Hi,

I am new to electronics field. I am making a square wave, the problem in my design is that i am getting spikes or noise in starting of each new cycle of square wave. Please help me to improve my circuit.

Thanks
Lee

 

So, lets see the your circuit...

 

Uncalibrated probe tips can also produce spikes that are not really there. Test instruments can and do lie like rug.

 

Spikes in square waves are often caused by stray inductance in the circuit. The best option is to reduce the inductance by keeping the wires short, close together and larger size. Also adding a filter capacitor close to the switching elements will help minimize the effect of the inductance. If this is not enough, then add an RC snubber across your switching elements. The values for the capacitance and resistance depend largely on the swithcing frequency and the voltage levels. I usually model the circuit and try different values to obtain the optimum results. Hope this helps.