How to design a 10nA DC current source?

[Bus Master]

Hi there,

I need to design a 10nA DC current source, stable DC output.

Anybody can help?


Thanks in advance.

Yours,

 

[bomba]

do you need the load referenced to gorund???? If not you can uses this attached circuit

 

[bomba]

I posted a similar topic few weeks ago.
You can find answers at your question
**broken link removed**

 

[flatulent]

leakage

At these low currents, leakage of components and board surfaces are a major factor. The other problem is measuring your circuit to make sure it works. One way would be a 1 M ohm resistor which would produce a 10 mV drop. Be sure to use a modern meter with 100 M ohm input impeance.

The input bias current of the op amp will disturb the circuit. So will transistor circuits with Ico currents.

 

[Humungus]

The solution used in CMOS is to implement a beta multiplier biased in weak inversion. I made one of this fro biasing a pacemaker circuit. There is no problem to get this currents provided that the temperature range is not so wide, as current is proportional to Vt

 

[artem]

Hello guys .
I have just made circuit . But can not prove whether it will work or not .
It uses normal OpAMp and works to the ground (should work ). But
it needs some startup circuit . Working load is Load resistor.
The current is defined by zener diod and R1 diod .

The file is in Circuit Maker format