> elec > appareils-de-mesure > what-s-all-this-femtoampere-stuff-anyhow-andyaronsonnsc

What's All This Femtoampere Stuff, Anyhow?

andyaronsonnsc - 2007-08-30

This show is part of an on-going series from National Semiconductor. The seriesis called "Analog by Design Show - Hosted by Bob Pease". This is show 10. The Analog by Design Show - Hosted by Bob Pease is aimed at analog and digital integrated circuit designers and engineers. Various technologies from National Semiconductor and their partners are usefully described in an educational and entertaining atmosphere.

Analogplanet96 - 2019-12-03

Absolutely Love these videos and Bob Pease, but I'm skeptical about detecting individual cosmic rays with a charge amp. I've played with femto-amp parts like LMP7721 in various well guarded and shielded situations and never noticed even the slightest susceptibility to radiation, except for the low frequency "ion chamber" leakage effect due to intense fluxes from radioactive sources. Would be cool though....

jonahansen - 2010-06-18

"We never saw any really bad parts" - ha ha.

wither8 - 2016-06-23

".01ua is 10 picoamperes right?!?!' '.01 is 10 Nano.Amps.' bob you were an IC beast with the patience of a saint, i would have gone widlar on that idiot.

Harjit Singh - 2016-06-25

The production site was in Malacca MALAYSIA not Indonesia..I implemented this solution into production back in the 90s

Andrew - 2011-10-24

RIP bob

Michael Molter - 2015-10-13

13:09 is where the actual discussion starts.

definition of is - 2011-06-22

I heard here, Bob Pease died in a car crash: theamphour com/2011/06/20/the-amp-hour-48-posthumous-pease-porridge/

boB Gudgel - 2018-03-27

Yes, unfortunately. And I think it was returning from his friend, Jim William's funeral. Another great designer

Gerry James Edwards - 2018-04-12

Yes, such a sad coincidence. We had to say goodbye to two of the giants of analog electronics in the space of a few days.

Gerry James Edwards - 2018-04-12

I bet you could have learned a hell of a lot, as well as had a good laugh, if you could have earwigged on Bob and Jim shooting the breeze.

Gazza-in-the-usa - 2021-01-30

@boB Gudgel Yes, he was returning from Jim Williams Wake at Mountain Winery in Saratoga, CA from what I recall. I knew a few guys who were there at the wake.

Kelvin Le - 2015-10-24

does anyone notice how the op amp low pass filter at 2:05 is drawn incorrectly. Look at the positive and negative terminals.

Faidul islam sheikh ফাইদুল ইসলাম শেখ - 2018-12-14

You are wrong

boB Gudgel - 2021-01-30

Yep it sure is. Wrong input polarity that's not going to be too good of an amplifier buffer

Zane Victor Kaminski - 2017-05-22

I enjoyed the Agilent plug. I would love a 54642D scope, but they're still a bit pricey (~$1000 USD) and they only have two analog channels. My friend picked up a lower-end 54622D for $100, which has the same user interface but only samples at 200 MSa/s, which isn't fast enough for all of my work.
The newer MSO6000 series has four channels and greater bandwidth and sample rate, but they have kept their value very well and are even further out of my budget, at $5000+ for a model with fair specs.

Humgar LLC - 2019-03-02

I love the 54600 series. The design is very intuitive and it's usually problem free. 54640 series is a different beast that has a quirk that the ADC runs too hot and the hybrid will eventually fail if there is not a custom fan blowing at it directly. It's worth around $3.8k so if you can get it at $1k, it's a steal. Chances are recyclers are willing to sell it to you at that price but you are on your own once the 30 or 60 days is over. You can do the fan mod yourself with the instructions here: https://wonghoi.humgar.com/blog/2016/07/24/agilent-54641d-fan-mod/

advanced microsystems - 2020-04-20

@Humgar LLC just picked up an 54642D with complete probes and SMD clips for 350€.
3.8k is a joke...I mean Keysight official Ebay shop will sell you a 1Ghz 4ch 3000X for around 6k, so charging more than half of that for a 20 year old unit with just 2 ch and CRT is ridiculous.

MN M - 2018-01-30

who needs a cosmic ray detector?