Multiple CAT4101's to drive a SST 90?

BlitzkriegSSII

Newly Enlightened
Joined
Dec 9, 2013
Messages
2
Im wanting to make a work bench light using a SST 90 (flux bin N3) that I have. I'm thinking of machining a reflector and mounting the chip to a large CPU heat sink. I'm looking more for a flood light then spot. I was going to use the 5 volt side of an old computer power supply to power the driver.

Im looking at running 9 of the CAT4101s in parallel to provide up to the 9 amps of power. I was thinking I should be able to use a variable resistor on the RSET pin to fade the LED instead of adding the cost of PWM to the driver. Does anyone have any experience doing this?

What I have done before for the CAT4101's is machine out a base to clamp them down in and then just solder what I need to the pins. The aluminum base also acts as a nice heat sink for the drivers. Has anyone else used this many CAT4101's in parallel?

Looks like I can get everything I need for about $30 to make the driver, is there a cheaper driver out there that will power that LED the way I want?

I have some Cree XP-g's that I'm using 2 of the CAT4101's in parallel with an arduino running PWM that have been working great that is the reason I'm looking at them to make the driver.

Thanks in advance for your help!
 

Steve K

Flashlight Enthusiast
Joined
Jun 10, 2002
Messages
2,786
Location
Peoria, IL
As a general rule, I'd rather see a single regulator used instead of running nine in parallel. I can't think of anything rated for 9A, though.

The only suggestion I'd make right now is to have the heatsink tied to the ground. I'm assuming that you'll have the tabs mechanically connected to the heatsink, and the tab and heatsink will be electrically connected as a result. The datasheet says: "For best thermal performance, the tab should be soldered to the PCB and connected to the ground plane".
As always, you'll want to review the datasheet carefully and be sure that you understand it.
 

BlitzkriegSSII

Newly Enlightened
Joined
Dec 9, 2013
Messages
2
Thanks for the suggestions! DIWdiver ill keep that in mind, I may one day get around to making a flashlight. Ill let yall know how the light turns out.
 

Mike S

Newly Enlightened
Joined
Apr 29, 2011
Messages
132
It should work just fine, but were you going to use a single pot to control the current?

If you already have experience with arduino and there's a 5V source, I'd use it to program an attiny13 and go that route instead.
 
Top