Circuit Descriptions, Abbreviation List, and IC Data Sheets
9.
The application in this chassis is as follows:
•
I
2
C address 0x86.
•
Down conversion from IF to low-IF frequency (5.166 MHz
centre frequency).
•
Advanced filtering (for further rejection of adjacent
channels).
•
Gain to obtain optimised channel decoder level. Control
signal is coming from channel decoder.
SAW filter
X6874D and X3451K
•
Analogue sound for BG, I, DK, L, L’.
•
DVB-T (digital reception sound
and
video).
For digital reception, the application in this chassis is as
follows:
•
Rejection of adjacent channels.
•
Switching is done by Master IF (3 inputs).
•
One SAW covering both 7 and 8 MHz channels.
X6774D
•
Analogue video for BG, I, DK, L, L’.
Channel decoder (TDA10048) DVB-T
The channel decoder has the following specifications:
•
I
2
C address 0x10.
•
Decoding from low-IF to MPEG transport stream.
•
During decoding: de-modulation, de-interleaving and error
correction.
•
External clock buffer required.
•
No start-up requirements.
•
AGC monitor.
Channel decoder (TDA10023) DVB-C
The channel decoder has the following specifications:
•
I
2
C address 0x1C.
•
Decoding from low-IF to MPEG transport stream.
•
During decoding: de-modulation, de-interleaving and error
correction.
•
External clock buffer required.
•
No start-up requirements.
•
AGC monitor.
9.3.2
Digital signal processing (front-end)
Refer to figure “9-4 DVB-C signal broadcast reception block
diagram” and “9-5 DVB-T signal broadcast reception block
diagram” for details of digital signal processing.
Figure 9-4 DVB-C signal broadcast reception block diagram
DVB-T
TDA10048
10-bit
ADC
PLL
Decoding
TS
interface
C0h
Tuner
TD1716_Mk4
PLL
4MHz
HPF
7MHz
X3451K
36.13MHz
5,8MHz
37.6MHz
DVB-C
TDA10023
10-bit
ADC
PLL
Decoding
TS
interface
PNX8
5
4
1
Side Band
Filter
SIF AGC
Nyquist
Filter
VIF AGC
Band Pass
Filter
Sound
Trap
Group
Delay
TDA9898
PLL
TOP
PEAK AGC
L AGC
8MHz
36.125MHz
X6874D
RF
IF
DIF
LIF
SIF
CVBS
TS
IF
Wideband AGC
IF AGC
RF AGC
DVB-T
TDA10048
10-bit
ADC
PLL
Decoding
TS
interface
Tuner
TD1716_Mk4
PLL
4MHz
HPF
7MHz
X3451K
36.13MHz
5,8MHz
37.6MHz
DVB-C
TDA10023
10-bit
ADC
PLL
Decoding
TS
interface
PNX8
5
4
1
Side Band
Filter
SIF AGC
SIF AGC
Nyquist
Filter
Nyquist
Filter
VIF AGC
VIF AGC
Band Pass
Filter
Band Pass
Filter
Sound
Trap
Sound
Trap
Group
Delay
Group
Delay
TDA9898
PLL
TOP
PEAK AGC
L AGC
L AGC
8MHz
36.125MHz
8MHz
36.125MHz
X6874D
RF
IF
DIF
LIF
SIF
CVBS
TS
IF
Wideband AGC
IF AGC
RF AGC
T-AGC
T-AGC
I_17660_144.ep
s
170
3
0
8