STAC9750 Datasheet, PDF (6/73 Pages) Integrated Device Technology – VALUE-LINE TWO-CHANNEL AC’97 CODECS

STAC9750/9751
VALUE-LINE TWO-CHANNEL AC’97 CODECS
PC AUDIO
isters. The two DACs convert the digital stereo PCM-out content to audio. The MIXER block
combines the PCM_OUT with any analog sources, to drive the LINE_OUT and HP_OUT outputs.
The MONO_OUT delivers either microphone only, or a mono mix of sources from the MIXER. The
stereo variable sample rate ADCs provide record capability for any mix of mono or stereo sources,
and deliver a digital stereo PCM_IN signal back to the AC-Link. The microphone input and mono
input can be recorded simultaneously, thus allowing for an all digital output in support of the digital
ready initiative. All ADCs operate at 18-bit resolution and DACs at 20-bit resolution. For a digital
ready record path, the microphone is connected to the left channel ADC while the mono output of the
stereo mixer is connected to right channel ADC. Make sure the microphone input is not connected to
the stereo mixer when in this mode.
The STAC9750/9751 supports General Purpose Input/Output (GPIO), as well as SPDIF output.
These digital I/O options provide for a number of advanced architectural implementations, with vol-
ume controls and digital mixing capabilities built directly into the CODEC.
The STAC9750/9751 is designed primarily to support stereo (2-speaker) audio. True AC-3 playback
can be achieved for 6-speaker applications by taking advantage of the multi-CODEC option avail-
able in the STAC9750/9751 to support multiple CODECs in an AC'97 architecture. Additionally, the
STAC9750/9751 provides for a stereo enhancement feature, IDT Surround 3D (SS3D). SS3D pro-
vides the listener with several options for improved speaker separation beyond the normal 2/
4-speaker arrangements.
Together with the logic component (controller or advanced core logic chip-set) of AC'97, STAC9750/
9751 can be SoundBlaster^® and Windows Sound System^® compatible with IDT’s WDM driver for
WIN 98/2K/ME/XP.
SoundBlaster is a registered trademark of Creative Labs.
Windows is a registered trademark of Microsoft Corporation.
1.3.
STAC9750/9751 Block Diagram
AC-link
SYNC
BIT_CLK
SDATA_OUT
SDATA_IN
RESET#
Multi-Codec
CID0
CID1
Figure 1. STAC9750/9751 Block Diagram
Power
Management
4 stereo
sources
PCM out DACs
2 mono
sources
Stereo
Mono
DAC
Digital
DAC
Interface
MIXER
HP_OUT
LINE_OUT
Registers
64x16 bits
ADC
ADC
Analog mixing ^MONO_OUT
and Gain Control
PCM in ADCs
Mic Boost
0,20 or 30 dB
Variable Sample Rate
20-Bit DACs and
18-Bit ADCs
SPDIF
M _MIC1
U
X
MIC2
IDT™
VALUE-LINE TWO-CHANNEL AC’97 CODECS
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STAC9750/9751
V 5.8 103106