LM4548 Datasheet, PDF (1/21 Pages) National Semiconductor (TI) – AC ’97 Rev 2 Codec with Sample Rate Conversion and National 3D Sound

OBSOLETE
LM4548
www.ti.com
SNOS441C – FEBRUARY 1999 – REVISED APRIL 2013
LM4548 AC '97 Rev 2 Codec with Sample Rate Conversion and TI 3D Sound
Check for Samples: LM4548
FEATURES
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•2 AC'97 Rev2 Compliant
• TI's 3D Sound Circuitry
• High Quality Sample Rate Conversion (SRC)
from 4kHz to 48kHz in 1Hz Increments.
• Multiple Codec Support
• True Line Level Output with Volume Control in
Addition to Standard Line Out
• Advanced Power Management Support
• Digital 3V and 5V Compliant
APPLICATIONS
• Desktop PC Audio Systems
• Portable PC Systems
• Mobile PC Systems
KEY SPECIFICATIONS
• Analog Mixer Dynamic Range: 97 dB (typ)
• D/A Dynamic Range: 89 dB (typ)
• A/D Dynamic Range: 90 dB (typ)
DESCRIPTION
The LM4548 is an audio codec for PC systems which
is fully PC98 compliant and performs the analog
intensive functions of the AC97 Rev2 architecture.
Using 18-bit Sigma-Delta A/D's and D/A's, the
LM4548 provides 90dB of Dynamic Range.
The LM4548 was designed specifically to provide a
high quality audio path and provide all analog
functionality in a PC audio system. It features full
duplex stereo A/D's and D/A's and an analog mixer
with 4 stereo and 3 mono inputs, each of which has
separate gain, attenuation and mute control. The
LM4548 also provides the additional True Line-Level
output and TI's 3D Sound stereo enhancement.
The LM4548 supports variable sample rate
conversion as defined in the AC97 Rev2
specification. The sample rate for the A/D and D/A
can be programmed separately to convert any rate
between 4kHz - 48kHz with a resolution of 1Hz. The
AC97 architecture separates the analog and digital
functions of the PC audio system allowing both for
system design flexibility and increased performance.
BLOCK DIAGRAM
Figure 1. LM4548 Block Diagram
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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