alc250-lf Realtek Semiconductor Corporation, alc250-lf Datasheet - Page 43

• Manufacturer Part Number: alc250-lf
• Description: Two-channel Ac?97 2.3 Audio Codec With Equalizer
• Manufacturer: Realtek Semiconductor Corporation

9.9 POWER OFF CD Function
The ‘POWER OFF CD’ function describes a state which, after the system has been shut down and a +5V analog power is
supplied at VAUX(pin-34), the ALC250 will turn on the CD-IN op and output amplifier. It is possible to design a system which
will save op-amp circuitry and bypass CD output directly to the speaker.
The figure below indicates the system application circuitry to support the ‘POWER OFF CD’ function. The operation mode is
defined by +3.3VCC and +5Vaux.
Two-Channel AC’97 2.3 Audio Codec
1
2
3
4
+3.3VCC
0
0
0
Yes (1)
Yes (1)
No (0)
No (0)
1u
1u
1u
11
10
12
13
14
15
16
17
18
20
21
22
23
24
2
3
6
5
8
XTL-IN
XTL-OUT
RESET#
BITCLK
SYNC
SDOUT
SDIN
PC-BEEP
PHONE
AUX-L
AUX-R
JD2
JD1
CD-L
CD-R
MIC1
MIC2
LINE-L
LINE-R
0.1u
POWER OFF CD Circuitry
+5Vaux
Yes (1)
Yes (1)
No (0)
No (0)
+
10u
ALC250
38
+3.3VDD
Normal (+5Vaudio must be on)
Normal (+5Vaudio must be on)
MONO-OUT/VREFOUT3
1N5817M/CYL
Operation Mode
Power Off CD
SPDIFI/EAPD
Shut Down
+
VREFOUT2
LINEOUT-R
LINEOUT-L
10u
VREFOUT
HPOUT-R
HPOUT-L
DCVOL
D1
SPDIFO
XTLSEL
AFILT1
AFILT2
GPIO0
GPIO1
+5VA
VREF
VAUX
NC
NC
NC
0.1u
35
36
37
27
28
29
30
31
32
33
34
43
44
45
46
47
48
39
40
41
U3
1N5817M/CYL
D2
ALC250 DataSheet
+5Vstandby
Rev1.3