ak4642e AKM Semiconductor, Inc., ak4642e Datasheet - Page 48

• Manufacturer Part Number: ak4642e
• Description: Stereo Codec With Mic/hp/spk-amp
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
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 39 shows the cut off frequency and the output
power for various resistor/capacitor combinations. The headphone impedance R
HVDD = 2.7, 3.0 and 3.3V. The output voltage of headphone is 0.6 x AVDD (Vpp).
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.
MS0420-E-00
HPG bit
0
1
R [Ω]
100
6.8
16
0
C [µF]
100
100
220
100
47
47
22
10
Figure 32. External Circuit Example of Headphone
HP-AMP
AK4642
BOOST=OFF
Table 39. External Circuit Example
fc [Hz]
149
106
100
137
70
50
45
62
10Ω
0.22µ
R
- 48 -
BOOST=MIN
@fs=44.1kHz
fc [Hz]
C
28
78
19
47
17
43
25
69
Headphone
16Ω
L
2.7V
10.1
5.1
0.9
is 16Ω. Output powers are shown at
33
Output Power [mW]@0dBFS
3.0V
12.5
6.3
1.1
41
[AK4642EN]
3.3V
15.1
7.7
1.3
50
2005/09