Dear All,
I'm building a DSP circuit using the ADAU1701 from Analogue Devices. It has two analogue inputs, of which the datasheet states:
"The 47 μF capacitors are used to ac-couple the signals so that the inputs are biased at 1.5 V".
I am wondering what would be the effect of using a capacitor of a smaller value e.g. 10uF or 22uF? Am I right in thinking that these caps are to block any DC current? If so then surely a much smaller value cap would suffice since DC signals don't have a frequency? The other thing to bear in mind is this circuit will be used for audio signals only, so any frequencies below 20Hz could be safely blocked.
Any help in my understanding of this concept would be much appreciated.
I attach the relevant excerpt from the datasheet.
I'm building a DSP circuit using the ADAU1701 from Analogue Devices. It has two analogue inputs, of which the datasheet states:
"The 47 μF capacitors are used to ac-couple the signals so that the inputs are biased at 1.5 V".
I am wondering what would be the effect of using a capacitor of a smaller value e.g. 10uF or 22uF? Am I right in thinking that these caps are to block any DC current? If so then surely a much smaller value cap would suffice since DC signals don't have a frequency? The other thing to bear in mind is this circuit will be used for audio signals only, so any frequencies below 20Hz could be safely blocked.
Any help in my understanding of this concept would be much appreciated.
I attach the relevant excerpt from the datasheet.
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