Thank you very much... This are really something similar iw as looking for...

If you are going into production TI will be very happy to help so that you can buy thousands of their parts. Likewise other semiconductor companies.

 

If You don't even know the Specs of the LEDs you are using,
how could this possibly be a Commercial-Endeavor ?

Did You buy a ~1000 of them at an Auction ?, and now You want to go into Business ?
.
.
.

 

If You don't even know the Specs of the LEDs you are using,
how could this possibly be a Commercial-Endeavor ?

Did You buy a ~1000 of them at an Auction ?, and now You want to go into Business ?
.
.
.

Sir, right now i am just prototyping the design, so i'm trying to do on what i have (18 watts Panasonic LED panel). If i succeed in this then i can make a proper and my own kind of LED series parallel combination with any smd LED available in wholesale market. But for that i need to prove the financier that i can make one. After that i can modify circuit for my own unique output voltage and current combination according to the LED series parallel combination i choose.

 

Knowing the requirements, or being able to determine the requirements, is what is needed to produce an adequate design. So the TS will need to be able to determine those.
Creating a design for a commercial product is not within the scope of this forum, and, in addition, is far from what I am willing to provide free advice and assistance for.

For that, my free advice, "visit the IC suppliers websites" has already been given. Beyond that point, my commercial rates apply.

 

"" But for that i need to prove the financier that i can make one. ""
Well ........
It's pretty obvious that You can't.

There are hundreds of very efficient designs available.

Come up with a set of specifications for the LEDs FIRST,
including the proposed Power-Supply-Voltage / Source,
then design a Switching-Current-Regulator that will be adequate for the job,
and meet the Cost, Efficiency, and Reliability, requirements.
.
.
.

 

"" But for that i need to prove the financier that i can make one. ""
Well ........
It's pretty obvious that You can't.

There are hundreds of very efficient designs available.

Come up with a set of specifications for the LEDs FIRST,
including the proposed Power-Supply-Voltage / Source,
then design a Switching-Current-Regulator that will be adequate for the job,
and meet the Cost, Efficiency, and Reliability, requirements.
.
.
.

I got your point sir and i found the LED specs. its bridgelux 2835 LEDs.

The LED Specs are as per below:
Forward voltage: 3.1 V
Typical Forward current: 60 mA
Max forward current: 80 mA
Wattage: 0.2 watts

There are 26 in series and 5 branches of the same in parallel.
about 300 mA of constant output current required.

I succeeded in the last circuit i was trying to built with TNY278PN, all the issues are solved except the power factor(it was below 0.5 because the TNY278PN didn't have PFC in it). I have seen many other drivers too and i came to know that the buck topology is more cost effective and can provide the same results. So, please provide some guidance to built it.

 

So the constant current supply will need to be able to provide a bit over 80 volts, (3.1V x26led) and be set for 0.3 amps (5 x 60mA). OR you can choose to use a small series resistor and a constant voltage supply. Consider that the load on the supply will be about 0.3 amps x 80 volts= 24 watts.
There is also the option of using an undersized trnsformer with only enough steel core to deliver 24 watts, with a half wave rectifier and not much filtering. It would run quite hot but it would work. ( Not a good design, but possibly really cheap.)