Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

led driver circuit ideas

Status
Not open for further replies.
G

gungor

Newbie level 2
Joined
Mar 27, 2008
Messages
2
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Turkey
Activity points
1,294
Hi All,

I have a 5V input. I need a circuit to drive 40 LEDs connected in parallel. Maximum current will be 800 mA (20 mA/LED). LEDs will open at 2.4 V and maximum brightness is at 5V. It is needed to control brightness in maximum 32 steps.

So I need a converter with a 5V input, having output variable between 2.4 to 5V in maximum 32 steps.

I have thought of:

Putting a mosfet between 5V and anode of leds and driving gate by pwm.

My question is:
Is this a feasible approach? What are the critical things for this implementation?
Do you have other suggestions?
Thanks in advance.
Regards, Gungor
 

use 6.8R risestance in series to flow of current limt to maxmum 800mA
 

Hello gungor

In order to comment,what is Vf of LEDs. Actually no single LED's Vf can bear 5V.

Good Luck.
 
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top