Why A Dedicated Noise Analysis for A Strong-arm Latch / Comparator?

[@ajithsrighakollapu3569]

The lecture is really great , please create the separate playlists for PMIC, Mixed-Signal.

[@circuitimage]

Thank you 🙏 so much for the great suggestions. I’ll definitely do that later.

[@abhiruplahiri1]

That's a good refresher.

[@circuitimage]

Thank you so much for the feedback.

[@soumenmohapatra4242]

Nice One. Refreshing.

[@circuitimage]

Thank you 🙏 so much for your feedback. I am glad you enjoyed it.

[@sreenivas2175]

Your explanations and videos are really good and useful. If possible, please share the playlist on analog ic design.

[@circuitimage]

Hi Sree, thank you for your feedback and I'm glad that helped. 😊 I would share the playlist on analog ic design once all the videos are done.

[@ericcartman5396]

Thank you for creating these videos! Could you cover the strong arm offset calibration techniques as well?

[@circuitimage]

Hi Spaceboy, nice to meet you and you're welcome. That's done here.😀

[@bobbylu3490]

There is no perfect solution, only solution of balance

[@circuitimage]

Hi Bobby, thank you for the feedback and you're correct. 😄

[@HaykDingchyan]

Nice job , please add captions as well for better understanding ! 😊

[@circuitimage]

Hi Hayk, nice to meet you and thank you for the reminder. Done. Could you please check if that works for you? 😃

[@HaykDingchyan]

Nice to meet you too! Yep that's working now !

[@circuitimage]

@@HaykDingchyan Great. Thank you for the quick checking and I'm glad that helps.

[@AravindRavichandran-v3n]

I don't understand your conclusion of how increasing the threshold voltage of input pair and lowering the input common mode will decrease noise. It seems counter-intutive. Can you please elaborate on this point?

[@circuitimage]

Hi Aravind, nice to meet you and thank you so much for the feedback. Reducing the overdrive (VCM - VTH) can reduce the noise. Then increasing the threshold voltage (VTH) of the input pair equivalently reduces the overdrive. Also, lowering the input common-mode (VCM) equivalently reduces the overdrive.

[@elilotchen8553]

hello, Dr.chen, why lower the threshold voltage of input pair can decrease the noise of strong arm latch ?

[@circuitimage]

Hi Elilot, nice to meet you and thank you for the great question. Intuitively, the higher threshold voltage would have a less disturbance effect at the input of the sampler; therefore, the input-referred noise would be smaller.

[@arnaud.lancelot]

I m afraid it s the opposite around. One should reduce the capacitance.

[@circuitimage]

Hi @arnaud.lancelot, thanks for the feedback. Could you please elaborate on your concern?

[@arnaud.lancelot]

@@circuitimage If the diff pair acts like an integrator, the gain has the form of gm/C. The input noise is (kt/C) /(gain x gain) . So input noise should look like kTxC/(gm x gm). So boost the gm transconductance for sure but diminish the capacitance C.

[@circuitimage]

@@arnaud.lancelot I agree. So, in my video, I mentioned, the bigger C the less noise, but the speed goes down.

[@arnaud.lancelot]

@@circuitimage What i m saying is that you should look at the SNR, signal to noise ratio. The smaller the capacitance, the lower the noise from... the input perspective. So you increase the SNR at the input. But you also increase it at the output (gmxgmxVxV/CxC)/(kT/C) ~1/C So you reduce C. you go faster and has a better SNR. Reducing the noise is useless if you reduce even more the signal gain.

[@circuitimage]

@@arnaud.lancelot Thanks for the feedback, 🙏 and I agree with your SNR, which should match the input referred noise, which is the ouptut noise/gain, not just noise itself. 🎉😊