How to #2 - Use LTC3780


Introduction: How to #2 - Use LTC3780

About: Hi, I'm Nemeen, Electronics Enthusiast! I have seen a huge decline in electronics hobbyist in past few years. I started this channel in order to inspire you to create. Hopefully, you will find something tha...

This is a Buck Boost converter, which is a kind of high efficient power supply module with Constant voltage, constant current, under-voltage protection.

What is Buck Converter ?

It can step down the voltage

What is boost converter ?

It can step up the voltage

And This LTC3780 is Buck boost converter !

If you want to watch the video Click Here

And do check out my channel Click Here

Step 1: What Are These Pots ?

Far right one is for Under voltage protection (VV) and it is mostly used for Solar Charging

What does it mean ?

The device can monitor a DC-DC output voltage and quickly disconnect the power source from the DC-DC input load when an overvoltage condition occurs. A power-OK output signals when the DC-DC input voltage falls below an adjustable threshold.

Center one is for Constant Current ( CC)

What does it mean ?

A constant current is that does not change its intensity with time.

Left one is for Constant Voltage ( CV )

What does it mean ?

Same as CC does not change over time

Step 2: How Much Power Can It Handle ? and Efficiency ?

It depends on the board the one which I have used can handle Up to 130W

But after 80W it needs to increase the Heat Dissipation


The sweet spot for the efficiency is 98% at 12V

Step 3: Lets Power It Up !

I had a bunch of LED's soldered in parallel

After powering it up I have to say it worked like charm and I was able to control the voltage and current to change the intensity of the LED's

Step 4: Ending Notes

From where I got mine ?

Gearbest - Click Here

LTC3780 - Click Here

Volt Amp Display - Click Here

Shipping Time ?

It took 2 weeks for me to reach India

Packaging ?

Excellent Static proof bags with bubble wrap in it

Note - In the Next Instructables And video I am going the built a power Supply out of it !

So For updates you can check my Youtube Channel, Facebook And Instagram

Hope you like this Instructables

Happy Making !



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    14 Discussions

    Nice useful instructable

    Can i power it up using 24v 5A and if i do wil the output voltage and current be higher?

    what resistor value on the CC terminals would set it wide open (no current limit) Im trying to save space and the pots are slightly higher than the caps so Im taking them off for a thinner case. I need 24-26v (currently resistors replacing CV are giving 26) and no limit on amperage. The device attached draws 2amps max but im not quite sure how to tell if its limited by the 3780/psu or not as i cant force device to max power and dont have power resistors I wouldnt turn red hot

    Hello ! I tried to used one of those for a variable psu however when I tried powering up the board, it wouldn't output anything and the FAULT led was lit.. I powered it up with a 12V playstation3 power supply and tries measuring the output voltage using a voltmeter. Did I do something wrong or was it just a doa board ? Could anyone help me please :)

    4 replies

    That didn't work for me as I am having the same problem but turning the 3rd pot did nothing

    I eventually figured out the solution which was indeed turning the 3rd pot. However it is a multiturn pot with no locking so you have to try turning it many times in each directions. The FAULT led also turns on if your outputs are directly connected or if the input voltage is too high

    I didn't realise how many times you could turn the pot! I kept turning until the fault led turned off. I wish it would have been mentioned in the video that this was necessary instead of saying we didn't need to touch it but I got it working. Thanks so much for your help!

    I have one which outputs stuff correctly. but the OP amp gets TOASTY! I used a tiny heatsink on the op amp (lm358).

    can anyone tell me if their's do that too? because litteraly the second Ibought it I accidentally smashed the circuit with my screw driver while adjusting those annoying pots :D

    sadly the second one I bought had the same thing happen to it. only this time it made a giant spark on constant and now it gives me a constant 2.3v and the ltc3780 heats up very quickly


    1 year ago

    Hi can i power it using a 12 volt2 amp adapter (the tata sky ones)

    2 replies

    Yes but you won't be able to exceed 24W power I would recommended getting one 12v 5A or 10A smps

    Sir can i power it with a atx power supply and can i power it more than 10amp power supply please help me.

    can i change the current pot whit a 220k ohm pot impart from the 200k pot?

    1 reply

    Yes it won't make any difference because it is making voltage difference if doesn't works let me know