STAC9750 Datasheet, PDF (5/73 Pages) Integrated Device Technology – VALUE-LINE TWO-CHANNEL AC’97 CODECS

STAC9750/9751
VALUE-LINE TWO-CHANNEL AC’97 CODECS
PC AUDIO
1. PRODUCT BRIEF
1.1.
Features
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Full duplex stereo 18-bit ADC and 20-bit DAC
AC’97 Rev 2.2-compliant
High performance Σ∆ technology
SPDIF output
Crystal elimination circuit
Headphone amplifier
Independent sample rates for ADCs & DACs (hardware SRCs)
20dB or 30dB microphone boost capability
90dB SNR LINE-LINE
5-Wire AC-Link protocol compliance
Digital-Ready architecture
General Purpose I/O
+3.3 V (STAC9751) and +5 V (STAC9750) analog power supply options
Pin compatible with the STAC9700/21/44/08/56/66/52
IDT Surround (SS3D) Stereo Enhancement
Energy saving dynamic power modes
1.2. Description
IDT's STAC9750/9751 are general purpose 18-bit ADC, 20-bit DAC, full duplex, audio CODECs con-
forming to the analog component specification of AC'97 (Audio Codec ‘97 Component Specification
Rev. 2.2). The STAC9750/9751 incorporate IDT's proprietary Σ∆ technology to achieve a DAC SNR
in excess of 90 dB. The DACs, ADCs, and mixer are integrated with analog I/Os, which include four
analog line-level stereo inputs, two analog line-level mono inputs, two stereo outputs, and one mono
output channel. The STAC9750/9751 include digital input/output capability for support of modern PC
systems with an output that supports the SPDIF format. The STAC9750/9751 is a standard 2-chan-
nel stereo CODEC. With IDT’s headphone drive capability, headphones can be driven with no exter-
nal amplifier. The STAC9750/9751 may be used as a secondary CODEC, with the STAC9700/21/44/
56/08/84/66 as the primary, in a multiple CODEC configuration conforming to the AC'97 Rev. 2.2
specification. This configuration can provide the true six-channel, AC-3 playback required for DVD
applications. The STAC9750/9751 communicates via the five-wire AC-Link to any digital component
of AC'97, providing flexibility in the audio system design. Packaged in an AC'97 compliant 48-pin
LQFP, the STAC9750/9751 can be placed on a motherboard, daughter boards, PCI, AMR, CNR, or
ACR cards.
The STAC9750/9751 block diagram is illustrated in Figure 1. It provides variable sample rate Digi-
tal-to-Analog (DA) and Analog-to-Digital (AD) conversion, mixing, and analog processing. Supported
audio sample rates include 48 KHz, 44.1 KHz, 32 KHz, 22.05 KHz, 16 KHz, 11.025 KHz, and 8 KHz;
additional rates are supported in the STAC9750/9751 soft audio drivers. The digital interface com-
municates with the AC'97 controller via the five-wire AC-Link and contains the 64-word by 16-bit reg-
IDT™
VALUE-LINE TWO-CHANNEL AC’97 CODECS
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STAC9750/9751
V 5.8 103106