Other Parts Discussed in Thread: TLC59116
Tool/software:
Heya there,
I have recently had a PCB made to test out the TLC59116 with some LED's, including pushing it up to max power (120mA current per channel) to try and push 2000 lumens with my selected 16 LED's connected to the TLC59116.
Having set REXT to the appropriate value to sink 120mA per channel, I can confirm that I am able to sink 120mA through just one LED on any channel, but as soon as I start turning on more channels on the controller, instead of seeing n*120mA being drawn at my power supply, the more LED's I turn on, the lower the current per LED, at full tilt I only managed to draw a total of 800mA on my supply, meaning only 50mA per channel, which is more than a 50% drop so not that negligible.
The LED's I am using are the Cree JB3030CWT-F-H50EA0000-NZ000001 and I have a supply voltage of 3.3V.
I tried to push the supply up to 5V but with little return, I cant remember the number but I don't think I managed to push anything over 1A total so 63mA per ch.
My lab power supply is capable of delivering up to 3.2A so not a limitation on that side, and I even tried building a linear regulator with a large capacitor bank but with no improvement.
This is my first time messing with such LED driver chips, so either I have completely misunderstood the datasheet, or something more subtle is going on here, I appreciate any potential insights as to why I am not hitting the 120mA/ch current with all LED's on.
Best Regards
Hector
