I want to design an LED driver for 18 Watts LED panel light.

Thread Starter

PY HRM

Joined Jan 1, 2022
23
i want to design an LED driver for 18 Watts LED panel light. suggest me some ICs that are easily available in market and their design reference should be also available as i am a beginner.
 

MisterBill2

Joined Jan 23, 2018
11,646
As an electrical engineer, designing a linear regulator LED driver should not be a big challenge. So what specialization of EE are you?

For starters, though, you must provide that data requested in post #2, because creating a good design without knowing the requirements is a hard challenge. 18 watts to an LED panel is a start, but we have no hint about the LED arrangement, it might be 36 half watt LEDs in series, or some other arrangement. So knowing the required voltage is mandatory. Then we also need to know what sort of supply voltage is intended. 12 volts DC, or 24 VDC? or maybe 120 volts AC mains, or 220 volts mains.

The very simplest LED driver I have come across is simply a full wave diode bridge with a hidden resistor, feeding parallel strings of about 40 LEDs in an outside lighted decoration.
 

Thread Starter

PY HRM

Joined Jan 1, 2022
23
As an electrical engineer, designing a linear regulator LED driver should not be a big challenge. So what specialization of EE are you?
For starters, though, you must provide that data requested in post #2, because creating a good design without knowing the requirements is a hard challenge. 18 watts to an LED panel is a start, but we have no hint about the LED arrangement, it might be 36 half watt LEDs in series, or some other arrangement. So knowing the required voltage is mandatory. Then we also need to know what sort of supply voltage is intended. 12 volts DC, or 24 VDC? or maybe 120 volts AC mains, or 220 volts mains.
The very simplest LED driver I have come across is simply a full wave diode bridge with a hidden resistor, feeding parallel strings of about 40 LEDs in an outside lighted decoration.
It's 230 VAC 50Hz input and output 36.6VDC 0.45Amps(The LED panel that i have of panasonic brand). I want to design it with flyback topology. Panasonic is using BP3316D, but i can't find that in any online retail store. I tried to make one with TNY278PN, due to the last heat sink area needed it was very bad in EMI. Please suggest me some IC that i can use...
 

LowQCab

Joined Nov 6, 2012
1,931
A Flyback-Topology is probably the noisiest type of Regulator that You could build.
A Flyback-Regulator is also quite fussy about Component selection.
Why is Noise an issue for You ?

"" ....... and output must be 36.6 volts ""

LEDs must be Current-Regulated, NOT Voltage.

Do You know the Part-Number of the individual LEDs ?

How are the LEDs wired together ?

Why do You state that You need ""0.45-Amps"" ?, where did You get this number ?
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Thread Starter

PY HRM

Joined Jan 1, 2022
23
A Flyback-Topology is probably the noisiest type of Regulator that You could build.
A Flyback-Regulator is also quite fussy about Component selection.
Why is Noise an issue for You ?

"" ....... and output must be 36.6 volts ""

LEDs must be Current-Regulated, NOT Voltage.

Do You know the Part-Number of the individual LEDs ?

How are the LEDs wired together ?

Why do You state that You need ""0.45-Amps"" ?, where did You get this number ?
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I was checking a panasonic LED driver. This specifications was written on it... 0.45 amps was the output current specified and i check the output voltage by oscilloscope it was maintaining 36.6VDC in output.
 

Thread Starter

PY HRM

Joined Jan 1, 2022
23
A Flyback-Topology is probably the noisiest type of Regulator that You could build.
A Flyback-Regulator is also quite fussy about Component selection.
Why is Noise an issue for You ?

"" ....... and output must be 36.6 volts ""

LEDs must be Current-Regulated, NOT Voltage.

Do You know the Part-Number of the individual LEDs ?

How are the LEDs wired together ?

Why do You state that You need ""0.45-Amps"" ?, where did You get this number ?
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LEDs were 12 branches of 7 in series. Sorry i don't know the part number but according to the current rating of driver we can say the optimum current rating must be 37.5 mA for each LED.
 

LowQCab

Joined Nov 6, 2012
1,931
OK, this is good information, but it is not enough information.
The ""0.45-Amp"" may be the maximum Output capability of the Power-Supply,
or, it may be the "Regulated-Current" that the power-Supply is designed to deliver.

The Voltage may go up and down, but the Current must remain constant.

Have You actually measured the Current supplied by the original Power-Supply ?

If You already have a Power-Supply, why do You want to make a new Power-Supply ?

If the maximum Current that the original Power-Supply could deliver is 0.45-Amps,
then that Current must be divided by the number of Strings ,
You have 12-Strings, (Branches), 0.45 divided by 12 = 0.0375-Amps, or, 37.5ma..
37.5ma. "may" or "may not be" too much Current for the LEDs.
Cheap, generic LEDs usually can not withstand more than ~20ma. for long periods,
but there are certainly some, more specialized LEDs, which are rated for much more Current.

If You measured the Output-Voltage of the Power-Supply,
while it is powering the LED-Panel,
and it was 36.6-Volts,
then each LED has a "Forward-Voltage-Rating" of 36.6 divided by 7 = 5.23-Volts per LED.
This is an unusually high "Forward-Voltage" for an LED.
Does the LED-Panel normally operate at 36.6V Input-Voltage ?

Why do You want to build a new Power-Supply for your LEDs ?
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Thread Starter

PY HRM

Joined Jan 1, 2022
23
OK, this is good information, but it is not enough information.
The ""0.45-Amp"" may be the maximum Output capability of the Power-Supply,
or, it may be the "Regulated-Current" that the power-Supply is designed to deliver.

