AK4648 Datasheet, PDF (14/119 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP/SPK-AMP

[AK4648]
Parameter
min
typ
max
Units
Headphone-Amp Characteristics in Pseudo Cap-less mode:
DAC → HPL/HPR pins, ALC=OFF, IVOL=0dB, DVOL=0dB; VBAT bit = “0”; PMHPC bit = “1”; unless otherwise
specified.
Headphone Volume (HPG3-0 bits)
Volume Range
-33
-
+3
dB
Gain Step: +3dB to –33dB
1.5
3
4.5
dB
Output Voltage (Note 22)
HPG = 0dB, 0dBFS, HVDD=3.6V, R_L=22.8Ω
1.58
HPG = +3dB, 0dBFS, HVDD=4.5V, R_L=100Ω
2.24
HPG = +3dB, -2dBFS, HVDD=3.6V, R_L=16Ω (Po=40mW)
-
HPG = +3dB, 0dBFS, HVDD=4.5V, R_L=16Ω (Po=62.5mW)
-
S/(N+D)
1.98
2.38
Vpp
2.8
3.36
Vpp
0.8
-
Vrms
1.0
-
Vrms
HPG = 0dB, −3dBFS, HVDD=3.6V, R_L=22.8Ω
30
50
-
dBFS
HPG = +3dB, −3dBFS, HVDD=4.5V, R_L=100Ω
-
60
-
dBFS
HPG = +3dB, -2dBFS, HVDD=3.6V, R_L=16Ω (Po=40mW)
-
45
-
dBFS
HPG = +3dB, 0dBFS, HVDD=4.5V, R_L=16Ω (Po=62.5mW)
-
40
-
dBFS
S/N (A-weighted)
(Note 23)
(Note 24)
80
90
-
dB
-
90
-
dB
Interchannel Isolation
(Note 23)
(Note 24)
40
50
-
dB
-
60
-
dB
Interchannel Gain Mismatch
(Note 23)
(Note 24)
-
0.1
0.8
dB
-
0.1
0.8
dB
Load Resistance (Note 25)
16
-
-
Ω
Load Capacitance
C1 in Figure 3
-
C2 in Figure 3
-
-
30
pF
-
300
pF
Note 22. Output voltage is proportional to AVDD voltage.
Vout = 0.6 x AVDD(typ.) @ HPG = 0dB, 0.848 x AVDD(typ.) @ HPG = +3dB
Note 23. HPG = 0dB, HVDD=3.6V, R_L=22.8Ω
Note 24. HPG = +3dB, HVDD=4.5V, R_L=100Ω
Note 25. Load resistance is inserted between HPL pin (HPR pin) and HVCM pin.
HP-Amp
HPL/HPR pin
Measurement Point
VCOM Amp for
HP-Amp
6.8Ω
C1 0.22μF
10Ω
HVCM pin
C2
16Ω
C2
Note: Impedance between headphone and HVCM pin should be as lower as possible. If the impedance is
larger, crosstalk and distortion might be degraded.
Figure 3. Example external output circuit of HP-Amp in Pseudo Cap-less Mode
MS0625-E-01
- 14 -
2007/06