AK5701 Datasheet, PDF (39/62 Pages) Asahi Kasei Microsystems – PLL & MIC-AMP 16-Bit Stereo ADC

ASAHI KASEI
[AK5701]
IVL7-0, IVR7-0 bitͷॻ͖ࠐΈΛଓ͚ͯߦ͏৔߹͸ɺθϩΫϩελΠϜΞ΢τ࣌ؒҎ্ͷִؒΛ͚͋ͯߦͬͯ
Լ͍͞ɻॴఆͷִؒΛ͚͋ͳ͍Ͱॻ͖ࠐΈΛߦ͏ͱɺθϩΫϩεΧ΢ϯλ͕ຖճϦηοτ͞ΕϘϦϡʔϜ͕
੾ΓସΘΓ·ͤΜɻͨͩ͠ɺॻ͖ࠐΉϨδελ஋͕લճͱಉ͡஋ͷ৔߹͸ॻ͖ࠐΈ͕ແࢹ͞ΕɺθϩΫϩε
Χ΢ϯλ͸Ϧηοτ͞Εͳ͍ͷͰɺθϩΫϩελΠϜΞ΢τ࣌ؒΑΓ୹ִ͍ؒͰॻ͖ࠐΈΛߦ͏͜ͱ͕Ͱ͖
·͢ɻ
ALC bit
ALC Status
Disable
Enable
Disable
IVL7-0 bits
E1H(+30dB)
IVR7-0 bits
C6H(+20dB)
Internal IVL
Internal IVR
E1H(+30dB)
C6H(+20dB)
E1(+30dB) --> F1(+36dB)
(1)
E1(+30dB) --> F1(+36dB)
E1(+30dB)
(2)
C6H(+20dB)
Figure 40. ALCಈ࡞தͷIVOLಈ࡞ྫ
(1) ALC։࢝࣌ʹIVLͱIVRͷ஋͕ҟͳ͍ͬͯΔ৔߹͸ɺIVLͷ஋͕ελʔτ஋ʹͳΓ·͢ɻALC bit = “1”Λ
ॻ͖ࠐΜͰ͔ΒIVL7-0 bitsͷ஋ͰALCಈ࡞Λ։࢝͢Δ·Ͱͷ଴ͪ࣌ؒ͸࠷େͰϦΧόϦ଴ؒ࣌ػ
(WTM1-0 bits) + θϩΫϩελΠϜΞ΢τ࣌ؒ(ZTM1-0 bits)Ͱ͢ɻ
(2) ALCಈ࡞த͸ɺIVL, IVRͷϨδελ(18H, 19H)ʹॻ͖ࠐΈΛߦͬͯ΋൓ө͞Ε·ͤΜɻALC͕Disable͞Ε
ޙͨɺθϩΫϩε·ͨ͸θϩΫϩελΠϜΞ΢τ࣌ʹͦͷ஋͕൓ө͞Ε·͢ɻ࠶౓ALCΛEnable͢Δ৔
߹͸ɺALC bit = “0”ͷޙɺθϩΫϩελΠϜΞ΢τ࣌ؒҎ্ͷִؒΛۭ͚ͯALC bit = “1”Λઃఆͯ͠Լ͞
͍ɻ
„ γεςϜϦηοτ
ʹ্ཱ࣌͛ͪݯి͸ɺPDN pinʹҰ౓ “L”Λೖྗͯ͠ϦηοτΛߦͬͯԼ͍͞ɻγεςϜϦηοτ͕ߦΘΕΔ
ͱɺAK5701ͷ಺෦Ϩδελ͸શͯॳظ஋ʹͳΓ·͢ɻ
PMADL=PMADR bits = “0”ͷঢ়ଶ͔ΒPMADL bit·ͨ͸PMADR bitΛ “0” → “1”ʹมߋ͢Δ͜ͱͰɺADCͷॳ
ظԽαΠΫϧ͕։࢝͞Ε·͢ɻॳظԽαΠΫϧ͸HPF1-0 bits = “00”ͷͱ͖3088/fs=70.0ms@fs=44.1kHzͰ͢
(Table 30)ɻॳظԽαΠΫϧதͷADCग़ྗσʔλ͸2’sίϯϓϦϝϯτͷ “0”Ͱ͢ɻॳظԽαΠΫϧऴྃޙɺ
ADCͷग़ྗ͸Ξφϩάೖྗ৴߸ʹ૬౰͢ΔσʔλʹητϦϯά͠·͢ɻ
HPF1 bit
0
0
1
1
HPF0 bit
0
1
0
1
Cycle
3088/fs
1552/fs
Init Cycle
fs=44.1kHz
fs=22.05kHz
70.0ms
(ਪ঑஋)
140.0ms
35.2ms
70.4ms
(ਪ঑஋)
784/fs
17.8ms
35.6ms
N/A
N/A
N/A
Table 30. ADCظॳԽαΠΫϧઃఆ
fs=11.025kHz
280.1ms
Default
140.8ms
71.1ms
(ਪ঑஋)
N/A
MS0404-J-00
- 39 -
2005/08