The Voltage may go up and down, but the Current must remain constant.

Have You actually measured the Current supplied by the original Power-Supply ?

If You already have a Power-Supply, why do You want to make a new Power-Supply ?

If the maximum Current that the original Power-Supply could deliver is 0.45-Amps,
then that Current must be divided by the number of Strings ,
You have 12-Strings, (Branches), 0.45 divided by 12 = 0.0375-Amps, or, 37.5ma..
37.5ma. "may" or "may not be" too much Current for the LEDs.
Cheap, generic LEDs usually can not withstand more than ~20ma. for long periods,
but there are certainly some, more specialized LEDs, which are rated for much more Current.

If You measured the Output-Voltage of the Power-Supply,
while it is powering the LED-Panel,
and it was 36.6-Volts,
then each LED has a "Forward-Voltage-Rating" of 36.6 divided by 7 = 5.23-Volts per LED.
This is an unusually high "Forward-Voltage" for an LED.
Does the LED-Panel normally operate at 36.6V Input-Voltage ?

Why do You want to build a new Power-Supply for your LEDs ?
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.
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I was designing an LED driver for a new startup, but the issue is that i don't know which IC to use, i tried to get BP3316D(IC used in panasonic driver) but i couldn't find it in any online store, so i thought to find some alternative.

I have not measured the current actually as it was written on the driver that it is a contast current driver and in the circuit i tried TNY278PN have an internal current limmiting feature so i kept that and it runs well. The issue is that it needs a last amount of heat sinking area and it is too much. Without that i was getting thermal shutdown in just 10 minutes. It actually works on pulse skipping method instead of PWM, but i didn't have any other good choice available on online stores so i tried that.

Please suggest me some good driver IC that i can use as an alternative of BP3316D. Here I'm attaching the datasheet of that IC for reference.
 

Attachments

LowQCab

Joined Nov 6, 2012
1,931
If You can't figure out what the Specs of your LEDs are,
You are very likely to either, smoke them, or not get their full performance potential.
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MisterBill2

Joined Jan 23, 2018
11,646
Modern illumination type LEDs usually run at much more than 20 mA, and the white ones usually have a forward voltage drop of around 3.3 volts, although that varies quite a bit. 20 mA is a good max value fot the plastic molded 5mm LEDs, but not applicable for the high powered chip devices.

I am guessing that the 450 mA came from dividing the rated watts by the given rated volts 18/36.6=about 0.45A=450 mA. So 450mA is a reasonable supply capability.

Now the big question: Is this a one off creation or is this LED driver to be a product for sale? For a one unit application it will be far better to use a purchased modular power supply, because, as already mentioned, switcher supplies as a whole, and flyback supplies in particular, are very critical in every aspect, both in components and in circuit board layout. In addition, as you have discovered, they tend to be a noisier type of switching supply. And if minimum cost is a design goal, then adequate noise filtering will be a higher cost problem.
Several semiconductor companies have free design programs on their websites that can do a VERY GOOD JOB of designing the circuit and selecting the components for switcher supplies. I suggest visiting them. And avoid all of the cartoons on yootoob.
 

Ian0

Joined Aug 7, 2020
4,904
A Flyback-Topology is probably the noisiest type of Regulator that You could build.
A Flyback-Regulator is also quite fussy about Component selection.
Why is Noise an issue for You ?
Whilst I agree in principle, flyback is also the most common and the one most supported by silicon, therefore the most cost-effective
Add an extra inductor and a capacitor to a flyback and you can make a SEPIC which is much quieter on the supply side.
Or use that extra inductor and capacitor to make a filter to keep the flyback noise out of the mains.
 

LowQCab

Joined Nov 6, 2012
1,931
"" flyback is also the most common and the one most supported by silicon, therefore the most cost-effective ""
In a Professionally-Designed, Mass-Production Project........
Is that what this is ?, I still have no clue.

It's not like it's hard to find a Chip for certain types of Topologies,
even with the Chip availability problems we're having recently.

Not enough information to make any kind of a reasonable suggestion.
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MisterBill2

Joined Jan 23, 2018
11,646
The current shortage is primarily in the newest processor devices. The one with the even narrower gaps and lines on the die, that demand the new production equipment that is even more expensive and longer lead times for delivery. The latest and greatest for all of those smart modules that marketing demanded be added to every product.
Shortages of the more mature products would be due to a lack of production workers. Quite different.
 

Thread Starter

PY HRM

Joined Jan 1, 2022
23
Modern illumination type LEDs usually run at much more than 20 mA, and the white ones usually have a forward voltage drop of around 3.3 volts, although that varies quite a bit. 20 mA is a good max value fot the plastic molded 5mm LEDs, but not applicable for the high powered chip devices.

I am guessing that the 450 mA came from dividing the rated watts by the given rated volts 18/36.6=about 0.45A=450 mA. So 450mA is a reasonable supply capability.

Now the big question: Is this a one off creation or is this LED driver to be a product for sale? For a one unit application it will be far better to use a purchased modular power supply, because, as already mentioned, switcher supplies as a whole, and flyback supplies in particular, are very critical in every aspect, both in components and in circuit board layout. In addition, as you have discovered, they tend to be a noisier type of switching supply. And if minimum cost is a design goal, then adequate noise filtering will be a higher cost problem.
Several semiconductor companies have free design programs on their websites that can do a VERY GOOD JOB of designing the circuit and selecting the components for switcher supplies. I suggest visiting them. And avoid all of the cartoons on yootoob.
Thank you... Yes I'm going develop it for mass production only. Are there any particular suggestions website i can prefer? I will check and try to myself too. This will help much...
 
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