ak4564 AKM Semiconductor, Inc., ak4564 Datasheet - Page 21

• Manufacturer Part Number: ak4564
• Description: 16bit Codec With Built-in Alc And Mic/hp/spk-amp
• Manufacturer: AKM Semiconductor, Inc.

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)
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)
MS0140-E-01
* FS = Full Scale
Figure 15. Headphone-Amp Level Diagram (AVDD=2.8V, HVDD=4.5V, HPG = “1”, OATT = 0dB& -10.5dB)
FS-12dB
FS
OATT=-10.5dB
Load Resistance (min)
Table 3. Load resistance and output voltage of Headphone-Amp
Output Voltage
HPG bit
HVDD
-16.5dBV
-4.5dBV
OATT = 0dB
OATT+DAC
(0.59 x AVDD) Vpp
2.6 3.6V
- 21 -
22
-16.5dBV
0
-15dBV
-4.5dBV
-27dBV
HP-AMP (+16.5dB)
(0.98 x AVDD) Vpp
4.0 5.5V
-10.5dBV
+12dBV
+1.5dBV
100
0dBV
1
+10dBV
-10dBV
-20dBV
-30dBV
0dBV
2002/07