# What are these LEDs called?

I am currently changing the SMD LEDs in my car! I wanted to change these tiny green ones but im actually not sure what they are called or what i would be looking for. I want them blue but any help would be great! Thank you so much

Hello Cyberdude10.pk and welcome to the forum,

You would have to take a measurment of the Length and width and pull similar parts from our LED discrete filter; See here and plug in your measured size ot the “size / dimension” filter.

Be aware, blue LEDs usually operate at > 3V (3.2 to 3.6) whereas other colors operate at around 2V (1.7 to 2.2). So brightness, and sometimes turning on at all, may be affected depending on the specific drive circuit.

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To Paul’s point, I would recommend you actually measure the voltage across the LED while turned on, to be certain. SOME green LED’s do operate in the 3V range, depending on the chemistry used. Green LEDs produced using InGaN (indium gallium nitride) require 3+ volts to properly light up. Modern blue LEDs also use InGaN, which requires a voltage in the neighborhood of 3V.

Here are two similar looking LEDs, one of which requires about 2.1V, whereas the other requires around 3.3V:

AA2214CGSK requires 2.1V
AA2214ZGS requires 3.3V

Both look identical:

So the only way to tell is to measure it. If your LED is of the lower 2.1-ish volt range, then you will need to figure out how the LED is driven. If the current is controlled by a simple resistor, then you will need to replace that resistor with an appropriate value. Here’s a calculator to help you figure that out. You will need to find the forward current and forward voltage in the datasheet of the blue LED you choose to calculate what resistor value is optimal.

If the current is controlled by a constant current driver rather than a resistor, then it should work directly, as long as the driver’s maximum output voltage is at or above the the forward voltage of the blue LED.

Here are some blue ones which have similar looking package types. Be sure to measure the dimensions of your LED to confirm the fit.

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Thank you everyone so much for the information. I am brand new to all of this other than sesoldering and soldering my LEDs on my cluster in my BMW. I had so much fun doing it and did everything right! So taking the next step to these small ones is next. I am struggling a lot to find what lights would work. I believe it is controlled by a constant current driver because its on my car. And its all ran when the car turns on. But I could be completely wrong with that. Here are the two pictures of me measuring the dimensions of the lights…something like 2mm x 1.15mm? I took two pictures of each measurement because the first angle was difficult

They could also be 2.00mm x 1.25mm…its hard to say for me. Im so sorry for the questions or for having such little knowledge at the moment. I appreciate everyones time and responses so far! I am already learning a lot! Cheers!

Okay so I was out to lunch on my measurement hahaha. It was 2.00mm x 1.40mm. I found the correct one here! https://www.digikey.ca/en/products/detail/qt-brightek-qtb/QBLP675-IB-2897/10401012

I will update when I solder them! Thank you.

Sounds good! That looks like the right choice.

Make sure you get your polarity right. If backwards, it’ll either not turn on, or if the voltage exceeds about 5V, it will kill it.

QBLP675-IB-2897 drawing: