AK4564 Datasheet, PDF (21/48 Pages) Asahi Kasei Microsystems – 16BIT CODEC WITH BUILT-IN ALC AND MIC/HP/SPK-AMP

ASAHI KASEI
[AK4564]
n Headphone-Amps
The Power supply voltage for Headphone-Amp is supplied from HVDD pin and centered around HVCM voltage. The
load resistance and output voltage are specified by HVDD voltage. The output voltage can be changed by supplying
AVDD voltage and HPG bit. (Refer to Table 3)
HVDD
2.6 ∼ 3.6V
4.0 ∼ 5.5V
HPG bit
0
1
Output Voltage
(0.59 x AVDD) Vpp (0.98 x AVDD) Vpp
Load Resistance (min)
22Ω
100Ω
Table 3. Load resistance and output voltage of Headphone-Amp
When HPG bit is “0”, the signals from MIX1, DAC and BEEP2 are output from Headphone-Amps with 0dB gain. When
HPG is “1”, the signals from MIX1, DAC and BEEP2 output from Headphone-Amps with +16.5dB gain. (Refer to Figure
15)
When HPDAC, HPMIX and BEEP2H bits are “0”, the input signals to Headphone-Amp are disabled and HPL/HPR pins
output HVCM voltage.
HPMIX, HPDAC and BEEP2H bits control ON/OFF of each input signal. When these bits are “1” at the same time, all
input signals are mixed by the ration of “1:1”. (Refer to Figure 13 and Figure 16)
OATT = 0dB
-4.5dBV
FS
-4.5dBV
FS-12dB
-16.5dBV
OATT=-10.5dB
-15dBV
-16.5dBV
-27dBV
+12dBV
+10dBV
+1.5dBV
0dBV
0dBV
-10.5dBV _-10dBV
-20dBV
-30dBV
OATT+DAC
HP-AMP (+16.5dB)
Figure 15. Headphone-Amp Level Diagram (AVDD=2.8V, HVDD=4.5V, HPG = “1”, OATT = 0dB& -10.5dB)
* FS = Full Scale
MS0140-E-01
- 21 -
2002/07