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rost. , 06-17-2025, 05:23 PM

Hey, I designed a usb-c led board, with 4x 730nm Leds and a TPS61169 led driver from Texas Instruments. The driver is configurated to supply around 7,5W in total for the leds.

**Input:** 5V 2A max.
**Output:** ca. 9,6V 0,75A
**PCB beasurements:** 80x60x1,6mm

Do you guys think, it will be ok in terms of temps? Im planning to use 1,6mm FR4.
Im not too worried about the led driver, the LEDs are stressing me ab bit.

Also dont mind minor design mistakes, im not an engineer or something, its just something i wanna use in my garden :D. If it works im fine with it, im not really sure what im doing at all in terms of design.

**TPS61169 datasheet:** https://www.ti.com/lit/ds/symlink/tps61169.pdf

**LED datasheet:**https://ams-osram.com/de/products/leds/color-leds/osram-oslon-optimal-gf-cssrml-24

The layout is in the attachments. Im planning to flood the first layer with gnd, but havent done this yet (fyi).
**L1: RED**
**L2:BLUE**

Thanks for your advice :)))

QDrives , 06-17-2025, 10:35 PM

750mA is more then twice the characteristic current of 350mA.
Thermal resistance to the pads is just 2K/W, but how are you going to get the ~1.7W away from the LED?
Copper thickness?
Layers?

rost. , 06-17-2025, 11:52 PM

Hey, thanks for your quick response.

My first approach were the vias placed next to the leds, but it sounds like it wont work that well, right?

The second approach would be changing the fr4 to an aluminium core pcb, and due to cost reduce everything to one layer.

Do you think its possible with no downsides, to reduce everything to one layer?

rost. , 06-17-2025, 11:55 PM

rost. , 06-17-2025, 11:56 PM

thats how i would do the single layer design (ill remove the vias and fix up the clearances)

QDrives , 06-18-2025, 12:00 AM

IMS is quite commonly used for LED lighting.

rost. , 06-18-2025, 12:03 AM

alright, ill try that.
But i can only use one layer, the step up converter should still work, right?

rost. , 06-18-2025, 12:03 AM

thanks for your advice!

QDrives , 06-18-2025, 07:13 PM

Most IMS boards can only be a single layer.
You can place 0 ohm resistors as jumpers.
I do not know of your step up converter as you do not provide enough data.