LT3081
Recommended for New Designs
The LT3081 is a 1.5A low dropout linear regulator designed for rugged industrial applications. Key features of the IC are the extended safe operating area...
Datasheet
LT3081 on Analog.com
LT3091
Recommended for New Designs
The LT3091 is a 1.5A, low dropout negative linear regulator that is easily paralleled to increase output current or spread heat on surface mounted boards...
Datasheet
LT3091 on Analog.com
Hi,
I'm trying to figure out how to program the external current limit for multiple LT3091/LT3081 connected in parallel.
From the LT3091* datasheet I can see that it is possible to use a single common resistor to program the current limit of all the regulators. However, I am unsure how to modify the R_ILIM equation to account for multiple LT3091* in parallel. Any help you can provide would be greatly appreciated.
For the LT3081*, it appears that each regulator should have its own R_ILIM resistor. With a programming scale factor of 20 kOhm A, each LT3081 will need a 20 * N / I_LIMIT kOhm resistor (with I_LIMIT being the total maximum current and N the number of regulators). Is this right? Would it be possible to use a single common resistor to program the current limit of all regulators also for the LT3081*?
Thanks. Best regards,
Andrea
(*) As pointed out by ARad, I have swapped the part numbers of the two regulators.
Hi. As far as I can tell, the LT3081 datasheet has a reference design with the ILIMs connected and the LT3091 datasheet does not. That is the opposite of your text. I show how I would calculate RILIM for LT3081s in parallel in one of the images below. LTspice is a little off, but that may be intentional since that is true even for a single LT3081.
