Connection Diagram

Pin Description

Analog I/O

Name

Pin

I / O

Functional Description

PC_BEEP

12

I

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.

PHONE

13

I

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.

AUX_L

14

I

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.

DS101035-2

Top View

Order Number LM4549VH

See NS Package Number VBH48A

www.national.com

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