Sallen-Key, Multiple Feedback, State Variable, and Biquad Filters

filter
op amp
sallen key
biquad
state variable

This page compares the Sallen-Key filter, multiple feedback filter, state variable filter, and Biquad filter. It discusses low-pass and high-pass equivalents of these second-order filter types, specifically covering:

  • Sallen-Key low-pass filter
  • Sallen-Key high-pass filter
  • Multiple feedback low-pass filter
  • Multiple feedback high-pass filter
  • 2-pole state variable filter
  • Standard 2-pole Biquad filter and its high-pass equivalent

All of these filters are based on operational amplifier (Op-Amp) configurations, using both inverting and non-inverting combinations.

Sallen-Key Low-Pass Filter

sallen key filter low pass type

Figure 1: Sallen-Key Low-Pass Filter

Figure 1 shows a Sallen-Key low-pass filter using an Op-Amp and includes its transfer function.

Sallen-Key High-Pass Filter

sallen key filter low pass and high pass type

Figure 2: Sallen-Key High-Pass Filter

Figure 2 illustrates a Sallen-Key high-pass filter with 2 poles, as well as the low-pass equivalent of the design.

Multiple Feedback Low-Pass Filter

multiple feedback filter low pass type

Figure 3: Multiple Feedback Low-Pass Filter

Figure 3 depicts a multiple feedback filter configured as a low-pass filter.

Multiple Feedback High-Pass Filter

multiple feedback filter high pass type

Figure 4: Multiple Feedback High-Pass Filter

Figure 4 shows a multiple feedback filter implemented as a high-pass filter.

State Variable Filter (2-Pole)

state variable filter

Figure 5: State Variable Filter (2-Pole)

Figure 5 illustrates a 2-pole state variable filter.

Biquad Filter (2-Pole)

Biquad filter

Figure 6: Biquad Filter (2-Pole)

Figure 6 shows a standard 2-pole Biquad filter, including a high-pass filter configuration of the Biquad type.

5G mmWave Filter Specifications and Manufacturers

5G mmWave Filter Specifications and Manufacturers

Explore the technical specifications of 5G mmWave filters, including bandwidth, frequency range, and insertion loss. Discover leading manufacturers in this rapidly evolving field.

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