Connection Diagram

20029902

Top View

Order Number LM4549AVH

See NS Package Number VBH48A

Pin Descriptions

ANALOG I/O

Name

Pin

I / O

Functional Description

PC_BEEP

12

I

Mono Input

This line level (1 Vrms nominal) mono input is mixed equally into both channels of the Stereo

Mix signal at MIX2 under the control of the PC_Beep Volume control register, 0Ah. The

PC_BEEP level can be muted or adjusted from 0 dB to -45 dB in 3 dB steps. The Stereo Mix

signal feeds both the Line Out and Line Level Out analog outputs and is also selectable at

the Record Select Mux. During Initialization or Cold Reset, (reset pin held active low),

PC_BEEP is switched directly to both channels of the Line Out stereo output, bypassing all

volume controls. This allows signals such as PC power-on self-test tones to be heard through

the PC’s audio system before the codec registers are configured.

PHONE

13

I

Mono Input

This line level (1 Vrms nominal) mono input is selectable at the Record Select Mux for

conversion by either channel of the stereo ADC. It can also be mixed equally into both

channels of the Stereo Mix signal at MIX2 under the control of the Phone Volume register,

0Ch. The PHONE level can be muted or adjusted from +12 dB to -34.5 dB in 1.5 dB steps.

The Stereo Mix signal feeds both the Line Out and Line Level Out analog stereo outputs and

is also selectable at the Record Select Mux.

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