LM4546 - National Semiconductor

LM4546 AC97 Codec

The LM4546 is an audio codec for PC systems which is fully PC98 compliant and performs the analog intensive functions of the AC97 Rev 2 architecture. Using 18-bit Sigma-Delta A/D’s and D/A’s, the LM4546 provides 90dB of Dynamic Range. The LM4546 was designed specifically to provide a high quality audio path and provide all analog functionality in a PC audio .

Features

full duplex stereo A/D’s and D/A’s and an analog mixer with 2 stereo and 3 mono inputs, each of which has separate gain, attenuation and mute control. The LM4546 also provides National’s 3D Sound stereo enhancement. The LM4546 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.