stac9723t ETC-unknow, stac9723t Datasheet - Page 45

• Manufacturer Part Number: stac9723t
• Description: Stereo Ac 97 Codec With Multi-codec Option
• Manufacturer: ETC-unknow

SigmaTel, Inc.
In PC applications, one power supply input to the STAC9721/23 may be derived from a supply regulator
(as shown in Figure 3) and the other directly from the PCI power supply bus. When power is applied to
the PC, the regulated supply input to the IC will be applied some time delay after the PCI power supply.
Without proper on-chip partitioning of the analog and digital circuitry, some manufacturer's codecs would
be subject to on-chip SCR type latch-up.
SigmaTel’s STAC9721/23 specifically allows power-up sequencing delays between the analog (AVddx)
and digital (VDddx) supply pins. These two power supplies can power-up independently and at different
rates with no adverse effects to the codec. The IC is designed with independent analog and digital
circuitry that prevents on-chip SCR type latch-up.
.
04/07/00
0.1uF
3.3V or 5V ± 5%
NOTE: Pins 31, 33, 34, 40
43, 44, and 48 are No Connects
820pF
820pF
1uF
32
12
13
14
15
16
17
18
19
20
21
22
23
24
29
30
0.1uF
SPLIT INDEPENDENT POWER SUPPLY OPERATION
PC
PHONE
AUX_L
AUX_R
VIDEO_L
VIDEO_R
CD_L
CD_GND
CD_R
MIC1
MIC2
LINE_IN_L
LINE_IN_R
CAP2
AFILT1
AFILT2
_
BEEP
1uF
25
AVdd1
26
AVss1
AVdd2
STAC9721/23
AVss2
38
SigmaTel
42
Data Sheet
DVss1
Appendix A
4
0.1uF
0.1uF
DVss2
45
7
LNLVL_OUT_L
39
1
DVdd1
DVdd2
LNLVL_OUT_R
10uF
LINE_OUT_R
SDATA_OUT
LINE_OUT_L
MONO_OUT
41
9
SDATA_IN
XTL_OUT
BIT_CLK
Analog Gnd
XTL_IN
RESET
Vrefout
SYNC
APOP
EAPD
CAP1
CAP3
CID0
CID1
Vref
0.1uF
plane as close to power
** Teminate ground
supply as possible
28
33
31
45
46
2
3
5
6
8
10
11
27
34
35
36
37
47
3.3V or 5V ± 5%
0.1uF
24.576MHz
27pF
100uF
Digital Gnd
Optional Anti-Pop Circuit
27pF
EMI
Filter
22 ohms
STAC9721
10uF
1uF
27pF
04/07/00