Fifth-Order Low-Pass Filter Circuit Diagram

Introduction

A fifth-order low-pass filter circuit is a type of electronic circuit used to filter out unwanted high-frequency signals, allowing only the lower frequencies to pass through the amplifier. It works by passing an incoming signal through five main stages of operation: first, it blocks any DC signals from getting through; second, it allows only the desired low frequencies to pass; third, it effectively filters out those frequencies that are higher than the cutoff frequency set by the fifth stage; finally, some additional amplification is provided by the final stage. This type of circuit is ideal for audio applications as it can effectively reduce external noise and hums during recording or playback.

Circuit Diagram

of Fifth-Order Low-Pass Filter Circuit

More Circuit Layouts

Working Explanation

of Fifth-Order Low-Pass Filter Circuit

The LTC1062 is an integrated 5th-order lowpass filter that stands out through the absence of any d.c. blunders. This is achieved by keeping the actual filter outside the d.c. range to eliminate matters like d.c. offset and low-frequency interference. It, therefore, makes the ltc1062 eminently suitable for filtering out packages wherein d.C. errors cannot be tolerated. A pivotal role in this is played by external resistor R5. The output signal is fed back to the input of the filter via external capacitor C4. Network R5-C4, in association with the internal switched-capacitor network, provides the fifth-order low-pass function.

The cut-off frequency of the filter is determined by an internal clock that can be controlled externally. This control is provided by oscillator IC1, which is configured as an astable multivibrator (AMV). The filter has an internal divider that can be set for a scaling factor of 1, 2, or 4. In the present circuit, this factor is set to 4, resulting in a cut-off frequency equal to 1/400 of the clock frequency. Since the clock here is 4 kHz, the cut frequency is 10 Hz. If a different cut-off frequency is wanted, R5, R6, C4, and C5 must meet the following requirement to retain a smooth pass band.

1/2nR5C4=fc/1.84,
provided that C4=C5 and R6=12R5.
R1, R2, P1 and C2 must satisfy the following requirement
R1C2=1.4/3400fc’
provided that R2=R1/2 and P1=R1.

Conclusion

A low-pass filter is a type of electronic filter used in various applications, such as audio devices and recording equipment. It removes signals with too much frequency content from the original signal, allowing only those signals within a specific frequency range to pass through. This results in a smoother, more consistent sound that has less background noise. It's also useful for eliminating certain frequencies that may be interfering with other devices or instruments connected to the same source. Low-pass filters are usually adjustable, so you can tweak them to suit your particular needs and taste. They can make all the difference when it comes to creating high-quality recordings or sounds with clarity and definition.