# KIMISS Led 3W with CAT4101 driver?

**URL:** <https://forum.arduino.cc/t/kimiss-led-3w-with-cat4101-driver/1409385>\
**Category:** Displays\
**Created:** [October 13, 2025, 4:07pm UTC](https://forum.arduino.cc/t/kimiss-led-3w-with-cat4101-driver/1409385 "2025-10-13T16:07:18Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![giovanniguerra](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/giovanniguerra/32/227267_2.png) [@giovanniguerra](https://forum.arduino.cc/u/giovanniguerra)\
**Post date:** [October 13, 2025, 4:07pm UTC](https://forum.arduino.cc/t/kimiss-led-3w-with-cat4101-driver/1409385/1 "2025-10-13T16:07:18Z")

</div>

I’d like to driver the high power LED KIMISS Led 3W:

 ![image](https://europe1.discourse-cdn.com/arduino/original/4X/c/d/3/cd3245709505388979c1914765bc68aaa0b19282.png)

(Annoyingly Amazon does not give the current required, I can only guess that 3W/3.4V means it is a bit less than 1A.)

This driver seems to fit the bill: CAT4101:

 ![image](https://europe1.discourse-cdn.com/arduino/original/4X/5/9/a/59a5707f51d71b25575dcb4b4270771f49521d0d.png)

Am I right?

Tia

---

<div class="post-metadata">

**Author:** ![kmin](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/kmin/32/1147370_2.png) [@kmin](https://forum.arduino.cc/u/kmin)\
**Post date:** [October 13, 2025, 5:02pm UTC](https://forum.arduino.cc/t/kimiss-led-3w-with-cat4101-driver/1409385/2 "2025-10-13T17:02:16Z")

</div>

Those kind of "3W" LEDs are usually rated for 650-750mA. And will get hot at that current. Fix them to some heat sink if you drive them at max power.  
So if the driver you were looking at is adjustable, should be ok. Otherwise some fixed max 700mA driver.

> **[3W%20LED.pdf](https://cdn.sparkfun.com/datasheets/Components/LED/3W%20LED.pdf)**
>
> 367.13 KB

This would go up to 660mA and give you pwm control.

> **[FemtoBuck LED Driver](https://www.sparkfun.com/femtobuck-led-driver.html)**
>
> This is the FemtoBuck, a small-size single-output constant current LED driver. Each FemtoBuck has the capability to dim a single high-power channel of LEDs from 0-350mA at up to 36V while the dimming control can be either accessed via PWM or analog...

---

<div class="post-metadata">

**Author:** ![DVDdoug](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/dvddoug/32/671533_2.png) [@DVDdoug](https://forum.arduino.cc/u/DVDdoug)\
**Post date:** [October 13, 2025, 5:08pm UTC](https://forum.arduino.cc/t/kimiss-led-3w-with-cat4101-driver/1409385/3 "2025-10-13T17:08:59Z")

</div>

Power (wattage) is calculated as Voltage x Current. 3W / 3.4V = **0.88 Amps.**

The CAT4101 looks OK but make sure you understand what the datasheet says about power dissipation. With a linear device like this, the power dissipated by the driver is the the voltage _dropped_ across the driver multiplied by the current. i.e. If you feed it 5V, that's (5 - 3.4) x 0.88 = 1.4W.

Switch-mode drivers/regulators/power supplies are MUCH more efficient. They run cooler but the circuitry is more complicated.

---

<div class="post-metadata">

**Author:** ![giovanniguerra](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/giovanniguerra/32/227267_2.png) [@giovanniguerra](https://forum.arduino.cc/u/giovanniguerra)\
**Post date:** [October 14, 2025, 4:14am UTC](https://forum.arduino.cc/t/kimiss-led-3w-with-cat4101-driver/1409385/4 "2025-10-14T04:14:56Z")

</div>

> [@DVDdoug](#):
>
> Switch-mode drivers/regulators/power supplies

But aren’t they bigger and more expensive?

---

<div class="post-metadata">

**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\
**Post date:** [April 12, 2026, 4:15am UTC](https://forum.arduino.cc/t/kimiss-led-3w-with-cat4101-driver/1409385/5 "2026-04-12T04:15:02Z")

</div>

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.