OPA690: OPA690 power design

Eric Shen42

Part Number: OPA690

Hi Team:
My customer use OPA690 and wants to do the application of active filters. The input signal is negative pulse signal with the range of -10mV to -1V. Please help confirm its power supply mode, Is ± 2.5V or ±5V appropriate?

Thanks!

Regards!

Thanks!

over 4 years ago

0 Jacob Freet over 4 years ago

TI__Expert 7875 points

Hi,

Does the customer want any gain on the filter design? The required power supply will depend on how much output voltage swing they need.

Regards,

0 Eric Shen42 over 4 years ago in reply to Jacob Freet

Expert 2750 points

Hi Jacob:

Thanks for your replay!

If no gain requirement, is ± 2.5V or ±5V appropriate? If gain is 4, Is ±5V appropriate?

My customer wants to do 150MHz low-pass filter. Does OPA690 make sense? Can you give me a reference design？

Thanks!

Regards!

Eric Shen

0 Michael Steffes over 4 years ago in reply to Eric Shen42

Guru 47535 points

You can't do an active filter at 150MHz,you should do a passive filter and buffer it with the OPA690- at gain of 4 will be too slow to pass 150Mhz.

0 Michael Steffes over 4 years ago in reply to Michael Steffes

Guru 47535 points

Incidentally, if you absolutely had to do an active MFB filter at 150MHz (butterworth), you would need a minimum of 2.6GHz gain bandwidth product if you were to target a min. loop gain of 20dB at the noise gain peak.

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OPA690: OPA690 power design