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AK5366 Datasheet, PDF (23/43 Pages) Asahi Kasei Microsystems – 24 BIT 48KHZ ADC WITH SELECTOR/PGA /ALC | |||
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ASAHI KASEI
[AK5366]
 Input Volume
The AK5366 includes two independent channel analog volumes (IPGA) with 37 levels at 0.5dB steps located in front of
the ADC.
The IPGA is a true analog volume control that improves the S/N ratio as seen in Table 9. Independent zero-crossing
detection is used to ensure level changes only occur during zero-crossings. If there are no zero-crossings, the level will
then change after a time-out period (Table 10); the time-out period scales with fs. If a new value is written to the IPGA
register before the IPGA changes at the zero crossing or time-out, the previous value becomes invalid. The timer (channel
independent) for time-out is reset and the timer restarts for new IPGA value.
Input Gain Setting
0dB
+6dB
fs=48kHz, A-weight
103dB
100dB
Table 9. PGA+ADC S/N
+18dB
89dB
ZTM1
0
0
1
1
ZTM0
0
1
0
1
Zero crossing timeout period @fs=48kHz
288/fs
6ms
1152/fs
24ms
2304/fs
48ms
4608/fs
96ms
Table 10. Zero crossing timeout period
Default
[Writing operation at ALC Enable]
Writing to the area over 7FH (Table 17) of IPGL/R registers (04H, 05H) is ignored during ALC operation. After ALC
is disabled, the IPGA changes to the last written data by zero-crossing or time-out. In case of writing to the DATT area
(08H, 09H), the DATT changes even if ALC is enabled.
 Output Volume
The AK5366 includes two independent channel digital volumes (DATT) with 144 levels at 0.5dB steps located behind
the ADC. When changing levels, transitions are executed via soft changes; thus no switching noise occurs during these
transitions. The data must not be written over 90H.
ATTL/R7-0 Attenuation
8FH
+8.0dB
8EH
+7.5dB
:
:
81H
+1.0dB
80H
+0.5dB
7FH
0dB
Default
7EH
â0.5dB
7DH
â1.0dB
:
:
02H
â62.5dB
01H
â63dB
00H
Mute (ââ)
Table 11. DATT Code Table
MS0309-E-00
- 23 -
2004/05
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