New 350mA driver, V useful · AditNow Community

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royfellows
50.2% (Neutral)
Newbie Topic Starter

10 years ago

Hi fellow bat burners
Just bumped into this on Farnell
http://uk.farnell.com/on-semiconductor/nsi50150adt4g/led-driver-pwm-50v-to-252-3/dp/2382343

A 350 mA driver based on self biased transistor technology from ON Semiconductor, the same people who brought us the 25mA and 30mA. jobbies. Only 3 solder points and no external components except an adjustment resistor, and possibly a reverse polarity protection, Schottky or MOSFET
Can be paralleled to give 350mA X number, or used to drive LEDs in series or whatever.
22p plus VAT.

Usefulness is that is can do same job as 7135s but at higher voltages, up to 50V, and used to drive LEDs in series.

If anyone has opinions, please lets hear them.

My avatar is a poor likeness.

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Mr Mike
50.2% (Neutral)
Newbie

10 years ago

A nice find Roy. However that one is only the 150mA version. Farnell do not sell the 350mA one at the moment.

On Semi do a whole series of linear LED drivers, including a 1A one as well. The CAT4101 is a little more sophisticated, but still very simple to implement. See:

http://uk.farnell.com/on-semiconductor/cat4101tv-t75/ic-led-driver-to263-5/dp/2102570

Mr Mike www.mineexplorer.org.uk

royfellows
50.2% (Neutral)
Newbie Topic Starter

10 years ago

Unless I miss something its 350mA if R adj = about 6 ohms?

Data sheet requires quite a bit of study as I have been scratching my head over it for about 10 minutes
:lol:

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ChrisJC
50.2% (Neutral)
Newbie

10 years ago

Is it not just a Current Mirror?
http://en.wikipedia.org/wiki/Current_mirror
(albeit in a single package with probably a few tweaks).

What it doesn't do is work efficiently. If your battery voltage was twice that required by the LEDs, then half of your power would be being dissipated in this device (note the large heatsinking area). Not too clever for battery life.

Chris.

royfellows
50.2% (Neutral)
Newbie Topic Starter

10 years ago

At the 3 terminal (R adj) open default of 150mA running a Lynx pilot off one of my 7.8V 5200 mAh power packs!

You aught to be on the stage Chris
:lol:

Joking aside I will run some tests just to see, but I fancy that efficiency will fall as input voltage overhead increases. I want the 350mA capability for something else I'm building
;)

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sinker
50.2% (Neutral)
Newbie

10 years ago

"Mr Mike" wrote:

On Semi do a whole series....

Hahahahaha I so want to work for a company called "On Semi"!! hahahahah :lol: :lol: :lol: :lol: :lol:

Yma O Hyd....

lozz
50.2% (Neutral)
Newbie

10 years ago

The Max reverse voltage for that device looks very low if I'm reading the specs correctly.

Lozz.

royfellows
50.2% (Neutral)
Newbie Topic Starter

10 years ago

Some day I will get one of the people who actually understand the data sheets to explain one to me!
:lol:

At least not written in Chinese

Anyway, opened a new thread on the 'The Project'

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royfellows
50.2% (Neutral)
Newbie Topic Starter

10 years ago

Well here it is now they arrive from Farnell.

🔗Personal-Album-128-Image-97503[linkphoto]Personal-Album-128-Image-97503[/linkphoto][/link]

Easy to work with and solder but large heat sink area tells a story, as Chris pointed out. Thing is, all these linear drivers have current out equal to current in, so its the voltage overhead thats converted to heat. Potentially very inefficient, but efficiecy is related to voltage overhead which is defined by LED configuration.

I see useful applications for someone doing a simple lamp build or Oldham conversion using single LED at low voltage, but pondering the data sheet and playing around with them little use to me.

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lozz
50.2% (Neutral)
Newbie

10 years ago

#10

Unless it's not dropping a lot then there will usually be a decent chunk of power dissipated in that type of device, lot's of more efficient switchers around these days.

Lozz.

royfellows
50.2% (Neutral)
Newbie Topic Starter

10 years ago

#11

Aware, hence my final comment.
;D

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