For example, a programmable second-order, low-pass Butterworth filter with a corner frequency ranging from 200 Hz to 20 kHz can be designed by setting C1 = 0.022 µF and C2 = 0.1 µF. The values ...

There’s also a low-pass filter that’s controlled by a couple of light-dependent resistors, which can be played by blocking them off with a fingertip.

Requiring high-frequency noise suppression, GSM mobile phone applications are demanding smaller and lower cost low-pass filters to replace conventional low-pass filter circuits, said the company. FDK ...

The audio circuitry from the Raspberry Pi 3. The low-pass filter’s 220R and 100nF now give it a cut-off of just over 7kHz, and the high-pass filter’s 100R and 47uF give it 33Hz.

This circuit provides the desired high-pass function, removing the microphone's dc offset and adds in the dc offset required by the ADC. The high input impedance of the non-inverting operational ...