Question

In a low pass butterworth filter, the condition at which f=fH is called

(a) Cut-off frequency

(b) Break frequency

(c) Corner frequency

(d) All of the mentioned

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This interesting question is from First Order Low Pass Butterworth Filter in division Active Filters of Linear Integrated Circuits

Answer 1

In the context of a Low Pass Butterworth Filter, the condition at which the frequency f=fHf = f_Hf=fH​ is typically referred to as the cut-off frequency. This is the point where the filter's output starts to significantly attenuate (at -3 dB, or 12\frac{1}{\sqrt{2}}2​1​ of the maximum passband gain).

Key Terms:

• Cut-off frequency: The frequency at which the output signal begins to drop off, often defined as the point where the gain falls to 3 dB below its maximum value.

• Break frequency: This term is sometimes used interchangeably with cut-off frequency, but it's more commonly associated with certain filters or specific contexts.

• Corner frequency: This term is also often used synonymously with cut-off frequency, especially in the context of filters.

Thus, the correct answer for the frequency condition at f=fHf = f_Hf=fH​ in a Low Pass Butterworth Filter is:

(a) Cut-off frequency

This term is the most widely used and standard term for the frequency where the filter's response begins to attenuate.