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I have a square wave, to which I have to add a buffer. The Frequency of the square wave is around 10MHz. I am new to Op-Amps, but I have read that I need a high slew rate.

Can I use any Op-Amp(with a high slew rate) as my buffer?

Thanks in advance.

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  • \$\begingroup\$ Is your square wave of variable amplitude or rail-to-rail? \$\endgroup\$ – skvery Mar 6 '17 at 18:55
  • \$\begingroup\$ what do you need of that square wave? is actual amplitude relevant, or is it actually "the higher, the steeper, the better"? \$\endgroup\$ – Marcus Müller Mar 6 '17 at 18:57
  • \$\begingroup\$ The Square wave is of fixed amplitude. It is generated by a rpm sensor, its frequency is important. \$\endgroup\$ – Udayan Joshi Mar 6 '17 at 19:39
  • \$\begingroup\$ What is the source impedance? Mainly, op amps connected as buffers lower the source impedance, but you might want voltage gain as well. \$\endgroup\$ – Whit3rd Mar 7 '17 at 10:53
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No. A voltage follower is a unity-gain amplifier, and not all op-amps are stable in unity gain configuration.

You need to specifically choose an op-amp that is "unity-gain stable".

Of course you also need to find an op-amp with the required slew rate; able to produce the output current needed by your load; able to work with the power supplies available; able to produce the required voltage swing when using those power supply voltages; etc.

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  • \$\begingroup\$ Can you use an Emitter Follower? \$\endgroup\$ – analogsystemsrf Mar 7 '17 at 4:09
  • \$\begingroup\$ Is there anything else than an op-amp that can be used here? \$\endgroup\$ – Udayan Joshi Mar 8 '17 at 19:27
  • \$\begingroup\$ @UdayanJoshi, If you're just interested in buffering a square wave and preserving its frequency (but not saving any information about its amplitude), then you can use a digital buffer. Which one and how to connect it depends on the details of the source and the square wave signal. \$\endgroup\$ – The Photon Mar 22 '17 at 15:07

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