When connected in this way (shown in the circuit below) the photodiode will start conducting some current based on the light sensed by it. That is the Anode will be connected towards the ground and the cathode will be connected to supply voltage. When it comes to using a Photodiode, one important thing to remember is that Photodiode should always be connected in reverse polarity. So if you are looking for a pair to use with your IR LED or just trying to detect light for your project then this photodiode might be the right choice for you. It is also commonly used with IR transmitter ( IR LED) to form an IR pair and used in applications like object detection, counter, encoder and much more. Due to this property of Photodiode, it is fairly used in situations where light has to be detected. When photodiodes detect light they allow some current to flow through it and the amount of current is directly proportional to the amount of the light detected by the Photodiode. IR receivers ( TSOP), Phototransistor, LDR, Photocells, Solar panels Note: Read the article further and check the photodiode datasheet attached at the end of the article to learn why these parameters are important. But inversely connected to supply voltage during usage This is the negative (ground) pin of the IR diode. But inversely connected to ground during usage This is the positive (+) pin of the IR diode. It makes it suitable to use along with the IR LEDs in IR sensor modules. Instead, when they detect light they allow some current to flow through it, and the amount of current that flows through the Photodiode is directly proportional to the amount of light detected by the Photodiode. What is Photodiode? Photodiodes, as the name suggest, are just another type of diodes having an anode and cathode similar to normal LEDs.

Identify cathode led