Current Mode Regulator IC

[Harrkev]

Hi. Sorry if this is old news....

Linear makes a current-mode regulator chip designed to drive white LEDs. The textbook application requires only one resistor, one inductor, and two caps, and one diode (besides the white LEDs) in order to work. It claims up to 80% efficiency. The datasheet lists applications for one-cell and two-cell circuts with varying numbers of LEDs. It even shows a 10-led circuit! You can control the output current with a resistor, or even use PWM to control the brightness (555 + op-amp anybody?).

Linear LT1932
www.linear.com/go/dnLT1932

 

[Go Go Gadget Flashlight]

May be old news, but if it is, I missed it before. Looks real good, but I didn't find any eval boards or pricing...

Still looking, have to check again later.

Nice find (assuming it is "new" news).

 

[jeff1500]

I looked at it. It's a great chip in a very small package. I've always wondered how they hook them up to circuit boards. I have a couple of free samples from Maxim for a similar chip. They're about the size of a lady bug.

 

[Silviron]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Go, Go Gadget Flashlight:
May be old news, but if it is, I missed it before. Looks real good, but I didn't find any eval boards or pricing...
<HR></BLOCKQUOTE>

Yeah, I havent seen it either. Price is $2.07 for quantities of 1-100
Click on the "Buy Now" button at the top corner of the datasheet online: http://www.linear.com/prod/buy.html?datasheet=771&product_family=power

Seems pretty inexpensive to me - the other components will probably cost more !

Looks useful- Too bad there arent eval boards, but they look simpler than the NS-2621 etc, so the eval board may not be as important.

 

[Harrkev]

Seems like a nice chip, but I pity the poor sap who tries to solder the thing. I have managed to screw up soldering surface-mount devices before.

Since this device switches at over 1MHz, the board layout will be critical. This is probably not the type of thing that you could breadboard (at least with any type of efficiency).