PMP4484: Another Transformer Design with Small footprints

Amit Tandel98

Part Number: PMP4484
Other Parts Discussed in Thread: LM3414, LM3414HV, UCC28810

Hi Linda,

The transformer design which you have given (Core: EDR3909, PC95) has larger footprints in terms of length. I want to restrict the length of driver to 65mm & width 55mm. Please give me another transformer which have small footprints to accommodate in the given dimension.

Regards,

Amit

over 5 years ago

0 Linda Ye over 5 years ago

TI__Intellectual 1110 points

Amit，

Is there any limit for heigh?

Linda

0 Amit Tandel98 over 5 years ago in reply to Linda Ye

Prodigy 230 points

Hi Linda,

Total height of driver including enclosure is 30mm.

Regards,

Amit

0 Linda Ye over 5 years ago in reply to Amit Tandel98

TI__Intellectual 1110 points

Amit，

Got it，I will calculate a new transformer and send the spec to you tomorrow.

Linda

0 Linda Ye over 5 years ago in reply to Linda Ye

TI__Intellectual 1110 points

25W LED Driver Transformer.pdfAmit,

Please find the attached transformer spec. The transformer is based on your last request: 50V and 25W output.

0 Amit Tandel98 over 5 years ago in reply to Linda Ye

Prodigy 230 points

Hi Linda,

Can I use same transformer for 40V, 40W output?

Regards,

Amit

0 Amit Tandel98 over 5 years ago in reply to Amit Tandel98

Prodigy 230 points

Hi Linda,

Please help me to find out out part numbers and footprint for following components in the BOM.

Component	Qty	Description	Footprint	Value	Part number	Manufacturer
L1	1	Inductor, Wirewound, Ferrite, 1 mH, TH	D8*10	1mH		Wurth
L2	1	Coupled inductor, 510uH, TH		510uH		Wurth
L3	1	Coupled inductor, 10 mH, 0.7 A, 0.35 ohm, TH		10mH		Wurth
L4	1	Inductor, Shielded Drum Core, Metal Composite, 68 μH, 0.22 A, 1.15 ohm, SMD	WE-TPC_3816	68μH	744031680	Wurth
L5, L6	2	Inductor, Unshielded Drum Core, Ferrite, 4.3 μH	IND_WE-TI_XS	6.5μH		Wurth
R53, R54	2	Resistor, 1W, 1%		1.5M

Regards,

Amit

0 Linda Ye over 5 years ago in reply to Amit Tandel98

TI__Intellectual 1110 points

Hi Amit,

Is the output 24W, 2 rail 40V 0.3A LED? I designed the transformer based on 50V voltage at C38 for LM3414 input, it can't support 40W output. Can you send out your schematic?

Regards,

Linda

0 Amit Tandel98 over 5 years ago in reply to Linda Ye

Prodigy 230 points

Hi Linda,

As per LM3414HV datasheet, it supports 4.5V to 65V and Adjustable Constant LED Current From 350mA to 1000mA. So ideally I should be able to drive LED strip of 40V @ 1000mA current which is 40W similar to 40V @ 600mA giving 24W. Basically I want to use this driver for multiple wattage-output. Now let me know if transformer will be able to provide this variable power or not. If not, what is another solution? Also give me footprints and part number of components mentioned in the previous feed.

Regards,

Amit

0 Linda Ye over 5 years ago in reply to Amit Tandel98

TI__Intellectual 1110 points

Hi Amit,

The transformer can't support 40W, it is for 25W design. You should select a larger transformer for 40W.

For this new design, not only the transformer, some components such as inductors, resistors need to change. Can you contact TI local FAE to support?

Regards,

Linda

0 Amit Tandel98 over 5 years ago in reply to Linda Ye

Prodigy 230 points

Hi Linda,

Please let me know minimum and maximum wattage output range this transformer can allow. Also give me contact details of local FAE near Mumbai.

Regards

Amit

0 Linda Ye over 5 years ago in reply to Amit Tandel98

TI__Intellectual 1110 points

Hi Amit,

The maximum wattage output is 25W. Vikas is TI India mass market FAE, you can contact him with vikas.chola@ti.com.

Regards
Linda

0 Amit Tandel98 over 5 years ago in reply to Amit Tandel98

Prodigy 230 points

Hi Linda,

Please send me following document in excel format. I have pdf copy of the same. I want editable copy. I want to use the same document to design 40W transformer (40V, 1A).

UCC28810 25W FLYBACK PFC LED LIGHTING POWER CONTROLLER Transformer Design

Regards,

Amit

0 Linda Ye over 5 years ago in reply to Amit Tandel98

TI__Intellectual 1110 points

Hi Amit,

I haven't the pfd and excel format documents.

Regards

Linda

0 Amit Tandel98 over 5 years ago in reply to Linda Ye

Prodigy 230 points

Hi Linda,

In case of mismatch in values of components in schematic and in BOM, which value to be considered valid? For example for L2, BOM says 510uH whereas schematic says 10mH.

Regards,

Amit

0 Linda Ye over 5 years ago in reply to Amit Tandel98

TI__Intellectual 1110 points

Hi Amit,

510uH is the correct value for L2.

Regards

Linda

0 Amit Tandel98 over 5 years ago in reply to Amit Tandel98

Prodigy 230 points

Hi Linda,

Can you provide me the Power Supply Design Layout guidelines for track thickness, critical nets, track to track clearance, ground shielding etc., if you have any.

Thanks.

Amit

0 Linda Ye over 5 years ago in reply to Amit Tandel98

TI__Intellectual 1110 points

Amit，

I am on labour holiday，will reply you when I back to the office tomorrow.

Regards

Linda

0 Linda Ye over 5 years ago in reply to Linda Ye

TI__Intellectual 1110 points

Hi Amit,

1. Place C15, C17 close to U1.

2. Arrange the components to minimize the loop areas of the switching currents as much as possible. These areas include such loops as the transformer primary winding current loop, the MOSFET gate-drive loop, the primary snubber loop, the auxiliary winding loop and the secondary output current loop.

3. For LM3414, keep the copper traces connecting the inductor, power switch and rectifier short and thick. Also need to minimize the loop areas of the switching currents as much as possible.

Regards,

Linda

0 Amit Tandel98 over 5 years ago in reply to Linda Ye

Prodigy 230 points

Hi Linda,

I need values of following components for 40W design. My transformer will be of 40V@1A power.

Component	Qty	Description	Footprint	Value	Part number
L1	1	Inductor, Wirewound, Ferrite, TH
L2	1	Coupled inductor, TH
L3	1	Coupled inductor, TH
L4	1	Inductor, Shielded Drum Core, Metal Composite, SMD

Also, If I use same design for 25W application, do I need to change values of above components and other components? If yes, please let me know the list of those components.

Thanks & regards,

Amit

0 Linda Ye over 5 years ago in reply to Amit Tandel98

TI__Intellectual 1110 points

Hi Amit,

Please find the part numbers for L1 - L4 from Wurth.

L1	7447480102
L2	744841247
L3	7448640415
L4	744031680

BTW, for L1 - L3, You can change them base on the EMI test result.

Regards,

Linda Ye

Simulation, hardware & system design tools

Simulation, hardware & system design tools forum

PMP4484: Another Transformer Design with Small footprints