SI477X-EVB Datasheet, PDF (30/62 Pages) Silicon Laboratories – Complete antenna-to-audio evaluation system

Si477x-EVB
6.3.3. Headphone Amplifier/Buffer
Left and Right audio outputs are buffered and lowpass filtered by on-board amplifiers in Figure 33. “Audio Output”.
The software automatically selects the L/R audio-band output when AM or FM modes are selected. The left
channel/MPX output is selected in MPX mode only.
Unbuffered L/R outputs are available at the debug header J48.
Note: Use L/R outputs directly from tuner for THD, SINAD, and stereo imbalance measurements. The headphone amplifier
may degrade performance.
The analog L/R and MPX outputs are available at two 3.5 mm jacks. The function of each jack varies by baseboard
revision.
The left jack is a direct, dc-coupled L/R/MPX output from the tuner. This output should be used for all low-distortion
laboratory measurements. The right jack is an ac-coupled, unity-gain-buffered L/R output for listening through
headphones or powered speakers.
Figure 33. Audio Output
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Rev. 0.4