Product Summary

The LM4548 is an audio codec for PC systems which is fullyPC98 compliant and performs the analog intensive functionsof the AC97 Rev2 architecture. Using 18-bit Sigma-DeltaA/D’s and D/A’s, the LM4548 provides 90dB of DynamicRange.The LM4548 was designed specifically to provide a highquality audio path and provide all analog functionality in a PCaudio system. It features full duplex stereo A/D’s and D/A’sand an analog mixer with 4 stereo and 3 mono inputs, eachof which has separate gain, attenuation and mute control.The LM4548 also provides the additional True Line-Leveloutput and National’s 3D Sound stereo enhancement.The LM4548 supports variable sample rate conversion asdefined in the AC97 Rev2 specification. The sample rate forthe A/D and D/A can be programmed separately to convertany rate between 4kHz - 48kHz with a resolution of 1Hz. TheAC97 architecture separates the analog and digital functionsof the PC audio system allowing both for system design flex-ibility and increased performance.


Specifications of LM4548VHNOPB Single Supply Voltage (typ) 3.3/5V Single Supply Voltage (min) 3/4.2V Single Supply Voltage (max) 5.5V Package Type LQFP Lead Free Status / RoHS Status Compliant


hAnalog Mixer Dynamic RangehD/A Dynamic RangehA/D Dynamic RangeFeaturesn AC’97 Rev2 compliantn National’s 3D Sound circuitryn High quality Sample Rate Conversion (SRC) from 4kHzto 48kHz in 1Hz increments.n Multiple Codec Supportn True Line Level Output with volume control in addition tostandard Line Outn Advanced power management supportn Digital 3V and 5V compliantApplicationsn Desktop PC Audio Systemsn Portable PC Systemsn Mobile PC Systems