I’m looking for some sort of integrated circuit that could be used to read the i/v curve of a diode. Is there a single integrated circuit for something like this? Or do I need to go with a dedicated DAC, ADC and precision resistors? I can implement the control of the voltage and current on a micro controller, but since I am space constrained I would ideally not have the extra components in this specific design
Greetings,
I’m not aware of a purpose-specific IC for such a task–it seems a bit specific/narrow to support a mass-market product, but I’ve been surprised on occasion.
Defining your measurement objectives/requirements would be important here: it’s one thing to measure to 8-bit resolution versus 18-bit resolution, and another thing again if one wants accuracy on top of that. Different yet again if one wants to take a few milliseconds to do it versus do it a few million times a second. And so on…
If you have an MCU with mixed-signal peripherals good enough to make the necessary measurements, great. If not, you’ll need something external that is suitable, for the same reasons that one can’t really measure microns with a meter stick.
The circuit below is one idea that comes to mind offhand as a possibly useful starting point. Basic idea is that the measurement point can be adjusted using a relatively cheap DAC buffered by U1, while a better ADC takes 2 measurements to sample the voltage across the diode and current as appears across R3.
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Thanks! after looking for a while I found these:
Which should work for the task at hand with only 1 external resistor per channel.