Need help making LED driver unit v. automotive

[kyazh]

Hello folks, thanks for taking your time to read this. I know there are various ready made LED drivers out there, but that just doesn't suit my needs. I am designing custom automotive accent lights and I need to integrade the LED DRIVER unit into the PCB design. What I have been using in the past is a 12V postive fixed regulater supported by a 50V 1oonF and a 25v 1micoF capacitors. The led's themselves where grouped in a series of 3's plus a matching resistor. I would like to further improve this design because automotive voltage is very dirty. My design thus far has been working great, but I would like to know if I can improve it. Thank you.

the unit supports 500ma. These are for 3mm and SMT LEDs, btw

 

[frenzee]

You need to give us a little more info:

What is the Vf of tfhe LED or LED assembly
If an assembly, how iis it wired? Series, parrallel, matrix?
What is the current draw for each individual emitter?
Do you have size limitations for the PCB?
Will the PCB be heatsinked?
Is this for continuous operation or blinking?
Is low cost the main priority or performance?

 

[rgbphil]

One important thing to do for automotive or in fact any long line driven app is to include transient protection. The automotive supply will have all sorts of little lightning bolts surging through it.
Preferably transorbs or varistors (slightly cheaper) should be the first thing added, well grounded and placed before any other components.

 

[kyazh]

You need to give us a little more info:

What is the Vf of tfhe LED or LED assembly
If an assembly, how iis it wired? Series, parrallel, matrix?
What is the current draw for each individual emitter?
Do you have size limitations for the PCB?
Will the PCB be heatsinked?
Is this for continuous operation or blinking?
Is low cost the main priority or performance?

Vf of each led ranges from 2-3.5 volts. The Red and Orange LED's are usually 2-2.4v , the Green, White, Blue's are 3-3.5V. The LED's are in a combination of parallel and series. For example, 3 Amber LED's and a 330ohm resistor on a 12v source. And there could be up to 6 of these. Total current used should be less than 1A for the whole device. I'm not using and high power LED's yet. Each LED draws about 20mA. Size limitations, yes, the smaller the better, whatever will handle up to about 500mA will do in the smallest package available. Continuous operation and blinking. Low cost would be great, but performance is good to, so something that balances in the middle. Thanks!