voltage controlled current source

Thread Starter

mindbomb

Joined Mar 14, 2009
4
Hi

What is the simplest and best way to design a 0 to 5V voltage controlled current source for a stable 0 to 400mA output on low pure resistance loads (<5 ohm)?

Thanks
 

Ron H

Joined Apr 14, 2005
7,063
Hi

What is the simplest and best way to design a 0 to 5V voltage controlled current source for a stable 0 to 400mA output on low pure resistance loads (<5 ohm)?

Thanks
Does the load have to be grounded?
What supply voltages do you have available?
How accurate does the voltage-to-current transformation need to be (%)?
 

Thread Starter

mindbomb

Joined Mar 14, 2009
4
Does the load have to be grounded?
What supply voltages do you have available?
How accurate does the voltage-to-current transformation need to be (%)?
Yep, I think the load has to be grounded, but I will be double-checking this tomorrow. I have a 5V supply available, and the transformation needs to be with 1mA precision at the output..

any ideas?

thanks!
 

thatoneguy

Joined Feb 19, 2009
6,359
This IC Shows schematics for using a precision voltage source as a precision current source or current sink. Output is only 110mA using the the precision voltage source, but other op-amps/transistors could be used as mentioned above.
 

Thread Starter

mindbomb

Joined Mar 14, 2009
4
first- thanks!
second -
should I combine (cascade) 4 of these to achieve maximal 400mA output or just change the transistor/resistor combination to a more wattage capable selection to achieve my target?
 

Thread Starter

mindbomb

Joined Mar 14, 2009
4
third - also for achieving a 1mA precision I will probably need to combine another low output current, high precision unit in parallel (since these units using maxim DS4303 have a minimum 10mA output)
 
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