anyone familiar with IC LED drivers?

[archer6817j]

I was cruising around on www.newark.com and found several LED drivers as "recommended" products. I also don't know much about electronics so I was wondering if anyone had input on whether these types of drivers were usable/any good.

I realize the ones I linked to may not be "exactly" the right ones, but I'm wondering about the general type of driver. The specs on the second driver list "flashlights" under possible applications. So, whats the deal?

This particular one is (is this possible?) 2mm x 2mm

Features

TEXAS INSTRUMENTS - TPS61160ADRVT - IC, WHITE LED DRIVER, BOOST, SON-6

700mA
2.7V to 18V Input Voltage Range
26V Open LED Protection for 6 LEDs (TPS61160A)
38V Open LED Protection for 10 LEDs (TPS61161A)
200mV Reference Voltage With ±2% Accuracy
PWM Interface for Brightness Control
Built-in Soft Start
Up to 90% Efficiency
2mm × 2mm × 0.8mm 6-pin QFN Package With Thermal Pad

Or this one: NATIONAL SEMICONDUCTOR - LM3405AXMK/NOPB - IC LED DRIVER CONST CURRENT/BUCK TSOT236

Description

IC LED DRIVER CONST CURRENT/BUCK TSOT236
Device Type:LED
Topology:Buck (Step Down)
Input Voltage Range:3V to 22V
Output Voltage:20V
Output Current:1A
No. of Outputs:1

 

[Toke]

The idea is that those small 6 legged buggers are placed on a small print with other small components.

The first can vary the current and thereby brightness.

The second is set for 1A, but can pulse the diode on and off to give an effectice change in brightness.

They have slightly different applications but both require a lot of knowledge of electronics to build a driver print around.

 

[archer6817j]

Sorry for my ignorance but what is a "driver print?"

So does that mean you can't (with very tiny gnome hands) solder directly to the leads?

 

[Toke]

Sorry for my ignorance but what is a "driver print?"

If you dismandle your flashlight you will see a small circular printcard inside.

So does that mean you can't (with very tiny gnome hands) solder directly to the leads?

No, read the datasheet for the components, they require several external components to function. Those have to be fittet on a small printcard.

 

[DIWdiver]

I was cruising around on www.newark.com and found several LED drivers as "recommended" products. I also don't know much about electronics so I was wondering if anyone had input on whether these types of drivers were usable/any good.

I realize the ones I linked to may not be "exactly" the right ones, but I'm wondering about the general type of driver. The specs on the second driver list "flashlights" under possible applications. So, whats the deal?

This particular one is (is this possible?) 2mm x 2mm

As an electrical engineer who has designed numerous LED driver circuits both professionally and as a hobbyist, I think I can fill you in on "what's the deal?"

Yes, it's possible those sizes are accurate. However, that's not the whole driver. As Toke said, you need numerous other parts along with either of those ICs. Several of those parts will probably be bigger than the IC.

It is actually possible to solder to the leads on the IC, even with my distinctly non-gnomish hands. It requires good skills, good tools, and extraordinary patience. And when you're done, it's a lousy way to build a light, as it's very unreliable. It's really only practical for building or modifying a prototype, so you know how to build the next version of your circuit board (aka printed circuit board, PCB, print, printcard, board, etc), where you will only have to solder the parts to the PCB. Whatever you do, you will need something to mount all the parts on, and a PCB is by far the most common thing to use.

Unless you have the desire to read and understand the data sheet, select components, design and assemble a PCB, test, and start over at least once and probably more, I don't recommend attempting this. Unless, of course, you already have these skills.

Fortunately there is a better way. You can buy a driver board from someone who has already done all this work for you. You can read reviews and/or recommendations by others here on CPF. A lot of CPFers buy boards at DealExtreme.com (often referred to as DX). You can buy completed boards there cheaper than you can buy the parts.

Also, while I don't remember the exact location, there's a list on the forum of quite a few different driver boards, many of them made and sold by CPF members. It includes descriptions and lots of helpful information.

D