Datasheet
DV
DD1
XTL_OUT
SDATA_OUT
48
1
47 46
2
3
4
5
XTL_IN
DV
SS1
CIN
EAPD
ID1#
45
ID0#
6
7
8
9
10
11
12
LM4550
$&µ97 Rev 2.1
Codec
36
35
34
33
32
31
30
29
28
27
26
25
BIT_CLK
SDATA_IN
SYNC
RESET#
PC_BEEP
DV
DD2
DV
SS2
LINE_OUT_R
3DP
NC
LINE_OUT_L
3DN
NC
NC
AV
SS
NC
V
REF
V
REF_OUT
AV
DD
44
NC
43
NC
42
NC
41
HP_OUT_R
40
HP_OUT_C
39
HP_OUT_L
38
NC
37
MONO_OUT
PHONE
AUX_L
AUX_R
VIDEO_L
VIDEO_R
CD_L
CD_GND
CD_R
MIC1
MIC2
LINE_IN_L
LINE_IN_R
13 14 15 16 17 18 19 20 21 22 23 24
OBSOLETE
LM4550
SNAS032F –SEPTEMBER 2001–REVISED APRIL 2013
www.ti.com
Connection Diagram
Figure 10. 48 Pin LQFP - Top View
See Package Number PT
Pin Descriptions
Table 1. ANALOG I/O
Name Pin I / O Functional Description
Mono Input
This line level (1 Vrms nominal) mono input is mixed equally into both channels of the Stereo Mix
signal at MIX2 under the control of the PC_Beep Volume control register, 0Ah. The PC_BEEP level
can be muted or adjusted from 0 dB to -45 dB in 3 dB steps. The Stereo Mix signal feeds both the
PC_BEEP 12 I
Line Out and Headphone Out analog outputs and is also selectable at the Record Select Mux. During
Initialization or Cold Reset, (reset pin held active low), PC_BEEP is switched directly to both channels
of the Line Out stereo output, bypassing all volume controls. This allows signals such as PC power-on
self-test tones to be heard through the PC's audio system before the codec registers are configured.
Mono Input
This line level (1 Vrms nominal) mono input is selectable at the Record Select Mux for conversion by
either or both channels of the stereo ADC. It can also be mixed equally into both channels of the
PHONE 13 I
Stereo Mix signal at MIX2 under the control of the Phone Volume register, 0Ch. The PHONE level can
be muted or adjusted from +12 dB to -34.5 dB in 1.5 dB steps. The Stereo Mix signal feeds both the
Line Out and Headphone Out analog stereo outputs and is also selectable at the Record Select Mux.
Left Stereo Channel Input
This line level input (1 Vrms nominal) is selectable at the left channel of the stereo Record Select Mux
for conversion by the left channel ADC. It can also be mixed into the left channel of the Stereo Mix 3D
AUX_L 14 I
signal at MIX1 under the control of the Aux Volume register, 16h. The AUX_L level can be muted
(along with AUX_R) or adjusted from +12 dB to -34.5 dB in 1.5 dB steps. Stereo Mix 3D is combined
into the Stereo Mix signal at MIX2 for access to the stereo outputs Line Out and Headphone Out.
Right Stereo Channel Input
This line level input (1 Vrms nominal) is selectable at the right channel of the stereo Record Select
Mux for conversion by the right channel ADC. It can also be mixed into the right channel of the Stereo
AUX_R 15 I Mix 3D signal at MIX1 under the control of the Aux Volume register, 16h. The AUX_R level can be
muted (along with AUX_L) or adjusted from +12 dB to -34.5 dB in 1.5 dB steps. Stereo Mix 3D is
combined into the Stereo Mix signal at MIX2 for access to the stereo outputs Line Out and Headphone
Out.
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