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AK4141 Datasheet, PDF (26/96 Pages) Asahi Kasei Microsystems – NICAM/A2/EIA-J Digital Stereo Decoder | |||
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[AK4141]
â ALCåä½
1. ALCãªããã¿åä½
ALCãªããã¿åä½ã§ã¯Lch, Rchã®åºåã¬ãã«ã®ã©ã¡ããä¸æ¹ã§ãALCãªããã¿æ¤åºè¨å®ã¬ãã«(Table 11)ãè¶ããå ´åã
LMAT1-0 bitã§è¨å®ããå¤(Table 12)ã ããVOLå¤(L/Rå
±é)ãèªåçã«æ¸è¡°ããã¾ãããã®ã¨ãVOLå¤ã®å¤æ´ã¯L/R
å
±éã§è¡ããã¾ãã
ZELMN bit = â0â(ã¼ãã¯ãã¹æ¤åºæå¹)ã®ã¨ããALCãªããã¿åä½ã«ããVOLå¤ãå¤æ´ãããã®ã¯ãL/Rç¬ç«ã«
ããããã¼ãã¯ãã¹ãããã¼ãã¯ãã¹ã¿ã¤ã ã¢ã¦ãããã¨ãã§ããã¼ãã¯ãã¹ã¿ã¤ã ã¢ã¦ãæéã¯ZTM1-0
bitã«ã¦è¨å®ã§ãã¾ã(Table 13)ã
ZELMN bit = â1â(ã¼ãã¯ãã¹æ¤åºç¡å¹)ã®ã¨ããALCãªããã¿åä½ã«ããVOLå¤ã¯ç¬æ(å¨æ: 1/fs)ã«å¤æ´ãã
ã¾ãããªããã¿åä½ã®æ¸è¡°éã¯LMAT1-0 bitã®è¨å®ã«ããããã1 stepåºå®ã§ãã
æ¸è¡°åä½çµäºå¾ã§ãALC bitã â0âã«ããªãéããåã³åºåã¬ãã«ãALCãªããã¿æ¤åºã¬ãã«ãè¶ããã°ããã®æ¸è¡°å
ä½ã¯ç¹°ãè¿ããã¾ãã
LMTH1
0
0
1
1
LMTH0 ALCãªããã¿æ¤åºã¬ãã« ALCãªã«ããªå¾
æ©ã«ã¦ã³ã¿ãªã»ããã¬ãã«
0
ALC Output ï³ ï2.5dBFS
ï2.5dBFS > ALC Output ï³ ï4.1dBFS
1
ALC Output ï³ ï4.1dBFS
ï4.1dBFS > ALC Output ï³ ï6.0dBFS
0
ALC Output ï³ ï6.0dBFS
ï6.0dBFS > ALC Output ï³ ï8.5dBFS
1
ALC Output ï³ ï8.5dBFS
ï8.5dBFS > ALC Output ï³ ï12dBFS
Table 11. ALC ãªããã¿æ¤åºã¬ãã«ï¼ãªã«ããªå¾
æ©ã«ã¦ã³ã¿ãªã»ããã¬ãã«
(default)
LMAT1
0
0
1
1
ALC1 ãªããã¿ATTã¹ããã
LMAT0 ALC1 Output ALC1 Output ALC1 Output ALC1 Output
ï³ LMTH
ï³ FS
ï³ FS + 6dB ï³ FS + 12dB
0
1
1
1
1
(default)
1
2
2
2
2
0
2
4
4
8
1
1
2
4
8
Table 12. ALC ãªããã¿ATTã¹ãããã®è¨å®
ZTM1
0
0
1
1
ZTM0
ã¼ãã¯ãã¹ã¿ã¤ã ã¢ã¦ãæé
32kHz
44.1kHz
48kHz
0
128/fs
4.0ms
2.9ms
2.7ms
1
256/fs
8.0ms
5.8ms
5.3ms
0
512/fs
16.0ms
11.6ms
10.7ms
1
1024/fs
32.0ms
23.2ms
21.3ms
Table 13. ALCã¼ãã¯ãã¹ã¿ã¤ã ã¢ã¦ãæéã®è¨å®
(default)
MS0952-J-03
- 26 -
2013/12
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