Other Parts Discussed in Thread: TINA-TI
Tool/software:
Hello,
My customer is looking for a solution to convert a 100Hz square wave to a 100Hz sine wave.
Could you please recommend a suitable device for this?
Thank you.
JH
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Hello JH,
There is a sine wave inside the square wave, just remove (filter out) all of the harmonics. Repeat as needed 2 pole op amp low pass filter stages.
sloa049d.pdf
Hi Michallick,
Thanks for your reply.
My customer wants a TI device and peripheral component values that can output a 100Hz sine wave signal of about 4V from a 100Hz square wave.
If there is a TI simulation tool like the ADI Tool below that allows users to input desired specifications and check product recommendations and peripheral values, please introduce it.
https://tools.analog.com/en/filterwizard/
BR,
JH
JH,
Yes we do here: https://webench.ti.com/filter-design-tool/filter-type
Hi Michallick,
Thanks for your help.
The customer has further questions about the simulation tool.
Q1. They want to input a source signal (100Hz square wave) to the circuit generated by the above filter tool and check the output signal. Do they have to use TINA-TI? Is there a simpler simulation tool than TINA-TI?
Q2. If TINA-TI is the only option, could you tell us how to generate a 100Hz square wave source? It would be nice if you could provide an example.
Q3. They said that they designed it with the filter design tool as shown below, but the Simulation Export button on the top left is not activated. Please tell us the cause of this symptom and how to solve it.
BR,
JH
JH,
The filter shown is not low pass and it doesn't work well at all. I re-did the filter and put it in Tina.
3.3 Logic Sqare wave to Sine wave.TSC
The gain for first 5 frequencies is listed in the table.
To help harmonic rejection a little and the prevent clipping, I attenuate the fundamental a little bit.
To compare fundamental with harmonics, I normalized values to 100Hz level.
I listed the natural square wave harmonic levels then computed the final ratios of the output.
F Hz | Gain | Normalized | Square | Final normal |
100 | -4.46 | 0.00 | 0.00 | 0.00 |
300 | -52.96 | -48.50 | -9.54 | -58.04 |
500 | -72.25 | -67.79 | -13.98 | -81.77 |
700 | -89.89 | -85.43 | -16.90 | -102.33 |
900 | -100.81 | -96.35 | -19.08 | -115.43 |
Square wave in and a decent quality sine wave out.
Hi Michallick,
I sincerely appreciate your kind support.
The customer requested additional example design for the case below. Can you help us?
- Supply voltage : +/- 3.3V, Input signal : 4V / 230KHz~250KHz square wave, Output : 6Vp-p 100Hz sine wave
BR,
JH
JH,
So output frequency = 100Hz + input * 0?
How 230KHz~250KHz become 100Hz please describe in detail?