AK4647VN AKM [Asahi Kasei Microsystems], AK4647VN Datasheet - Page 45

• Manufacturer Part Number: AK4647VN
• Description: Stereo CODEC with MIC/HP-AMP
• Manufacturer: AKM [Asahi Kasei Microsystems]

ASAHI KASEI
<External Circuit of Headphone-Amp >
When BOOST=OFF, the cut-off frequency (fc) of Headphone-Amp depends on the external resistor and capacitor. This
fc can be shifted to lower frequency by using bass boost function. Table 40 shows the cut off frequency and the output
power for various resistor/capacitor combinations. The headphone impedance R
HVDD = 3.0, 3.3 and 5.0V. The output voltage of headphone is 0.6 x AVDD (Vpp) @HPG bit = “0” and 0.91 x AVDD
(Vpp) @HPG bit = “1”.
When an external resistor R is smaller than 12Ω, put an oscillation prevention circuit (0.22μF±20% capacitor and
10Ω±20% resistor) because it has the possibility that Headphone-Amp oscillates.
MS0566-E-00
HPG bit
0
1
R [Ω]
100
6.8
16
0
C [μF]
100
100
220
100
47
47
22
10
Figure 34. External Circuit Example of Headphone
HP-AMP
AK4647
BOOST=OFF
Table 40. External Circuit Example
fc [Hz]
149
106
100
137
70
50
45
62
10Ω
0.22μ
R
- 45 -
BOOST=MIN
@fs=44.1kHz
fc [Hz]
C
28
78
19
47
17
43
25
69
Headphone
16Ω
2.7V
10.1
L
5.1
0.9
33
Output Power [mW]@0dBFS
is 16Ω. Output powers are shown at
3.0V
12.5
6.3
1.1
41
3.3V
15.1
7.7
1.3
[AK4647]
50
2006/11