Using trim-pot in small batch production

Community PCB Design
1

Hey all,

I’m looking to design a small (semi)hobbyist board. Part of my design calls for a series of indicator LEDs. I plan on using a TI TLC5925 constant-current LED driver. It calls for a current set resistor, and I’d like to put a resistor and trim-pot in series to set a minimum R, but allow for user adjustment to set LED brightness as desired.

My question is, what can you expect in terms of the “default” value for a trim-pot to come from the factory as? If I ordered a bunch of 5K linear taper trimmer, should I expect them to all come set at 5K, all set to 2.5K, all set to 0, or some random distribution of values?

Thanks!

2

I would expect them to come at random, but with enough money, you could have whatever you want.

3

Alrighty. Thanks! I was really hoping they’d come at one extreme or another.

4

Why does it matter?

As part of the assembly simply set them midpoint or even to the correct value during test.

Make your design so that if they are set to either extreme the circuit still works OK.