Convert light to electric current.
Description:
A photodiode allows current to flow backward through it proportional to the light it absorbs.
How It Works:
This device works like a reverse LED - when the junction of its materials is exposed to light, then electric current or voltage is generated, depending on how it is connected.
Connect It:
This device has two wire leads and is polarized. It is often connected backward (reverse biased) to read a change in current via a microcontroller's analog input.
How It Is Used:
Select the device during simulation to show a slider representing light level. Slide the target to change the simulated light level.
Get Started:
Drag the starter circuit below into your design for a working example of how to use this part.
More About Photodiode:
To add a Photodiode in Tinkercad, search for "Photodiode" in the component library, drag it onto your breadboard, and connect its terminals with wires to other components in your circuit. You can then click on the Photodiode to set its name for easy identification.
Photodiodes are semiconductor devices that generate a photocurrent when exposed to light. They are widely used in optical communication systems, light meters, and other light-sensing applications. The two primary types of photodiodes are standard photodiodes and avalanche photodiodes (APDs). Standard photodiodes operate in photovoltaic mode (without an external bias) or photoconductive mode (with reverse bias), where the photocurrent generated is proportional to the incident light intensity. Avalanche photodiodes (APDs) are operated with higher reverse bias and offer greater sensitivity, amplifying the photocurrent through an avalanche effect. Key specifications for photodiodes include their wavelength range, typically spanning from 300 nm to 1100 nm, depending on the material (e.g., silicon, germanium, or InGaAs). The responsivity defines how effectively the photodiode converts light into current, usually expressed in A/W (amperes per watt). The dark current, or the current that flows through the photodiode in the absence of light, is typically very low, ranging from picoamperes (pA) to nanoamperes (nA). The reverse voltage rating for standard photodiodes is usually between 10V to 100V, while APDs require higher reverse biases, typically between 100V and 300V. Power rating for photodiodes generally ranges from 10mW to 50mW, and they often operate in temperatures ranging from -40°C to +85°C. The units for these specifications include volts (V) for reverse bias voltage, amps (A) for current, watts (W) for power, and degrees Celsius (°C) for temperature. The rise time (response speed) and quantum efficiency are also important parameters, affecting how quickly and efficiently the photodiode responds to light changes.
1. Electronics Tutorials
Website Title: Electronics Tutorials
Website Page URL: https://www.electronics-tutorials.ws/io/photodiode.html
URL recommended for: A comprehensive explanation of photodiodes, including how they work, their types, and applications. Great for beginners who want a fundamental understanding of photodiodes.
2. All About Circuits
Website Title: All About Circuits
Website Page URL: https://www.allaboutcircuits.com/textbook/semiconductors/chpt-6/photodiodes/
URL recommended for: A detailed textbook-style resource on photodiodes, covering their theory, construction, and various uses. It’s excellent for both beginners and intermediate learners.
3. Digi-Key Electronics - Photodiodes
Website Title: Digi-Key Electronics
Website Page URL: https://www.digikey.com/en/products/filter/photodiodes/748
URL recommended for: A wide selection of photodiodes with datasheets and technical specifications. Ideal for learning more about specific components, their ratings, and applications in real-world projects.
4. RS Components - Photodiodes
Website Title: RS Components
Website Page URL: https://uk.rs-online.com/web/c/semiconductors/optoelectronics/photodiodes/
URL recommended for: An extensive catalog of photodiodes with product datasheets and specifications. This is a great resource for understanding different photodiode options and selecting the right one for projects.
5. Adafruit - Light Sensors (Photodiodes)
Website Title: Adafruit
Website Page URL: https://learn.adafruit.com/photocells
URL recommended for: While primarily focused on light sensors, this guide covers photodiodes as part of their light-sensitive components. Excellent for hands-on learning and DIY project ideas.
6. National Instruments - Photodiodes
Website Title: National Instruments
Website Page URL: https://www.ni.com/en-us/innovations/photodiodes.html
URL recommended for: A highly technical resource that discusses the role of photodiodes in scientific measurements and instrumentation. Useful for those looking for more advanced applications of photodiodes.
7. OptoSigma - Photodiodes
Website Title: OptoSigma
Website Page URL: https://www.optosigma.com/us/en/products/optoelectronics/photodiodes
URL recommended for: An in-depth overview of various photodiodes, including high-sensitivity and high-speed options. Great for understanding the wide range of photodiodes used in optoelectronic applications.
8. Learn Spark - Photodiodes and Light Sensors
Website Title: Learn Spark
Website Page URL: https://learn.sparkfun.com/tutorials/light-sensors
URL recommended for: A simple, beginner-friendly guide on light sensors, including photodiodes. Includes practical examples and tutorials to help you understand their use in circuits.
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