary sine wave signal
out for transistor [7106, 7108 & 7109] to generate the 50%
duty-cycle 48KHz AC square-wave signal for the fi lament of
the FTD.
9.3.

Analog Board

9.3.1. General
The Analog board consists of the following parts:
• Slave μP
•
Fan Control
•
Simple Power Supply
•
Tuner Frontend
•
Audio ADC/DAC
9.3.2. Slave μP (IC 7108 : TMP87CH74F)
The slave μP which run on a 5V supply and is responsible for
the following functions:
•
Interface with the Chrysalis chip on the Digital Board via
I C interface, where it functions in the slave-mode
2
•
Evaluation of the keyboard matrix (network of resistors)
on the Front board via pin 32 and 33.
•
Decoding the remote control commands from the infra-red
receiver on the Front board via pin 22.
•
Activation and control of the FTD display on the Front
board (with the help of 7103 as driver) via I
•
Timer Wake-up activation
•
Fan control via transistors 7104 and 7105
It runs on two clock frequencies namely:
•
8MHz for normal operation
•
32.768KHz for the real time clock
9.3.3. Timer Wake-up activation
During the Standby mode, the slave μP provides a wakeup
call (STBY-line switches to high) to the PSU Board switching
on the Digital Board.
Circuit- and IC description
9.3.4. Simple Power Supply
The main power supply for this set is generated in the PSU
board. Within the Analog board only the 5V, 3V3SW and
8VSTBY lines are generated.
Below are the supply lines from the Simple Power supply on
the Analog board:
•
•
•
•
•
•
•
•
2 C
•
Standby modes:
In Standby mode the STBY control line is low, switching off
the 3V3D, 5VD, 5ND and 12VE supply and thus reducing the
power consumption.
9.3.5. Tuner Frontend [1700 : TMQZ2-439A]
It has a RF IN for antenna connection and RF OUT which
provides a RF loop through for connection to the TV.
The Frontend ( Tuner & IF-demodulator ) is controlled by
I
Slave μP [7108].
Complete video processing is done in this unit and the video
output (CVBS) is taken out from the [VIDOUT] pin 17 via
a transistor [7100] as VFV-line to the Video I/O circuitry. The
audio-IF component SIF1 is taken out from the [SIFOUT]
pin 7 for the demodulation by the Multi-sound processor
(MSP).
Audio demodulator
The sound demodulation is done by the MSP3415 [7600],
which is also fully controlled via I
audio signals are available at pin 26 and pin 27 and fed as
AFER- & AFEL- line to the audio I/O for further processing.
C bus
2
3139 785 31532
3V3SW to DAC_ADC and CU
3V3STBY to CU
5V to IOV, CU, PROG, MSP, DIGIO and FV
5NSTBY to IOA, PROG, DAC_ADC and Front board
5VSTBY to IOA, IOV, FV, CU, DAC_ADC and Front
Board
8VSTBY to MSP
12VSTBY to CU, IOV, DAC_ADC and Front Board
33VSTBY to FV
VGNSTBY to CU and Front Board
2 C (SCL_5V- and SDA_5V-) lines coming from the
9. EN 165
C bus by the Slave μP. The
2