Hi
I am building up an amplifier with an active high pass filter at the input of the op-amp,
The amplifier will run at low frequency, approximately 1khz to 2khz
the mean purpose of this high pass filter is to remove the DC-offset in the signal.
I have been advised to use a large capacitor, and I have realised that the with small capacitors, the output square wave is more likely to be distorted. something like this
Could anyone please explain me why this is happening? is that because the capacitor is too small, so that the capacitor is charges up too quickly? or because it is too small, it is discharged too quickly?
I have also been advised that the value of the capacitor is related to the impedance, for my case the lower the input impedance, the better it is. (hence, large capacitor )
This confuses me a lot, because low input impedance means short circuit, then what's the difference between having a wire directly connected to the input or have this high pass filter circuit?
Many thanks for your kind help !
I am building up an amplifier with an active high pass filter at the input of the op-amp,
The amplifier will run at low frequency, approximately 1khz to 2khz
the mean purpose of this high pass filter is to remove the DC-offset in the signal.
I have been advised to use a large capacitor, and I have realised that the with small capacitors, the output square wave is more likely to be distorted. something like this
Could anyone please explain me why this is happening? is that because the capacitor is too small, so that the capacitor is charges up too quickly? or because it is too small, it is discharged too quickly?
I have also been advised that the value of the capacitor is related to the impedance, for my case the lower the input impedance, the better it is. (hence, large capacitor )
This confuses me a lot, because low input impedance means short circuit, then what's the difference between having a wire directly connected to the input or have this high pass filter circuit?
Many thanks for your kind help !