Ac’97 Codec With Stereo Headphone Amplifier And National 3d Sound - National Semiconductor

The LM4545 is an Audio CODEC for PC systems which per- forms the analog-intensive function of the Analog Codec 97 Rev 1.03 Architecture. Using 18-Bit A/D and D/A convert- ers, the LM4545 provides 90dB of dynamic range. The LM4545 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/Ds and D/As and an Analog mixer with 4 stereo and 3 mono inputs, each of which has separate gain, attenuation and mute control. In addition, the LM4545 provides a stereo Headphone Amplifier with an independent gain control and Nationals 3D Sound stereo enhancement technology. The LM4545 features AC-Link, a synchronous, fixed rate se- rial bus for connection to the digital AC 97 Controller. The separation of the Analog and digital functions of the AC 97 architecture allows for system design flexibility and in- creased overall performance. By National Semiconductor Corporation