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AS1702, AS1703, AS1704, AS1705

Data Sheet

Layout and Grounding Considerations

7.4.2 Input Filter

The BTL inputs can be biased at voltages other than mid-supply. However, the integrated common-mode feedback cir-

cuit adjusts for input bias, ensuring the outputs are still biased at mid-supply. Input capacitors are not required if the

ing signal. The AC coupling capacitor allows the amplifier to bias the signal to an optimum DC level. Assuming zero-

source impedance, the -3dB point of the high-pass filter is given by:

age coefficients such as tantalum or aluminum electrolytic should be used, since capacitors with high-voltage coeffi-

cients, such as ceramics, can increase distortion at low frequencies.

7.4.3 BIAS Capacitor

and THD+N by reducing power supply noise and other noise sources at the common-mode bias node, and also gener-

ates the click- and pop-less DC bias waveform for the amplifiers. Bypass BIAS with a 0.1µF capacitor to GND. Larger

Note: Do not connect external loads to BIAS.

7.4.4 Supply Bypassing

low-distortion performance of the device. Additional bulk capacitance can be added as required.

7.5 Layout and Grounding Considerations

Well designed PC board layout is essential for optimizing device performance. Use large traces for the power supply

inputs and amplifier outputs to minimize losses due to parasitic trace resistance and route heat away from the device.

Good grounding improves audio performance and prevents digital switching noise from coupling onto the audio signal.

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