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Reference for a High Speed voltage follower with input/output between 0 and 4.096V...

Other Parts Discussed in Thread: BUF602, LMH6559

Hi,

I'm desesperately searching for an amplifier to make an input impedance adapter.

My input signal is a DC to 200MHz sinusoidal voltage between 0 and 4.096V with an impedance of up to 1KOhm.

I would like to make a voltage follower but haven't found any reference that could sustain this frequency with this output voltage.

I would like to power my amplifier between +/- 5V or +6V/-5V.

My output load will have about 250 Ohm impedance.

Can you suggest me a reference or a typical circuit that could make my adaptation?

Thanks in advance,

Best regards,

Vincent DECAUX

  • Hi Vincent,

    You may want to take a look at the BUF602 or the LMH6559 for your application. Both these voltage follower devices should be able to support the DC to 200MHz sinusoidal signals with 0 to 4.096V output swing. If you look at Figure 1 in BUF602 datasheet, it can achieve Vo = 5Vpp with large signal BW of 880MHz.

    For the supplies, I would recommend using +6V/-5V as you might run into input and output headroom issues using the +/-5V supplies. The other thing is that for 0 to 4.096V signal swing, you really don't need the negative supply to be so low as -5V because the signal swing is all above GND or 0V. It is possible to make the negative supply as -2V, and the circuit should still support your application. However, I can totally understand that you only have +6V/-5V supplies and supply regulation is not an option.

    Best Regards,
    Rohit