Hello,
I am looking for a 1 mAmp DC current source circuit design with 0.02% precision to be used in a 5V power supply circuit board and a 3KOhms load.
Any suggestion/direction would be helpfull.
Thank you all.

 

Is the 3kΩ load grounded?
Is 0.02% also the accuracy you need? Why so precise?
What is the ambient temperature over which this accuracy is required?

 

And in addition to Wally's questions - do you have access to a 0.002% accurate resistor, voltage reference device, or both? Or an accurate meter to trim a very stable but off-value component?

ak

 

It can be done, what’s your budget? I would like to know the full requirements including temp range and application

 

Thank you all for your replies and feed back.
The measurement will be used in reflection but will also be used in other applications from -30 ° C to room temperature.
These apps might not need that level of precision, but I want to find the most accurate current source that I can get with my resources.
I can have access to a 0.01% resistor and a 0.02% voltage reference.
The current will be measured using a current sense resistor coupled to an Inst. Amplifier connected to an ADC.
The load is grounded.

 

Please read : The measurement will be used in a reflow owen.

 

The current will be measured using a current sense resistor coupled to an Inst. Amplifier connected to an ADC.

What is the precision (no. bits) of the ADC?
For 0.02% you will need at least 16 bits.

 

Yes, i am using a 16 bits ADC

 

Hello,
Any idea or suggestions ?