LM4545 Datasheet | National Semiconductor

LM4545 AC ’97 Codec with Stereo Headphone Amplifier and National 3D Sound PRELIMINARY July 1999 LM4545 AC ’97 Codec with Stereo Headphone Amplifier and National 3D Sound General Description The LM4545 is an audio codec for PC systems which performs the analog-intensive function of the Analog Codec ’97 Rev 1.03 Architecture. Using 18-Bit Σ∆ A/D and D/A converters, the LM4545 provides 90d B 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/D’s and D/A’s 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 National’s 3D Sound stereo enhancement technology. The LM4545 Features AC-Link, a synchronous, fixed rate serial 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 increased overall performance. Key Specifications n Analog Mixer Dynamic Range n D/A Dynamic Range n A/D Dynamic Range n Headphone THD+N at 50m W into 32Ω 95d B (typ) 89d B (typ) 90d B (typ) 0.02% (typ) Features n Audio Codec ’97 pliant n Stereo 18-Bit Σ∆ A/D’s and D/A’s with 128X oversampling n Stereo headphone amp with separate gain control n National’s 3D Sound circuitry n Power management support n Digital Interface 3V and 5V pliant Applications n Desktop PC Audio Systems n Portable PC Audio Systems n Mobile PC Audio Solutions Block Diagram DS100069-1 FIGURE 1. LM4545 Block Diagram © 1999 National Semiconductor Corporation DS100069 .national....