Buffer Capacitors


What does a buffer do?
In the given circuit,it is said that capacitors C1 and C4 act as buffer .What is their role here?Can't we just replace them with pull-down resisrors?
Speaker Circuit

Best Answer

For reference the TDA2822M datasheet can be found here.

Those capacitors are connected to the power supply pin (pin #2). They are acting as bypass capacitors. Bypass capacitors are designed to remove AC noise from the DC supply voltage. Since capacitors are a short at high frequencies, high frequency noise is shorted to ground while the DC supply voltage is passed.

You would not want to replace them with pull-down resistors. You don't want to pull down the supply voltage, and if you replaced them high frequency noise would be passed to the supply pin of the IC.

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