LM4548A National Semiconductor, LM4548A Datasheet - Page 10
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LM4548A
Manufacturer Part Number
LM4548A
Description
2 Multi-Channel Audio Codec
Manufacturer
National Semiconductor
Datasheet
1.LM4548A.pdf
(28 pages)
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Manufacturer
Quantity
Price
Part Number:
LM4548AVH
Manufacturer:
NS/国半
Quantity:
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Pin Descriptions
VIDEO_R
VIDEO_L
CD_GND
AUX_R
AUX_L
Name
CD_R
CD_L
Pin
14
15
16
17
18
19
20
I / O
I
I
I
I
I
I
I
(Continued)
Functional Description
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 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 Line Level 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 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 Line Level Out.
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 signal at MIX1 under the control of the Video Volume register, 14h. The
VIDEO_L level can be muted (along with VIDEO_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 Line Level 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 Mix 3D signal at MIX1 under the control of the Video Volume register,
14h. The VIDEO_R level can be muted (along with VIDEO_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 Line Level Out.
Left Stereo Channel Input
This line level input (1 Vrms nominal) is selectable at the left channel of the stereo Input Mux
for conversion by the left channel ADC. It can also be mixed into the left channel of the
Stereo Mix 3D signal at MIX1 under the control of the CD Volume register, 12h. The CD_L
level can be muted (along with CD_R) or adjusted from +12 dB to -34.5 dB in 1.5 dB steps.
Stereo Mix 3D is mixed into the Stereo Mix signal at MIX2 for access to the stereo outputs
Line Out and Line Level Out.
AC Ground Reference
This input is the reference for the signals on both CD_L and CD_R. CD_GND is not a DC
ground and must be AC-coupled to the stereo source ground common to both CD_L and
CD_R. CD_GND, CD_L and CD_R act together as a quasi-differential stereo input such that
signals common to both CD_L and CD_R are rejected. This can improve the input SNR for a
stereo source with a good common ground but precision resistors may be needed in any
external attenuators to achieve the necessary balance between the two channels.
Right Stereo Channel Input
This line level input (1 Vrms nominal) is selectable at the right channel of the stereo Input
Mux for conversion by the right channel ADC. It can also be mixed into the right channel of
the Stereo Mix 3D signal at MIX1 under the control of the CD Volume register, 12h. The
CD_R level can be muted (along with CD_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 Line Level Out.
ANALOG I/O (Continued)
10