- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄381126 > STV0056AF (意法半導(dǎo)體) Satellite Sound and Video Processor(衛(wèi)星探測和視頻處理器) PDF資料下載
參數(shù)資料
| 型號： | STV0056AF |
| 廠商： | 意法半導(dǎo)體 |
| 英文描述： | Satellite Sound and Video Processor(衛(wèi)星探測和視頻處理器) |
| 中文描述： | 衛(wèi)星聲音和視頻處理器（衛(wèi)星探測和視頻處理器） |
| 文件頁數(shù)： | 23/27頁 |
| 文件大?。?/td> | 224K |
| 代理商： | STV0056AF |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁當(dāng)前第23頁第24頁第25頁第26頁第27頁
FMDEMODULATION SOFTWARE ROUTINE
WiththeSTV0056AFcircuit,foreachchannel,three
stepsare required to acheivea FMdemodulation:
- 1
st
step:To set the demodulationparameters :
FM deviationselection,
Subcarrier frequencyselection.
- 2
nd
step : To implement a waiting loop to check
the actual VCO frequency.
- 3
rd
step:Toclosethedemodulationphaselocked
loop (PLL).
Refering to the FM demodulation block diagram
(page 12), the frequency synthesis block is com-
monto bothchannels(leftand right);consequently
twocompletesequenceshaveto bedoneoneafter
the other when demodulatingstereo pairs.
Detailed Description
Conventions:
- R = Stands for Register
- B = Stands for Bit
Example :
R05 B2 = Register05, Bit 2
For clarity, the explanationsare basedon the fol-
lowing example : stereo pair 7.02MHz/L
7.20MHz/R,deviation
±
50kHz max.
1stSTEP (LEFT) :
SETTINGTHE DEMODULATION PARAMETERS
A.
The FMdeviationis selectedby loadingR5 with
the appropriatevalue. (seeR5 truth table).
NB : Verywide deviations(up to
±
592kHz) can be
accomodatedwhen R5 B5 is low.
Corresponding bandwidth can be calculated as
follows :
Bw
≈
2 (FMdeviation+ audio bandwidth)
Bw
≈
2 (valuegiven in table + audio bandwidth)
In the example:
R5Bits 7
6
5
4
3
2
X
X
1
1
0
1
1
1
0
0
B.
The subcarrier
launchingafrequencysynthesis(theVCOis driven
to the wanted frequency).This operationrequires
twoactions :
- To connect the VCO to the frequency synthesis
loop.ReferingtotheFMblockdiagram(page12):
SW4 closed
R6 B2 = H
SW3 to bias
R6 B4 = L
SW2 to bias
R6 B3 = L
SW1 opened
R6B5 = L
- To load R7 and R6 B6 B7 with the value corre-
sponding to the left channel frequency. This 10
bits valueis calculatedas follows:
Subcarrierfrequency = codedvalue x 10kHz
(10kHz is the minimum step of the frequency
synthesis function)
Considering that the tunning range is comprised
between5to10MHz,thecodedvalueis anumber
between 500 and 1000 (2
10
= 1024)then 10 bits
are required.
Example :
7.02MHz = 702x 10kHz
702
1010 1111 10
AF + 10
R7 is loaded with AF and R6 B6 : L, R6 B7 : H.
frequency
is selected
by
The Table1 givesthesettingforthemostcommon
subcarrierfrequencies.
Table 1 :
FrequencySynthesisRegister Setting
for the Most CommonSubcarrierFrequencies
Subcarrier Frequency
(MHz)
Register 7
(Hex)
Register 6
Bit 7
1
0
0
1
0
1
0
0
1
0
0
0
0
1
0
0
1
0
1
0
0
0
0
Bit 6
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
1
0
0
0
1
0
0
1
5.58
5.76
5.8
5.94
6.2
6.3
6.4
6.48
6.5
6.6
6.65
6.8
6.85
7.02
7.20
7.25
7.38
7.56
7.74
7.85
7.92
8.2
8.65
8B
90
91
94
9B
9D
A0
A2
A2
A5
A6
AA
AB
AF
B4
B5
B8
BD
C1
C4
C6
CD
D8
STV0056AF
23/27
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| STV0056A | Satellite Sound and Video Processor(衛(wèi)星探測和視頻處理器) |
| STV0297JT | Universal digital cable demodulator |
| STV0297J | Universal digital cable demodulator |
| STV0297J-TMM | Universal digital cable demodulator |
| STV0299B | QPSK/BPSK LINK IC |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| STV0116 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Color Encoder Circuit |
| STV0116FN | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Color Encoder Circuit |
| STV0117 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Color Encoder Circuit |
| STV0117A | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Color Encoder Circuit |
| STV0118 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:PAL/NTSC HIGH PERFORMANCE DIGITAL ENCODER |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。