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Trying to build a square wave generator (high frequency) and H-bridge Answered

Hi, I was wondering if someone could help me out at building a high frequency variable square wave generator. Specs: 100kHz - 1Mhz (better if I can get up to 3Mhz), 5 to 20V, square wave. Right now I have a LM555 timer. I have read online that I can get it to run at maximum 1Mhz. I don't know what I'm doing wrong, but I can't get it to output at higher frequencies. Also, does anyone know of a good H-bridge circuit schematic that could output 24V pk-pk at 3A. I will be using the signal from the square wave generator to feed to the H-bridge, therefore, is there a H-bridge design that can handle high frequencies? Or, is there another driver circuit that I could use instead of a H-bridge that could do the same job or better?


Thanks! for this curcial information ...can u suggest that how to generate center tapped pulses of 6Vac max of 1MHz or around it.


10 years ago

You may have to be careful about picking WHICH 555 timer you use if you want to get higher frequencies. TI says that their NE555 is only good up to 500kHz, while the TLC555 is good to 2MHz. In any case, 20V at 1MHz is a pretty substantial slew rate; I would suspect that you'd do better at lower voltages. Have fun interfering with everyone's RF devices. Don't get caught!

Thank you so much, I just bought the TLC555. I will try to set it up and see what frequencies I can get out of it. Also, with your help I was able to learn about Micrel MIC1555 timer. It can run at 5Mhz. Once again, thank you. Now I have to figure out the H-bridge. Sonny