ASAHI KASEI
[AK4538]
Parameter
min
typ
max
Headphone-Amp Characteristics:
R
L
=22.8Ω, DAC
→
HPL/HPR, DATT=0dB
1.54
1.92
2.30
Output Voltage (Note 10)
60
70
S/(N+D)
(−3dBFS)
S/N
(A-weighted)
80
90
70
85
Interchannel Isolation
0.1
0.5
Interchannel Gain Mismatch
20
Load Resistance
Load Capacitance
(C1 of Figure 2)
30
300
(C2 of Figure 2)
Speaker-Amp Characteristics:
R
L
=8Ω, BTL, DAC
→
MOUT2
→
MIN
→
SPP/SPN, ALC2=OFF
Output Voltage
(Note 11)
2.37
2.96
3.55
S/(N+D)
50
64
82
90
S/N
(A-weighted)
Load Resistance
8
30
Load Capacitance
AUX Input:
AUXIN+, AUXIN- pin
1.98
Maximum Input Voltage (Note 12)
25
40
55
Input Resistance
Step Size
1
3
5
Gain Control Range
+24
−21
BEEP Input:
BEEPL, BEEPR, BEEPM pin
1.98
Maximum Input Voltage (Note 13)
14
20
26
Feedback Resistance
Mono Input:
MIN pin
1.98
Maximum Input Voltage (Note 14)
12
24
36
Input Resistance
(Note 15)
Mono Output:
R
L
=10kΩ, DAC
→
MIX
→
MOUT2
1.94
Output Voltage
(Note 16)
Load Resistance
10
30
Load Capacitance (Note 17)
Units
Vpp
dBFS
dB
dB
dB
Ω
pF
pF
Vpp
dB
dB
Ω
pF
Vpp
kΩ
dB
dB
Vpp
kΩ
Vpp
kΩ
Vpp
kΩ
pF
Note 10. Output voltage is proportional to AVDD voltage. Vout = 0.582 x AVDD.
Note 11. Output voltage is proportional to HVDD voltage. Vout = 0.897 x AVDD at Full-differential output.
Note 12. Maximum Input Voltage is proportional to AVDD voltage. Vin = 0.6 x AVDD.
Note 13. Maximum Input Voltage is proportional to AVDD voltage. Vin = 0.6 x AVDD.BEEP-AMP can’t output more
than this maximum voltage.
Note 14. Maximum Input Voltage is proportional to AVDD voltage. Vin = 0.6 x AVDD.
Note 15. When ALC2 Gain is changed, this typical value changes between 22kΩ and 26kΩ.
Note 16. Output Voltage is proportional to AVDD voltage. Vout = 0.588 x AVDD.
Note 17. When the output pin drives a capacitive load, a resistor should be added in series between the output pin and
capacitive load.
HP-Amp
HPL/HPR pin
47µF
> 6.8Ω
C1
C2
16Ω
Figure 2. Headphone-amp output circuit
MS0198-E-01
-8-
2003/5
AKM [ ASAHI KASEI MICROSYSTEMS ]
