The LM4549B device is an audio codec for PC systems which is fully compliant with the PC99 and performs the analog intensive functions of the AC ’97 Rev 2.1 architecture. Using 18-bit sigma-delta ADCs and DACs, the LM4549B provides 90 dB of dynamic range.
The LM4549B 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 ADCs and DACs and analog mixers with access to 4 stereo and 4 mono inputs. Each mixer input has separate gain, attenuation and mute control and the mixers drive 1 mono- and 2-stereo outputs, each with attenuation and mute control. The LM4549B supports Texas Instrument’s 3D Sound stereo enhancement and a comprehensive sample rate conversion capability. The sample rate for the ADCs and DACs can be programmed separately with a resolution of 1 Hz to convert any rate in the range 4 kHz – 48 kHz. Sample timing from the ADCs and sample request timing for the DACs are completely deterministic to ease task scheduling and application software development. These features together with an extended temperature range also make the LM4549B suitable for non-PC codec applications.
The LM4549B features the ability to connect several codecs together using the Extended AC Link configuration of one dedicated serial data signal to the Controller per codec. LM4549B systems support up to 8 simultaneous channels of streaming data on Input Frames (Codec to Controller) while Output Frames (Controller to Codec) carry 2 streams to multiple codecs. The LM4549B may also be used in systems with the Texas Instruments LM4550B to support up to 6 simultaneous channels of streaming data on Output Frames.
The AC ’97 architecture separates the analog and digital functions of the PC audio system allowing both for system design flexibility and increased performance.
| Type | Title | Date | ||
|---|---|---|---|---|
| * | Data sheet | LM4549B AC '97 Rev 2.1 Multi-Channel Audio Codec With Sample Rate Conversion and TI 3D Sound datasheet (Rev. B) | PDF | HTML | 01 Jul 2015 |
| Application note | Out-of-Band Noise Measurement Issues for Audio Devices (Rev. A) | 31 Dec 2019 | ||
| Application note | Audio Serial Interface Configurations for Audio Codecs (Rev. A) | 27 Jun 2019 | ||
| Application note | Using the MSP430 Launchpad as a Standalone I2C Host for Audio Products (Rev. A) | 28 Oct 2013 | ||
| Application note | Audio Serial Interface Configurations for Audio Codecs | 22 Sep 2010 | ||
| Application note | Solving Enumeration Errors in USB Audio DAC and CODEC Designs | 30 Oct 2009 | ||
| Application note | Configuring I2S to Generate BCLK from Codec Devices & WCLK from McBSP Port | 08 Jul 2009 |
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| Package | Pins | CAD symbols, footprints & 3D models |
|---|---|---|
| LQFP (PT) | 48 | Ultra Librarian |
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