|
AK4645AEZ Datasheet, PDF (35/85 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP-AMP | |||
|
◁ |
[AK4645A]
3) EQ
fs: αϯÏϦϯάप೾਺
fc1: Ûͷप೾਺
fc2: ྵ఺ͷप೾਺
f: à³à¾à§´ß¸à¤ªà³¾à¨º
K: ήΠϯ[dB] (à ·à+12dBÎÍ°àªà°Í°ÍÎ͢ɻ)
Ϩδελàªà°
EQA[15:0] bits =A, EQB[13:0] bits =B, EQC[15:0] bits =C
(MSB=EQA15, EQB13, EQC15; LSB=EQA0, EQB0, EQC0)
1 + 1 / tan (Ïfc2/fs)
A = 10K/20 x
,
1 + 1 / tan (Ïfc1/fs)
1 â 1 / tan (Ïfc1/fs)
B=
,
1 + 1 / tan (Ïfc1/fs)
1 â 1 / tan (Ïfc2/fs)
C =10K/20 x
1 + 1 / tan (Ïfc1/fs)
à°»à¡Ø਺
ৼ෯
Ò૬
H(z) =
A + Cz â1
1 + Bz â1
M(f) =
A2 + C2 + 2ACcos (2Ïf/fs)
1 + B2 + 2Bcos (2Ïf/fs)
θ(f) = tan â1
(ABâC)sin (2Ïf/fs)
A + BC + (AB+C)cos (2Ïf/fs)
[à§à£Í´ÎÎà¢à¥ÍÎͨÏÎϧλÜ਺Î࣮਺ÍÎ2à¨à¨º(2ͷิ਺)Îม͢׵Îà¤à¥±]
X=(à§à£Í´ÎÎà¢à¥ÍÎ࣮ͨ਺ͷÏÎϧλÜ਺) x 213
ÍÍ·XÍ·à¦à¨ºà°ºÒÔ¼Îà¢à£ºÞà³Í ͨà©à¨ºà®Î2à¨à¨º(2ͷิ਺)Í´à¸¡Í¯Í ×µÔ¼ÍÍÉ»
Ö¤ÏÎϧλÜ਺àªà°Ï¨Î´ÎµÎ»Í·MSB͸à·ß¸ÏοÏͰ͢ɻ
[ÏÎϧλÜ਺ͷàªà°à¾«]
1) FIL1ÏϩοΫ
ྫ: fs=44.1kHz, fc=100HzÍ·HPFÍ·à§ß¹
F1AS bit = â0â
F1A[13:0] bits = 01 1111 1100 0110
F1B[13:0] bits = 10 0000 0111 0100
2) EQÏϩοΫ
ྫ: fs=44.1kHz, fc1=300Hz, fc2=3000Hz, Gain=+8dBÍ·à§ß¹
Gain[dB]
+8dB
fc1
fc2
EQA[15:0] bits = 0000 1001 0110 1110
EQB[13:0] bits = 10 0001 0101 1001
EQC[15:0] bits = 1111 1001 1110 1111
Frequency
MS0986-J-00
- 35 -
2008/07
|
▷ |