Hi, I am trying to buy a DIP or Through hole current sinks for testing my circuit. I searched Digikey for current source/sink but it is giving me a SOP part specification. Please let me know, where I can buy current source/sink discrete component for cheap. I only need 4 -5 parts max.

Thanks and Best Regards
Shan

 

What is the maximum value of current you wish to sink?

hgmjr

 

Oh, I apologize about the specification. I want a part which can source/sink from 1 mA (max) to 100s of nano Amps. I am not sure if it is possible to get such dynamic range in a DIP or Through Hole but I would still try. Also something between 100s of Micro amp to 100s of nano amp is also good.

thanks

 

So you are looking for something to cover the range of 100 nanoamps on the low side up to a maximum of 1 milliamp. Right?

hgmjr

 

yes that is correct. I am looking 100s of nanoamps on low side to 10s of milliamp on high side. But it can be from 100s of nanoamps on low side to 100s of microamps on high side.

 

So according to the last post any IC with an open collector/open drain output should meet the requirement. If that is true, then any NPN transistor switch should also do the job. In such cases the actual output current is controlled by the load as long as there is sufficient base current to saturate the device.

At current levels of 100 nA to 1 mA you could also use comparators and opamps.

 

Hey Shantanu,

Why dont you build your own current source/sink from discrete parts? That way you can control the current. Also it would be cheaper to build your own than to buy an IC that does it for you. A simple opamp and transistor ought to do it. If you google search the terms "current source tutorial" you should get plenty of ideas.
Best regards
Anand