AK4648 Datasheet, PDF (69/119 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP/SPK-AMP

[AK4648]
■ Headphone-Amp
Power supply voltage for the Headphone-Amp is supplied from the HVDD pin and centered on the HVDD/2 voltage at
VBAT bit = “0”. The load resistance is 16Ω (min.). HPG3-0 bits select the output voltage (Table 58).
When HPM bit = “1”, DAC output signal is output to HPL and HPR pins as (L+R)/2 mono signal.
When HPM3 bit = “1”, the signal selected by MICL3 and MICR3 bits (LIN3/RIN3 inputs or MIC-Amp outputs) to HPL
and HPR pins as (L+R)/2 mono signal.
HPG3-0 bits Volume [dB]
FH-DH
N/A
CH
+3dB
BH
0dB
(default)
AH
-3dB
9H
-6dB
8H
-9dB
7H
-12dB
6H
-15dB
5H
-18dB
4H
-21dB
3H
-24dB
2H
-27dB
1H
-30dB
0H
-33dB
Table 58. Headphone-Amp volume setting (N/A: Not available)
<Connection with Headphone>
The AK4648 can be connected with the headphone as follows.
1. Single-ended Mode (In case of not using common buffer for Headphone-Amp)
HP-Amp
VCOM Amp for
HP-Amp
HPL pin
C
R
0.22μF
10Ω
HVCM pin
Headphone
16Ω
HP-Amp
16Ω
HPR pin
C
R
0.22μF
10Ω
Figure 51. External circuit example of HP-Amp (Single-ended Mode)
MS0625-E-01
- 69 -
2007/06