AK4631 Datasheet, PDF (39/69 Pages) Asahi Kasei Microsystems – 16-Bit Mono CODEC with ALC & MIC/SPK-AMP

ASAHI KASEI
[AK4631]
„ SPK – ALC ಈ࡞
ALC2 bit = “1”ͷ࣌ɺALC2ϒϩοΫʹΑΓɺεϐʔΧग़ྗͷALCಈ࡞͕ߦΘΕ·͢ɻALC2ͷೖྗΠϯϐʔμ
ϯε(MIN pin)͸typ. 24kΩͰVCOMిѹʹόΠΞε͞Ε͍ͯ·͢ɻALC2ͷϨϕϧμΠΞάϥϜʹ͍ͭͯ͸ɺ
Figure 36 ~ Figure 39 Λࢀরͯ͠Լ͍͞ɻ
ALC2Ϧϛολݕग़Ϩϕϧ͸SVDDిѹʹൺྫ͠ɺ–7.1dBV(@SPKG1 bit = “0”, SVDD=3.3V ·ͨ͸ SPKG1 bit =
“1”, SVDD=5V)ΑΓେ͖͍৴߸͕ೖྗ͞ΕΔͱALC2ճ࿏͕ಈ࡞͠ɺग़ྗϨϕϧΛ੍͢·͠ݶɻ࿈ଓͯ͠
−7.1dBVҎ্ͷ৴߸͕ALC2ճ࿏ʹೖྗ͞Εͨ৔߹ɺALC2Ϧϛολಈ࡞ͷมߋपظ͸250µs (=2/fs@fs=8kHz)
Ͱɺ0.5dBݮͭͣਰ͞Ε·͢ɻ
ALC2ϦΧόϦಈ࡞͸ৗʹθϩΫϩεݕग़ಈ࡞Λߦ͍ͳ͕Β1dBεςοϓͰ૿෯ͯ͠ߦ͖·͢ɻ͜ͷALC2Ϧ
ΧόϦಈ࡞͸ɺALC2 ͷग़ྗϨϕϧ͕ –9.1dBV(@SPKG1 bit = “0”, SVDD=3.3V ·ͨ͸ SPKG1 bit = “1”,
SVDD=5V)ʹͳΔ·Ͱߦ͍·͢ɻ·ͨɺALC2ϦΧόϦಈ࡞࣌ͷ࠷େήΠϯ͸ RFS5-0 bits Ͱઃఆ͠·͢ɻ
–9.1dBV ∼ –7.1dBVͷؒͷ৴߸͕ೖྗ͞Εͨ৔߹ɺALC2ϦϛολͼٴϦΧόϦಈ࡞͸ߦ͍·ͤΜɻ
PMSPK bitΛ“0”͔Β“1”ʹมߋ͢ΔͱɺॳظԽαΠΫϧ(512/fs=64ms @ fs=8kHz, ROTM bit = “0”)͕։࢝͞Ε·
͢ɻॳظԽαΠΫϧதɺALC2͸σΟηʔϒϧঢ়ଶʢALC2ͷήΠϯ͸ “–3.5dBݻఆ”ʣͰɺॳظԽαΠΫϧ͕
ऴྃ͢ΔͱALC2͸ “–2dB”͔Βಈ࡞Λ։࢝͠·͢ɻROTM bit ͓Αͼ RFS5-0 bits ͷઃఆ͸PMSPK = “0”ͷؒʹ
ߦͬͯԼ͍͞ɻ
ALC2 ͕Disableͷ৔߹ɺALC2ϒϩοΫͷήΠϯ͸ –3.5dBݻఆʹͳΓ·͢ɻै͍·ͯ͠ɺεϐʔΧϒϩοΫ
಺෦(MIN Æ SPP/SPN)ͷήΠϯ͸ɺTable 22 ʹࣔ͢Α͏ʹͳΓ·͢ɻ
ύϥϝʔλ
ALC2Ϧϛολಈ࡞
ALC2ϦΧόϦಈ࡞
ಈ࡞։࢝Ϩϕϧ
–7.1dBV
–9.1dBV
มߋप ظ^fs=8kHz
fs=16kHz
θϩΫϩεݕग़
2/fs = 250µs
2/fs = 125µs
ͳ͠
512/fs = 64ms
512/fs = 32ms
͋Γ (Timeout=512/fs)
ATT/GAINྔ
0.5dB step
1dB step
Table 21. Limiter /Recovery of ALC2 (ROTM bit = “0”)
SPKG1-0 bits
ήΠϯ
00
+4.4dB
01
+6.4dB
10
+10.6dB
11
+12.7dB
Table 22. ALC2 OFF ࣌ͷSPK-Amp(Full-differentialग़ྗ࣌)ήΠϯ
MS0317-J-01
- 39 -
2004/11