AK4631 Datasheet, PDF (51/69 Pages) Asahi Kasei Microsystems – 16-Bit Mono CODEC with ALC & MIC/SPK-AMP

ASAHI KASEI
[AK4631]
Addr
07H
Register Name
ALC Mode Control 1
Default
D7
D6
D5
D4
D3
D2
D1
D0
0
ALC2 ALC1 ZELM LMAT1 LMAT0 RATT LMTH
0
1
0
0
0
0
0
0


LMTH: ALC1Ϧϛολݕग़ઃఆϨϕϧ/ϦΧόϦ଴ػΧ΢ϯλϦηοτϨϕϧ(see Table 35)
ALC1Ϧϛολݕग़ઃఆϨϕϧͼٴϦΧόϦ଴ػΧ΢ϯλϦηοτϨϕϧͷ͹Β͖ͭ͸ͦΕͧΕ
(ઃఆ஋±2dB)Ͱ͢ɻॳظ஋͸“0”Ͱ͢ɻ


LMTH ALC1Ϧϛολݕग़Ϩϕϧ ALC1ϦΧόϦ଴ػΧ΢ϯλϦηοτϨϕϧ
0
ADC Input ≥ −6.0dBFS
1
ADC Input ≥ −4.0dBFS
−6.0dBFS > ADC Input ≥ −8.0dBFS
−4.0dBFS > ADC Input ≥ −6.0dBFS
Default
Table 35. ALC1 Limiter Detection Level / Recovery Waiting Counter Reset Level
RATT: ALC1ϦΧόϦήΠϯεςοϓ(see Table 36)
ALC1ϦΧόϦಈ࡞࣌ɺࡏݱͷIPGA஋͔Β૿Ճͤ͞Δεςοϓ਺Λઃఆ͠·͢ɻྫ͑͹ɺࡏݱͷ
IPGA஋͕30Hͷ৔߹ɺRATT bit=“1”ʹઃఆ͓ͯ͘͠ͱɺALC1ϦΧόϦಈ࡞ʹΑͬͯIPGA஋͸32H
ʹมߋ͞Εɺ1dB (=0.5 × 2)૿Ճ͞Ε·͢ɻ
IPGA஋͕ج४Ϩϕϧ(REF6-0 bit)ʹୡͨ͠৔߹ɺIPGA஋ͷ૿Ճ͸ߦ͍·ͤΜɻ


RATT
GAIN STEP
0
1
Default
1
2
Table 36. ALC1 Recovery Gain Step Setting
LMAT1-0: ALC1ϦϛολATTεςοϓ(see Table 37)
ALC1Ϧϛολಈ࡞࣌ɺೖྗ৴߸͕ઃఆ͞ΕͨALC1Ϧϛολݕग़Ϩϕϧ(LMTH)Λӽ͑ͨ৔߹ɺݱ
ࡏͷIPGA஋͔Βݮਰͤ͞Δεςοϓ਺Λઃఆ͠·͢ɻྫ͑͹ɺࡏݱͷIPGA஋͕47Hͷ৔߹ɺ
LMAT1-0 bit=“11”ʹઃఆ͓ͯ͘͠ͱɺALC1Ϧϛολಈ࡞ʹΑͬͯIPGA஋͸43Hʹมߋ͞Εɺ2dB
(=0.5 × 4)ݮਰ͞Ε·͢ɻ
ALC1Ϧϛολͷಈ࡞पظ͸ɺLTM1-0 bitͱZELM bitʹΑͬͯઃఆ͢Δ͜ͱ͕Ͱ͖·͢ɻ
ݮਰྔ͕IPGA=“00H”Λӽ͑ͨ஋ʹͳΔ৔߹ɺ“00H”ʹΫϦοϓ͞Ε·͢ɻ
LMAT1 LMAT0 ATT STEP
0
0
1
0
1
2
1
0
3
1
1
4
Table 37. ALC1 Limiter ATT Step Setting
Default
ZELM: ALC1Ϧϛολಈ࡞࣌θϩΫϩεݕग़Πωʔϒϧ
0: Enable (Default)
1: Disable
“0”ͷ࣌ɺALC1Ϧϛολಈ࡞ʹΑΓIPGA஋͕มߋ͞ΕΔͷ͸ɺθϩΫϩε͢Δ͔·ͨ͸λΠϜΞ
΢τͨ࣌͠Ͱ͢ɻθϩΫϩελΠϜΞ΢τ࣌ؒ͸ɺALC1ϦΧόϦಈ࡞࣌ͷθϩΫϩελΠϜΞ΢
τ࣌ؒͱಉ͡Ͱ͢ɻ“1”ͷ࣌ɺALC1Ϧϛολಈ࡞ʹΑΓIPGA஋͸ॠ࣌ʹมߋ͞Ε·͢ɻ


MS0317-J-01
- 51 -
2004/11