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square waveform->sine waveform

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leacom

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square to sine

any advice?
about 100kHz, little phase error is preferred

thanks in advance
 

circuits sine waveform

Use Gaussian or Bessel type , Minimum Phase Lag filters. They can be active or if the voltage and/or current is high , should be passive.
 

triangle from square waveform filter

Here are some more tricks.

Use notch filters on the 3rd and 5th harmonic. This will produce less delay.

Make a PLL. Heavily filter the VCO output to get a pure sine wave. Feed the sine wave to both your wanted output and also a comparator to get a square wave again. Feed this comparator output back to the phase detector. If you use a frequency/phase detector, you will get zero degree difference between the sine wave and the original square wave.

Use whatever filter it takes to get the sine wave purity you need. Then put the square wave signal through a delay circuit of equal delay before sending it to the destination. This delay circuit can be a first monostable to make the delay and it triggers a second monostable which makes the positive half of the square wave.
 

simple sine waveform circuit

if the application need pure sine a filter over the required harmonic is the good solution and with PLL as descriped if the phase is concerened. if you need a smi sine you can use an integrator.
 

square to sine waveform

most accuracy methode is uses digital way, ClockGen + Sine Wave Table + DAC + LPF
 

square waveform to sine

Good results can be obtained using a weighted diode-resistor clamp structure. This is often used in low-end function generators where distortion is not ultra important.
 

sine square waveform

E-design said:
Good results can be obtained using a weighted diode-resistor clamp structure. This is often used in low-end function generators where distortion is not ultra important.

This method is used in some older Exar ICs. You can look at their data sheets and also older books on pulse and timing circuits. In general you form a voltage divider with the shunt to ground being a series set of diodes with resistors from each junction to ground plus the last diode with a resistor to ground. You drive it with a triangle wave and as the voltage rises more diodes turn on and connect more shunt resistors which reduces the "gain" of the voltage divider. This rounds off the top of the triangle wave. You can get 1% distortion or better with enough diodes.
 

sine wave form a vco

A simple solution is to take a switched-capacitor lowpass filter.
You can easily change your output frequency without the need to modify any components.
See for ex. **broken link removed**
 

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