LDO Regulator Hardware Design - Phil's Lab
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- Опубликовано: 16 июн 2024
- How low-dropout (LDO) regulators work, when they should(n't) be used, LDO datasheets, key parameters to choose, power dissipation and thermals, and PCB layout/routing demo. PCBs by PCBWay www.pcbway.com
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forms.gle/X4jwvtZeJ1jTXh7r9
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[TIMESTAMPS]
00:00 Introduction & Basics
01:57 Altium Designer Free Trial
02:35 PCBWay
03:04 Reasons for Using LDOs
04:19 How LDOs Work
09:31 Power Dissipation Calculation
10:58 Datasheet & Key Parameters
15:05 Input/Output Capacitors and Derating
17:01 Cascading Switching and LDO Regulators
18:15 Example Design
19:34 Layout & Routing
25:47 Outro 
Наука
this channel is the goldmine for novice electrical engineers. Thank you so much.
Thank you thank you thank you! Cannot thank you enough for teaching all of us and helping us build foundations in electronics and PCB design!
My pleasure - thank you very much for watching!
@@PhilsLab I am having some trouble with a topic. Eveywhere I see the concept of characteristic impedance and PCB tracks is covered in detail. But how to match via impedance with track impedance and how to ensure that via does not cause SI problems in high speed signals is not covered in detail anywhere. What do I do?
@@user-ww2lc1yo9c About via effect to transmission line (SI problem you mentioned), probably there're just few methods to minimize your concerns.
1. Put extra vias connected to your return path (may be a soild ground plane or a specific power plane. Depend on your chip driver design) near the vias of your signal transition.
2. From the PCB design, can try back drill or HDI design to minimize the drop of impedance caused by via
Via isn't always critical. It depends on rise time need of your digital signals running on the PCB. If the rise time isn't too short and longer enough in your design, I think a little bit impedance drop caused by via should be acceptable.
Hopefully, this info is helpful to you.😁
Great video. It's the first time I see someone explain this topic with block diagram. Clear enough.
What a good explanation, Phil! I love learning with all your teachings and advices.
Thank you, Teddy!
Phil you're a star! I love your vids but quite often struggle to keep up as I'm just a hobbyist. This vid was just what I was looking for. Clearly explained and has set me on the correct path for the regulation I need.
Cheers!
Matt
What I like the most in these videos, is that I get knew interesting IC models every time. For instance, it was good to find out a better alternative to lm317, with a lower output noise at the same price.
Glad to hear that the vids are useful in that way as well, thanks!
Couldn't agree more. And actually it would be great if Phil could post a video with suggestions for some standard parts, which are easy to use, reliable and of course cheap at pcbways and / or jlcpcb. Finding parts takes such a lot of time, and without experience you often don't have the slightest idea what to look for.
Thank you very much for all you do for us Mr Philips
Thank you for watching, Augustin :)
At last something for noobies
Thanks Phil for another great presentation.
Thank you for watching!
This is an EXCELLENT video - well done. Subscribed!
Thank you!
Thank you for sharing you knowledge 🙏
Really good video, thanks!
Thank you, Stephen!
Thank you! One thing I keep hoping for is to see you build a logic analyzer maybe just the front end if that is easier
Great video as always!
Thank you, Biko!
I was looking for a video from you about this topic like 10 hours ago and you uploaded one right after 😂
Yay, glad to hear that :)
Nice tutorial 👍
Thank you!
Normally I find your videos too complex for me but this one was perfect!!
Glad to hear this one was just right! Any other topics you'd be interested in?
@@PhilsLab I find all your videos interesting to watch. You explain it well. There are plenty of interesting topics. For example, I'm trying to copy the fs1000a module myself to use in my own pcb, but I don't understand it yet. There is also little information about a 433mhz pcb antenna. I am also curious what determines the efficiency of a boost converter and how you can possibly improve it. I am also curious about programming the cheaper microcontrollers such as the padouk or ch32v003 microcontrollers. But like I said. Find all your videos very interesting to watch! So keep it up!!
@@PhilsLab But what might suit your videos more.... Maybe you could make a video explaining how to properly read a schematic off a datasheet. As an example the IP5306 (power bank) ic. In the schematic you see different input and output capacitors. What are they for and how do you know which capacitor should be placed close to the IC. Perhaps you can share some general tips with us to read a schematic properly and translate it into a pcb.
Those are great ideas, thank you! 'How to read a datasheet' is something I actually wanted to record in the very-near future.
@@PhilsLab That is amazing. I eagerly await that video!!
