LM4546AVH NSC [National Semiconductor], LM4546AVH Datasheet - Page 10

• Manufacturer Part Number: LM4546AVH
• Description: AC 97 Rev 2 Multi-Channel Audio Codec with Sample Rate Conversion and National 3D Sound
• Manufacturer: NSC [National Semiconductor]

www.national.com
LINE_OUT_L
LINE_IN_R
LINE_IN_L
Name
CD_R
MIC1
MIC2
Pin
20
21
22
23
24
35
I / O
O
I
I
I
I
I
Functional Description
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.
Mono microphone input
Either MIC1 or MIC2 can be muxed to a programmable boost amplifier with selection by the MS
bit (bit D8) in the General Purpose register, 20h. The boost amplifier gain (0 dB or 20 dB) is set by
the 20dB bit (D6) in the Mic Volume register, 0Eh. Nominal input levels at the two gain settings are
1 Vrms and 0.1 Vrms respectively. The amplifier output is selectable (Record Select register, 1Ah)
by either the right or left channels of the Record Select Mux for conversion on either or both
channels of the stereo ADCs. The amplifier output can also be accessed at the stereo mixer MIX1
(muting and mixing adjustments via Mic Volume register, 0Eh) where it is mixed equally into both
left and right channels of Stereo Mix 3D for access to the stereo outputs Line Out and Line Level
Out. Access to the Mono analog output is selected by a mux controlled by the MIX bit (D9) in
General Purpose register, 20h.
Mono microphone input
Either MIC1 or MIC2 can be muxed to a programmable boost amplifier with selection by the MS
bit (bit D8) in the General Purpose register, 20h. The boost amplifier gain (0 dB or 20 dB) is set by
the 20dB bit (D6) in the Mic Volume register, 0Eh. Nominal input levels at the two gain settings are
1 Vrms and 0.1 Vrms respectively. The amplifier output is selectable (Record Select register, 1Ah)
by either the right or left channels of the Record Select Mux for conversion on either or both
channels of the stereo ADCs. The amplifier output can also be accessed at the stereo mixer MIX1
(muting and mixing adjustments via Mic Volume register, 0Eh) where it is mixed equally into both
left and right channels of Stereo Mix 3D for access to the stereo outputs Line Out and Line Level
Out. Access to the Mono analog output is selected by a mux controlled by the MIX bit (D9) in
General Purpose register, 20h.
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 Line In Volume register, 10h. The LINE_IN_L level
can be muted (along with LINE_IN_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 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 Line In Volume register, 10h. The LINE_IN_R level can
be muted (along with LINE_IN_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 Output
This line level output (1 Vrms nominal) is fed from the left channel of the Stereo Mix signal from
MIX2 via the Master Volume register, 02h. The LINE_OUT_L amplitude can be muted (along with
LINE_OUT_R) or adjusted from 0 dB to -46.5 dB in 1.5 dB steps.
200308 Version 5 Revision 1
Print Date/Time: 2009/07/15 15:26:52
10