Why don't I need resistors when using an/this LED driver chip?

Thread Starter

EnjoyIce

Joined Jan 13, 2014
25
Hi guys,

I am using an LED driver chip to drive some LEDs ( https://www.adafruit.com/products/1429 ) and it says I do not need any current limiting resistors.

Why is this actually the case? I have been using the chip and the LEDs are fine without resistors but was just wondering how it actually works (what the electronics are behind it!)

Thanks
 

OBW0549

Joined Mar 2, 2015
3,449
Hi guys,

I am using an LED driver chip to drive some LEDs ( https://www.adafruit.com/products/1429 ) and it says I do not need any current limiting resistors.

Why is this actually the case? I have been using the chip and the LEDs are fine without resistors but was just wondering how it actually works (what the electronics are behind it!)
You don't need LED series resistors because the TLC5947 driver IC handles the current limiting for you. The chip data sheet will probably shed some light on the details.
 

dannyf

Joined Sep 13, 2015
2,197
Because you don't have to have a resistor in there. A resistor is just a sample way to stablize the current.

There happens to be other ways to stablize current and the chip is question is an example.
 

TheButtonThief

Joined Feb 26, 2011
237
When you think about it, a series resistor is just a very simple LED driver, a fixed one at that. What you have their still limits the current to each LED, just in a different way.
 
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