EEVblog 1755 – Tolicore Femtoammeter TEARDOWN + REVERSE ENGINEER

Demo, teardown and reverse engineering of the Tolicore 3720 Femtoammeter and voltage source.
https://tolicore.com/products/3720-femtoammeter-voltage-source/
https://tolicore.com/product-documents/3720-Datasheet.pdf
Keithley low current measurement handbook: https://www.tek.com/en/documents/product-article/keithley-low-level-measurements-handbook—7th-edition
Counting LED photons video: https://www.youtube.com/watch?v=TJcMgoJ4DOE

00:00 – Femtoammeter measurement
01:16 – Tolicore 3720 Femtoammeter unboxing
03:39 – Power on and UI
05:18 – 20pA full scale range
10:13 – Bluetooth and
11:35 – Humidity measurement is important
12:21 – Crazy sensitive!
13:45 – LED as a current source demo
15:28 – 1nA measurement test
16:43 – Burden voltage and electrometer input + self calibration
20:14 – Teardown
22:20 – Voiding the warranty
25:05 – Reverse engineering
27:32 – How a PCB guard ring works
33:52 – Humidity matters
34:33 – The voltage output
35:23 – Porcelain Multilayer Capacitors
36:22 – Voltmeter input
38:24 – Potentiostatic and Amperostatic Coulometry
40:15 – ADA4530-1 Internal schematic
42:25 – Contamination and PCB assembly cleaning matters
44:03 – Rogers PCB material

Forum: https://www.eevblog.com/forum/blog/eevblog-1755-tolicore-femtoammeter-teardown-reverse-engineer/