AK4705 Datasheet, PDF (25/50 Pages) Asahi Kasei Microsystems – 2ch 24bit DAC with AV SCART Switch

[AK4705]
■ Volume Control #1 (Main Volume)
The AK4705 has main volume control (Volume #1) as shown in Table 11.
(02H: D5-D0)
L5
L4
L3
L2
L1
L0
1
0
0
0
1
0
1
0
0
0
0
1
1
0
0
0
0
0
0
1
1
1
1
1
…
…
…
…
…
…
0
0
0
0
0
1
0
0
0
0
0
0
Note: The output must not exceed 3Vrms.
Table 11. Volume #1
Gain
+6dB
+4dB
+2dB
0dB
…
-60dB
Mute
(default)
When the MOD bit = “1”(default), changing levels don’t have pop noise. MDT1-0 bits select the transition time (Table
12). When the new gain value 1EH(-2dB) is written to gain resistor while the actual (stable) gain is 1FH(0dB), the gain
changes to 1EH(-2dB) within the transition time selected by MDT1-0 bits. The AK4705 compares the actual gain to the
value of gain register after finishing the transition time, and re-changes the actual gain to new resister value within the
transition time if the register value is different from the actual gain. When the MOD bit = “0”, there is no transition time
and the gain changes immediately. This change may cause a click noise.
WR
[Gain=1EH]
WR
[Gain=1DH]
WR
[Gain=1CH]
Gain Register
Actual Gain
1FH
1EH
compare
1FH (to 1EH)
1EH
1DH
1CH
compare compare
(to 1DH) (to 1CH)
1CH
1DH
Transition Time (256/fs to 2048/fs. pop free.)
Figure 7. Volume Change Operation (MOD bit = “1”)
MDT1
0
0
1
1
MDT0
Transition Time
0
256/fs
1
512/fs
0
1024/fs
1
2048/fs
Table 12. Volume Transition Time
(default)
MS0451-E-01
- 25 -
2007/06