[AK4709]
■ Volume Control #1 (Main Volume)
The AK4709 has main volume control (Volume #1) as shown in Table 8.
(02H: D5-D0)
L5
1
1
1
0
L4
0
0
0
1
L3
0
0
0
1
L2
0
0
0
1
L1
1
0
0
1
L0
0
1
0
1
Gain
+6dB
+4dB
+2dB
0dB
(default)
…
0
0
…
0
0
…
0
0
…
0
0
…
0
0
…
1
0
…
-60dB
Mute
Note: The output must not exceed 2.15Vrms.
Table 8. Volume #1
When the MOD bit = “1”(default), changing volume levels does not cause pop noise. MDT1-0 bits select the transition
time (Table 9). 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 built-in volume controller
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 compared. When
the MOD bit = “0” then there is no transition time and the gain changes immediately. This change may cause a click noise.
WR
WR
WR
[Gain=1EH]
[Gain=1DH]
[Gain=1CH]
1DH
1CH
1FH
1EH
Gain Register
Actual Gain
compare
compare compare
(to 1DH) (to 1CH)
1CH
(to 1EH)
1EH
1FH
1DH
Transition Time (5.3ms to 42.7ms pop free.)
Figure 6. Volume Change Operation (MOD bit = “1”)
MDT1
MDT0
Transition Time
5.3ms
0
0
1
1
0
1
0
1
10.7ms
21.3ms
42.7ms
(default)
Table 9. Volume Transition Time (typ.)
MS1319-E-00
2011/07
- 19 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