Great lesson! thanks a lot
Thanks!
Much appreciated. Thank you.
Thanks for watching!
Usual linear regulator --> uses darlington transistor, which drops more voltage across itself (Darlington has higher Vce drop), but needs less base current drive.
LDO --> Uses 1 transistor (PNP), which drops less voltage across itself, but needs more current to drive the base. This current is not seen in the output, but is used by LDO to operate itself.
Thank you very much
Great work Phil, always worth the time to watch. When's your FPGA course due to be released? I am eagerly awaiting it 🙂
Thank you, Dean! Within the next 1-2 weeks. I've uploaded more than half the content already. Will make a video once it's released!
It would be bice to know also how you arrangeg ground around and near the LDO and see traces that carry voltage to components.
thanks
Just the tutorial i needed! Would you consider doing a video on power switching? I.e switching from battery power to usb power when it is plugged in. This is a topic i can't seem to find much information on. Thanks!
Thanks, Henry! Yeah, that's actually a great idea :)
please provide video to calculate power budget of an existing hardware design
A video tuto on ferrite bead please!
Hi, amazing video. I'm complete beginner and I was able understand stuff. I have a question, for the power supply design what documents would u suggest me to go through to find if I should use a SMPS or a LDO in my design, what were the documents that u referred for the circuit in this video. a small comment would be really helpful. thanks
Great vdo once again. When you are moving a component the designator is becoming visible ? How to turn on this function in Altium ?
Hi Phil, Can't we use the NC Pin 7&2 with VCC and 3V3 respectively for better power delivery
Nice...cheers.
Thanks, Andy!
Cheese!
Question - if I use cascaded LDOs, with the first meant to regulate from 12V to 5V and the second from that same 5V to 3.3V, what will the output voltage of the first LDO be if it is only provided 5V? Will the output just be unregulated, after a body diode voltage drop of the "pass element" of the first LDO?
In general, if you apply a lower input voltage than the 'set' output voltage, the output voltage will decrease linearly with the input voltage (e.g. input minus ~dropout). The datasheet should provide a graph of output vs input voltage.
Thank you so much for these awesome videos. Do you think you could make videos about rf video transmission in digital and analog ways? I think it would fit really well because you have great experience with FPGA's and analog circuitry. Greetings from Germany.
Moin, I'd like to make more videos on RF - however, haven't had much personal need. But I'll see what I can do :)
For large current LDOs how would you chose the heatsink? Also would you ever consider making a LDO from discrete parts? (asking since there was some question from sometime ago about regulated 115V from rectified mains in the US, but it was low power , and that made me think that a discrete LDO could be used there )
Figure out power dissipated in the LDO, use the thermal resistance of the LDO package to figure out temperature rise, calculate required parameters of heatsink. I'd personally only make a discrete LDO for demonstration purposes.
Thank you for video! Could you please tell, what software was used to create the sketch for linear regulator work explaination (from 4:20)? It has some vintage vibes.
Thanks for watching! I used draw.io (free, online).
@@PhilsLab Thank you very much!
👍🙏❤
Hi! Phil.
May I know when your 'Advanced Hardware Design Course' is coming out?
Hey, I have three lessons left to upload (out of twelve) - goal is to release this or next week! Will make a video once the course is live.
@@PhilsLab I'll hold my breath until the lecture is released :)
I have a circuit with analog sections, an mcu and adc.
Main voltage is +/-15v, already regulated and stable but i need 5v and 3.3v .
I need this to be low noise mainly due to the adc.
I need the 5v to be exactly 5v.
Can anyone give me advice on what parts to use?I imagine I need an accurate 5v regulator going into an 3.3v ldo.
Is there any reason to use an 5v ldo since my main voltage is +/-15v ?
Using a 7805 i have noticed that the 5v is not accurate and seems to vary from 4.8v to 5.2.
Any thoughts.
I have used LDO regulators in the past, one problem i have had is output oscilation in some case this was solved using a residtor in series with an output capacitor or a high ESR capacitor (tantalum or electrolitic).
Does anyone know of any other solution to reduce output oscillations?
Generally if an LDO can accept ceramics you can use those. Otherwise, higher ESR capacitors or extra series resistance is a good method
What is the difference between LDO and DC-DC (buck / boost) power supply ? the DC-DC can deliver much higher currents and is much more efficient , so why not always chose the DC-DC option ? its just because LDO takes less space and BOM ?
LDO has no switching noise. More like just a constant smooth DC.
After your demostration, it seems that the AD should be much better than KiCAD... sad...