AK4645AEZ Datasheet, PDF (33/85 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP-AMP

[AK4645A]
■ Digital EQ/HPF/LPFճ࿏
AK4645AͰ͸A/Dมޙ׵ͷσʔλʹରͯ͠ɺ෩੾ΓԻϑΟϧλɺεςϨΦڧײௐɺήΠϯิਖ਼ͼٴALCͷॲ
ཧΛߦ͏͜ͱ͕Ͱ͖·͢(Figure 28)ɻFIL1, FIL3, EQ͸ͦΕͧΕ1࣍ͷIIRϑΟϧλͰɺϑΟϧλ܎਺Λ೚ҙʹ
ઃఆͰ͖·͢ɻALCʹ͍ͭͯ͸ɺ “ALCಈ࡞”ͷ߲Λࢀরͯ͠Լ͍͞ɻ
DACͷΈಈ࡞ͤ͞Δ৔߹ɺ࠶ੜύεʹରͯ͠Digital EQ/HPF/LPFճ࿏͕ಈ࡞͠·͢ɻADCͷΈಈ࡞ͤ͞Δ৔
߹·ͨ͸ADCͱDACΛ྆ํಈ࡞ͤ͞Δ৔߹Ͱ͸࿥Իύεʹରͯ͠ಈ࡞͠·͢ɻ࿥Ի͔Β࠶ੜʹ੾Γସ͑ͨ৔
߹ɺ࿥Ի࣌ͷઃఆ͕อ࣋͞Ε͍ͯΔͷͰɺDigital EQ/HPF/LPFΛ࢖༻͠ͳ͍৔߹͸FIL3, EQ, FIL1, GN1-0 bits
Λ “0”ʹઃఆͯ͠Լ͍͞ɻ
PMADL bit, PMADR bit PMDAC bit LOOP bit
ঢ়ଶ
Digital EQ/HPF/LPF
“00”
0
x
ύϫʔμ΢ϯ
ύϫʔμ΢ϯ
1
x
࠶ੜ
࠶ੜύε
0
x
à¿¥Ô»
࿥Իύε
“01”, “10” or “11”
1
0
࿥Ի, ࠶ੜ
1
࿥ԻϞχλʔ࠶ੜ
࿥Իύε
࿥Իύε
Note 38. εςϨΦڧײௐճ࿏͸εςϨΦಈ࡞ͷͱ͖ͷΈ༗ޮͰ͢ɻ
Table 18. Digital EQ/HPF/LPFճ࿏ಈ࡞ઃఆ (x: Don’t care)
(default)
εςϨΦڧײௐͷATT͸FIL3ͷ܎਺Ͱಉ࣌ʹઃఆ͠·͢ɻ
ήΠϯิਖ਼ͷήΠϯ͸GN1-0 bits (Table 19)ͱEQͷ܎਺ͷ૊Έ߹ΘͤͰઃఆ͠·͢ɻ
FIL1, FIL3͸ͦΕͧΕF1AS, F3AS bits͕ “0”ͷͱ͖HPFʹͳΓɺF1AS, F3AS bits͕ “1”ͷͱ͖LPFʹͳΓ·͢ɻ
FIL3ΛOFF(MUTE)͠ɺEQ, FIL1Λ0dBͰεϧʔͤ͞Δ৔߹͸ɺͦΕͧΕFIL3, EQ, FIL1 bitsΛ “0”ʹઃఆͯ͠
Լ͍͞ɻ֤ϑΟϧλ܎਺Λॻ͖͑׵Δ৔߹͸ɺҰ౓εϧʔ(FIL3͸MUTE)ͷϞʔυʹ͔ͯ͠ΒߦͬͯԼ͍͞ɻ
MIX bit = “1”ͷ৔߹͸ɺFIL1ͷΈ࢖༻Ͱ͖·͢ɻEQ=FIL3 bits = “0”ʹઃఆͯ͠Լ͍͞ɻ
෩੾ΓԻϑΟϧλ
FIL1
܎਺೚ҙ
F1A13-0
F1B13-0
F1AS
εςϨΦڧײௐ
FIL3
܎਺೚ҙ
F3A13-0
F3B13-0
F3AS
0dB ∼ -10dB
MUTE
(FIL3 _{܎਺Ͱઃఆ})
ήΠϯิਖ਼
EQ
Gain
ALC
܎਺೚ҙ
EQA15-0
EQB13-0
EQC15-0
+12dB ∼ 0dB
GN1-0
+24/+12/0dB
Figure 28. Digital EQ/HPF/LPF
GN1
GN0
Gain
0
0
0dB
(default)
0
1
+12dB
1
x
+24dB
Table 19. Gain෦ͷήΠϯઃఆ (x: Don’t care)
MS0986-J-00
- 33 -
2008/07