LM4549 National Semiconductor, LM4549 Datasheet - Page 7

• Manufacturer Part Number: LM4549
• Description: AC 97 Rev 2.1 Codec with Sample Rate Conversion and National 3D Sound
• Manufacturer: National Semiconductor

Connection Diagram
Pin Description
Analog I/O
PC_BEEP
PHONE
AUX_L
Name
Pin
12
13
14
I / O
I
I
I
Functional Description
This is a mono input which gets summed into both the stereo line out and the true line level
out after the National 3D Sound block. The PC_BEEP level can be adjusted from 0dB to
−45dB in 3dB steps, or muted, via register 0Ah. This input is directly connected to the line
output while the reset pin is held active low to allow power on self test tones to be heard
through the audio system.
This is a mono input which gets summed into both the stereo line out and the true line level
out after the National 3D Sound block. The PHONE level can be adjusted from +12dB to
−34.5dB in 1.5dB steps as well as muted via register 0Ch.
This line level input can be routed through the Input Mux and recorded by the left ADC. In
addition, this analog input gets summed into the left output stream. The amount of AUX_L
signal mixed in the left output stream can be adjusted from +12dB to −34.5dB in 1.5dB steps
as well as muted via register 16h.
See NS Package Number VBH48A
Order Number LM4549VH
Top View
7
DS101035-2
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