cheap currents probes for 20pA to 100 uA  - Page 1
Forum section: electronics / testgear

author: billuanand
author_rank: Newbie
timestamp: October 19, 2015, 12:04:18 pm
content: hi,is there any current probes in 20pA to 100 uA current range with 50MHz bandwidth.please advice me low cost current probeand what is the Sensitivity mv/A in current probes, how it relate practicallythank you

author: HighVoltage
author_rank: Super Contributor
timestamp: October 19, 2015, 12:28:27 pm
content: The Keysight N2820A comes to mind but it only goes down to 50uA and is NOT cheap

author: LA7SJA
author_rank: Regular Contributor
timestamp: October 19, 2015, 02:53:51 pm
content: So you want to messure the current from a 3.00 Volt 50 MHz source in a 150 TOhm load? Why? And even more importantly 20pA to 100uA is a 67dB range, linear from DC to 50MHz and of course cheap!The Keysight N2820A has a 3MHz bandwith and it only costs $4,088 the N2821A has a $3,066 price.If you could only tell us what you are trying to messure, it would be more easy to try and help you.Johan-Fredrik

author: billuanand
author_rank: Newbie
timestamp: October 20, 2015, 04:05:26 am
content: i want measure current at gate and drain of FET for current gain measurement. typically current ratings are 20pA to 100uA i want sense this current.

author: BravoV
author_rank: Super Contributor
timestamp: October 20, 2015, 04:06:14 am
content: What is your budget limit ?

author: billuanand
author_rank: Newbie
timestamp: October 20, 2015, 04:18:48 am
content: suitable product as low as possible.and their is any alternative to measure current using DSO, VNA etc. for this measurement

author: BravoV
author_rank: Super Contributor
timestamp: October 20, 2015, 04:26:19 am
content: Quote from: billuanand on October 20, 2015, 04:18:48 am1 ? 10 ? 100 ? 1000 ? .. rupee ?

author: billuanand
author_rank: Newbie
timestamp: October 20, 2015, 05:11:28 am
content: i dnt know about current probes cost, first i want to know is it possible with any product or not.please advice me, i searched lot for current probes but unable to find in this current range.thank you.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 20, 2015, 05:21:53 am
content: Quote from: billuanand on October 20, 2015, 05:11:28 ambecause pA is very rare and highly specialized area... are you in specialized area?

author: billuanand
author_rank: Newbie
timestamp: October 20, 2015, 06:21:58 am
content: yes, i want measure current at gate and drain of FET for current gain measurement. typically gate current is very low.

author: singapol
author_rank: Frequent Contributor
timestamp: October 20, 2015, 08:02:57 am
content: Quote from: billuanand on October 20, 2015, 05:11:28 amHP4140BPicoamp meter and DC voltage source perhaps? Find a cheap working unit or repair it.There are modern version of 4140 but can you afford it?http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.Xhp4140b.TRS0&_nkw=hp4140b&_sacat=0

author: Marco
author_rank: Super Contributor
timestamp: October 20, 2015, 09:55:08 am
content: FETs with current gain, huh?

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 20, 2015, 11:15:58 am
content: he is in "specialized area" allright? he want to measure parasitics, for what is beyond me..

author: Zero999
author_rank: Super Contributor
timestamp: October 21, 2015, 10:10:23 pm
content: Quote from: billuanand on October 19, 2015, 12:04:18 pmThe shot noise at 20pA over a 50MHz bandwidth is 17.9pA so it's not possible to do that with any degree of accuracy.https://en.wikipedia.org/wiki/Shot_noise#Effects_of_interactions