• Resolved

# looking for conversion of clipped sine wave to square wave conversion

Hi Team

I need one Part number which can convert the clipped sine wave  ( 1MHz and 10 Mhz ) (0.7pk to pk) to Square wave (5V) .

Regards

Nitesh

• "Clipped" would imply that the signal goes from rail to rail, but then it would not be 0.7 V peak-to-peak.

If the signal were guaranteed to go both below and above the low and high input thresholds, you could use a Schmitt-trigger buffer. With something like the SN74LVC1G17, this would require a swing of at least about 1.5 V. (And if the input signal is not symmetrical about the threshold, the output does not have a 50 % pulse width.)

With such a small amplitude, you have to use a comparator (e.g., TLV3201).

• Hey Nitesh,

In addition to what Clemens suggested, I think you could use an SN74LVC1GX04 to accomplish this.  This device is usually used to drive a crystal oscillator, and the output of most crystals is a fairly small sine wave (0.5 to 1V in my experience).

The input needs to be AC coupled (add a series capacitor, 0.1uF should work well), then connect directly to the X1 input. Add a feedback resistor from X2 to X1 to provide the appropriate bias -- 100k to 1M should work well.

Then your output shows up at Y.

You may have to tweak some passive values, but the circuit is relatively simple and only requires one ic.

#### The Logic Minute training page has videos on many interesting topics that all are kept shorter than 5 minutes.

• In reply to Emrys Maier:

Nitesh

Please provide a picture of the waveform that you want to convert to 5v. Ideally this would be an oscilloscope screen shot so everyone can see the common mode voltage level and signal swing. From your original post it sounds like the amplitude is 0.7v pk-pk but it’s best to confirm with a picture.

From that information we can determine if using a logic gate or a comparator makes sense. If a comparator is best suited, the tlv3201 should be looked at first. If that’s not fast enough, the tlv3501 would certainly work. But let’s hold off on going down this path until you attach a waveform.

Chuck

Hi Clemens

I will try simulating TLV3201 and share the result.

Regards
Nitesh

• In reply to Chuck Sins:

Hi Chuck

Can you please check and suggest me if i can go with TLV3201

Regards

nitesh

• In reply to Nitesh Kumar74:

Nitesh

this waveform is a bit faster, more like 40MHz, so you will need to go with the TLV3501.  The propagation delay of the TLV3501 is less than 10ns, so this will be required to handle this higher frequency.  The TLV3201 has a prop delay of 40ns, so I can't recommend that device for this higher speed.

Chuck

• In reply to Chuck Sins:

Hi Chuck

I have simulated the same with TLV3501 .But i am not able to get the I/P waveform with 0.8V Pk to Pk.

In my waveform you can see that i have set VIN as 0.8V but waveform is reflecting as 2V.

Can you please check my simulation result let me know what is to be updated.

BR/Nitesh

• In reply to Nitesh Kumar74:

Thanks,
Jonny
• In reply to Jonathan Nguyen:

Hi Jonny

PFA simulation file here.

Regards

NiteshTLV3501.TSC

• In reply to Nitesh Kumar74:

Nitesh,

It seems that you actually adjusted the DC offset value of the input waveform, not the amplitude. To fix your Vin to be 800mV:

1. Double click on VIN
2. Adjust DC Level [V] to 0V
3. Click "Sine Wave" and the "..." button next to it
4. Change the amplitude to 400m to set 0.8V pk-pk