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AK4495SEQ Datasheet, PDF (52/58 Pages) Asahi Kasei Microsystems – Quality-oriented Premium 32-Bit 2ch DAC | |||
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Digital Ground
System
Controller
Analog Ground
[AK4495S]
34 AOUTLP
35 VCOML
36 VREFLL
37 VREFLL
38 VREFHL
39 VREFHL
40 AVDD
41 AVSS
42 MCLK
43 DVSS
44 DVDD
AK4495SEQ
AOUTRP 22
VCOMR 21
VREFLR 20
VREFLR 19
VREFHR 18
VREFHR 17
ACKS/CAD1 16
DEM1 15
DEM0 14
I2C 13
PSN 12
1. ã°ã©ã³ãã¨é»æºã®ãã«ãããªã³ã°
Figure 29. Ground Layout
AK4495Sã§ã¯ãã£ã¸ã¿ã«ãã¤ãºã®ã«ãããªã³ã°ãæå°éã«æãããããAVDD, VDDL/R ã¨DVDDããã«
ãããªã³ã°ãã¾ããAVDD, VDDL/R ã«ã¯ã·ã¹ãã ã®ã¢ããã°é»æºãä¾çµ¦ããDVDDã«ã¯ã·ã¹ãã ã®ãã£
ã¸ã¿ã«é»æºãä¾çµ¦ãã¦ä¸ãããAVDD, VDDL/R ã¨DVDDã®é
ç·ã¯ã¬ã®ã¥ã¬ã¼ã¿çããã®ä½ã¤ã³ãã¼ãã³
ã¹ç¶æ
ã®ã¾ã¾åãã¦é
ç·ãã¦ä¸ããããã®éãAVDD, VDDL/R ã¨DVDDã®ç«ã¡ä¸ãã·ã¼ã±ã³ã¹ãèæ
®ã
ãå¿
è¦ã¯ããã¾ãããAVSS, DVSS, VSSL, VSSR ã¯åãã¢ããã°ã°ã©ã³ãã«æ¥ç¶ãã¦ä¸ããããã«ãããª
ã³ã°ã³ã³ãã³ãµãç¹ã«å°å®¹éã®ã»ã©ããã¯ã³ã³ãã³ãµã¯AK4495Sã«ã§ããã ãè¿ã¥ãã¦æ¥ç¶ãã¾ãã
2. åºæºé»å§
VREFHL/R pinã¨VREFLL/R pinã«å
¥åãããé»å§ã®å·®ãã¢ããã°åºåã®ãã«ã¹ã±ã¼ã«ã決å®ãã¾ããé常
ã¯VREFHL/R pinãAVDDã«æ¥ç¶ããVREFLL/R pinãVSS ã«æ¥ç¶ãã¾ããVREFHL/R pinã¨VREFLL/R pin
ã¨ã®éã«0.1µFã®ã»ã©ããã¯ã³ã³ãã³ãµãæ¥ç¶ãã¾ããVCML/Rã¯ã¢ããã°ä¿¡å·ã®ã³ã¢ã³é»å§ã¨ãã¦ä½¿ã
ãã¾ãããã®ãã³ã«ã¯é«å¨æ³¢ãã¤ãºãé¤å»ããããã«ã10µFç¨åº¦ã®é»è§£ã³ã³ãã³ãµã¨ä¸¦åã«0.1µFã®ã»ã©
ããã¯ã³ã³ãã³ãµãVSS ã¨ã®éã«æ¥ç¶ãã¦ä¸ãããç¹ã«ãã»ã©ããã¯ã³ã³ãã³ãµã¯ãã³ã«ã§ããã ãè¿
ã¥ãã¦æ¥ç¶ãã¦ä¸ãããVCML/R pinããé»æµãåã£ã¦ã¯ããã¾ããããã£ã¸ã¿ã«ä¿¡å·ãç¹ã«ã¯ããã¯ã¯
AK4495Sã¸ã®ã«ãããªã³ã°ãé¿ããããVREFHL/R, VREFLL/R pinããã§ããã ãé¢ãã¦ä¸ããã
3. ã¢ããã°åºå
ã¢ããã°åºåã¯å®å
¨å·®ååºåã«ãªã£ã¦ãããåºåã¬ã³ã¸ã¯AVDD/2ãä¸å¿ã«2.8Vpp (typ, VREFHL/R ï
VREFLL/R = 5V)ã§ããå·®ååºåã¯å¤é¨ã§å ç®ããã¾ããAOUTL/R +, AOUTL/R ïã®å ç®é»å§ã¯VAOUT =
(AOUT+)ï(AOUTï)ã§ããå ç®ã²ã¤ã³ãï¼ã®å ´åãåºåã¬ã³ã¸ã¯5.6Vpp (typ, VREFHL/R ï VREFLL/R = 5V)
ã§ããå¤é¨å ç®åè·¯ã®ãã¤ã¢ã¹é»å§ã¯å¤é¨ã§ä¾çµ¦ãã¾ããå
¥åã³ã¼ãã®ãã©ã¼ãããã¯2âs complement (2
ã®è£æ°)ã§7FFFFFH(@24bit)ã«å¯¾ãã¦ã¯æ£ã®ãã«ã¹ã±ã¼ã«ã800000H(@24bit) ã«å¯¾ãã¦ã¯è² ã®ãã«ã¹ã±ã¼
ã«ã000000H(@24bit)ã§ã®VAOUTã®çæ³å¤ã¯0Vé»å§ãåºåããã¾ãã
å
èµã®ïïå¤èª¿å¨ã®å¸¯åå¤ãã¤ãº(ã·ã§ã¼ãã³ã°ãã¤ãº)ã¯å
èµã®ã¹ã¤ããããã£ãã·ã¿ãã£ã«ã¿(SCF)ã§æ¸
è¡°ããã¾ãã
Figure 30ã¯å·®ååºåã1åã®ãªãã¢ã³ãã§å ç®ããå¤é¨LPFåè·¯ä¾ã§ããFigure 31ã¯å·®ååºåã®åè·¯ä¾å
ã³3åã®ãªãã¢ã³ãã使ã£ãå¤é¨LPFåè·¯ä¾ã§ãã
MS1560-J-01
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2013/11
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