Filters are often described using low-pass prototypes, as low-pass is the standard configuration. A high-pass filter can be thought of as a side-connected low-pass filter. The DC response is not flat due to the origin zero, but rather a rising response of n×(20dB/decade), where n is the number of poles. At the corner frequency, this rising response is increased by n×(–20dB/decade) due to the poles. The result is a flat response outside the corner frequency. Scaling the transfer function by 1/s converts the low-pass prototype into a high-pass filter. In practice, this is usually equivalent to turning a capacitor into an inductor of 1/C, or for a passive design, turning an inductor into a capacitor of 1/L. For an active design, a resistor becomes a capacitor of 1/R, and a capacitor becomes a resistor of 1/C. This only applies to frequency setting resistors, not gain setting resistors (i.e., not every resistor or capacitor in the circuit).
You Might Like
Recommended ContentMore
Open source project More
Popular Components
Searched by Users
Just Take a LookMore
Trending Downloads
Trending ArticlesMore