lm4549a National Semiconductor Corporation, lm4549a Datasheet - Page 7

• Manufacturer Part Number: lm4549a
• Description: Ac ?97 Rev 2.1 Multi-channel Audio Codec With Sample Rate Conversion And National 3d Sound
• Manufacturer: National Semiconductor Corporation

Typical Application
APPLICATION HINTS
• The LM4549A must be initialized by using RESET# to perform a Power On Reset as shown in the Power On Reset Timing
• V
• Don’t leave unused inputs floating. Tie all unused inputs together and connect to Analog Ground through a capacitor (e.g. 0.1
• Do not leave CD_GND floating when using the CD stereo input. CD_GND is the AC signal reference for the CD channels and
• If using a non-standard AC Link controller take care to keep the SYNC and SDATA_IN signals low during Cold Reset to avoid
• The PC_Beep input should be muted if not used since it defaults to 0 dB gain on reset, unlike the mute default of the other
Diagram
µF)
should be connected to the CD source ground (Analog Ground may also be acceptable) through a 1 µF capacitor
entering the ATE or Vendor test modes by mistake
analog inputs
REF
must be pulled high to AV
FIGURE 1. LM4549A Typical Application Circuit, Single Codec, 1 Vrms inputs
DD
with a 10 kΩ resistor to ensure correct operation
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