The LM4550B must be initialized by using RESET# to perform a Power On Reset as shown in the Power On Reset Timing Diagram
Don't leave unused Analog inputs floating. Tie all unused inputs together and connect to Analog Ground through a capacitor (for example, 0.1 µF)
Do not leave CD_GND floating when using the CD stereo input. CD_GND is the AC signal reference for the CD channels and should be connected to the CD source ground (Analog Ground may also be acceptable) through a 1-µF capacitor
If using a non-standard AC Link controller take care to keep the SYNC and SDATA_OUT signals low during Cold Reset to avoid accidentally activating the ATE or Vendor test modes
The PC_Beep input should be explicitly muted if not used because it defaults to 0-dB gain on reset, unlike the mute default of the other analog inputs