AK4673 Datasheet, PDF (66/107 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP-AMP and Touch Screen Controller

HP-AMP
AK4673
CR
0.22μ
10Ω
Headphone
16Ω
[AK4673]
Figure 56. External Circuit Example of Headphone
HPG bit R [Ω] C [μF]
0
220
100
0
6.8
100
47
16
100
47
0
220
1
100
100
22
10
Note 40. Output power at 16Ω load.
Note 41. Output signal is clipped.
fc [Hz]
BOOST
=OFF
45
100
70
149
50
106
45
100
62
137
fc [Hz]
BOOST
=MIN
@fs=44.1kHz
17
43
28
78
19
47
17
43
25
69
Output Power [mW]@0dBFS
HVDD=3.0V HVDD=3.3V HVDD=5V
AVDD=3.0V AVDD=3.3V AVDD=3.3V
25.3
30.6
30.6
12.5
15.1
15.1
6.3
7.7
7.7
51
(Note 41)
62
(Note 41)
70
1.1
1.3
1.3
Table 55. External Circuit Example
<Headphone-Amp PSRR>
When HVDD is directly supplied from the battery in the mobile phone system, RF noise may influences headphone
output performance. When VBAT bit is set to “1”, HP-Amp PSRR for the noise applied to HVDD is improved. In this
case, HP-Amp common voltage is 0.64 x AVDD (typ). When AVDD is 3.3V, common voltage is 2.1V. Therefore, when
HVDD voltage becomes lower than 4.2V, the output signal will be clipped easily.
VBAT bit
0
Common Voltage [V]
0.5 x HVDD
Table 56. HP-Amp Common Voltage
1
0.64 x AVDD
<Wired OR with External Headphone-Amp>
When PMVCM=PMHPL=PMHPR bits = “0” and HPZ bit = “1”, HP-Amp is powered-down and HPL/R pins are
pulled-down to VSS2 by 200kΩ (typ). In this setting, it is available to connect HP-Amp of AK4673 and external single
supply HP-Amp by “wired OR”. In this mode, power supply current is 20μA(typ).
PMVCM
x
0
1
1
PMHPL/R
0
0
1
1
HPMTN
HPZ
Mode
x
0
Power-down & Mute
x
1
Power-down
0
x
Mute
1
x
Normal Operation
Table 57. HP-Amp Mode Setting (x: Don’t care)
HPL/R pins
VSS2
Pull-down by 200kΩ
VSS2
Normal Operation
(default)
MS0670-E-00
- 66 -
2007/09