lm4550 National Semiconductor Corporation, lm4550 Datasheet - Page 9

• Manufacturer Part Number: lm4550
• Description: Ac ?97 Rev 2.1 Multi-channel Audio Codec With Stereo Headphone Amplifier, Sample Rate Conversion And National 3d Sound
• Manufacturer: National Semiconductor Corporation

Connection Diagram
Pin Descriptions
PC_BEEP
VIDEO_L
PHONE
AUX_R
AUX_L
Name
Pin
12
13
14
15
16
I / O
I
I
I
I
I
Functional Description
This is a mono input which gets summed into both the stereo line out and stereo headphone
output 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 stereo headphone
output 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.
This line level input can be routed through the Input Mux and recorded by the right ADC. In
addition, this analog input gets summed into the right output stream. The amount of AUX_R
signal mixed in the right output stream can be adjusted from +12dB to −34.5dB in 1.5dB
steps as well as muted via register 16h.
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 VIDEO_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 14h.
See NS Package Number VBH48A
Order Number LM4550VH
ANALOG I/O
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