Open-Collector Outputs In Microcontrollers Explained
Ғылым және технология
With microcontrollers, communications protocols, timers, and other devices, you'll sometimes hear that the outputs are "open-collector outputs," which may be confusing. In this overview, Josh reviews bipolar junction transistors (BJTs) and how BJTs are used inside microcontrollers and other devices to create open-collector outputs. Besides how they are used, he explains why you want an open collector output with some microcontrollers. Once you understand how an open-collector output works, it'll make sense why I2C communication lines use open-collector outputs to control common lines between multiple devices. We also recommend checking out the written tutorial on CircuitBread.com at www.circuitbread.com/tutorial...
0:00 Introduction
0:26 Review of Bipolar Junction Transistors (BJTs)
1:00 BJT internal to the device
1:49 MOSFETs and open-drain outputs
2:47 Trade-offs of open-collector or open-drain outputs
4:00 Check out our Friends of CircuitBread
4:18 What else is there on CircuitBread.com?
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Пікірлер: 11
Great explanation. A little fast but I could rewind. Thank you for helping me understand open collectors
@CircuitBread
Ай бұрын
Good to know, Josh has been trying to slow things down when he speaks and we're trying to modify the scripts to dwell more on complicated portions of the topic. Feedback like this is great to know that we're on the right track but still have work to do. Thanks!
As soon as you started getting into the theory of operation for the transistor, I realized "Oh! It's a scheme that can sink power." *Your videos are truly superbly done.* While I often wish I had completed more schooling, I fortunately did complete enough to understand basically anything analog, and don't struggle to understand digital. I was also just reviewing a circuit I designed 15 years ago before I had any college education, and realized I'm running the op-amp class-A which is why the quest for gain in those days went through the roof. At the time, there was a lot of probing around with parts lol. I added a cap and resistor to the 1st stages output pin from the common. *I'm one of those eccentric and over the top lead/solo guitar shredders, but somehow, science has always been a more important passion.*
@CircuitBread
9 ай бұрын
That's awesome! Thanks for the feedback and I'm so glad that it was helpful! Being a guitar shredder, you made me think of an older video we did - the audio is not ideal because it was incredibly loud there, but we interviewed a guy at NAMM back in 2019 who represented a company that makes a "plasma pedal" kzread.info/dash/bejne/mICW0tuqo5nbl9o.htmlsi=mU-zxSY9d4a354ru I just love that science can push or enable our other passions! Thanks again for sharing.
Great information! Thanks and take care.
@CircuitBread
10 ай бұрын
You're welcome, I'm glad you found it interesting!
I'm surprised you didn't mention OC/OD outputs being commonly used for shared lines like on I2C. Nice and concise video, though. Thank you.
@CircuitBread
2 ай бұрын
Wow. I went and checked the written tutorial and the script I used because I thought you must have been mistaken. But you aren't! That, indeed, was an oversight. I know we mention it in passing with some of our embedded systems series and specifically in our communication series (www.circuitbread.com/tutorials/what-is-the-i2c-communication-protocol ) but I still should have included that tidbit in this video as well. Thanks for the feedback!
Very helpful, thanks ☺
@CircuitBread
10 ай бұрын
Thanks for watching and I'm happy we could help!
Thanks. What if the sensor in the field is open source or open drain? then the sourcing is done by the field device and sinking by the MCU input? I'm doing BMS controls: Priva Hardware. So we have to configure the I/O to source or sink depending on what type of field device its connected to. Love the channel.