TIOL111: How to calculate resistance value for Current limit?

first_name Chavez

Part Number: TIOL111

The datasheet doesn't specify a formula to calculate the resistance value needed to limit the current of pin ILIM_ADJ. How can I figure out the resistance for this pin?

over 7 years ago

0 Miguel Robertson over 7 years ago

TI__Guru 62920 points

Hello,

You can reference Figure 4 in the datasheet to see the relationship between RSET and the output current limit.

Max

0 first_name Chavez over 7 years ago in reply to Miguel Robertson

Prodigy 20 points

Thanks for the info, do you have any specific value that works for 200 mA (since an IO-Link master can only have an output of 200 mA). I could interpolate the graph but if from previous tests you already have a working value that'd be great.

Thanks in advanced.

0 Miguel Robertson over 7 years ago in reply to first_name Chavez

TI__Guru 62920 points

Unfortunately not, since when we checked this we tended to do it the opposite way - i.e., incremented through resistance values and measured the overcurrent threshold. At 10 kOhm the limit was above 200 mA and at 20 kOhm it was below, so interpolation is the way to go to figure out how to get to 200 mA. It looks like 15 kOhm would be the standard resistor value that would make the most sense.

Max

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TIOL111: How to calculate resistance value for Current limit?