Microcontroller based SMPS

microcontroller based smps

Hi All,

Is it possible to implement a fully microcontroller based SMPS (any rating) with out any offchip analog PWM section?.

I have seen designs where uC is used to generate reff for a PWM IC,like 3524. And PWM from this chip is used to drive SMPS.


Thanks and Regards
Itp

avr based smps

Hi Itp,

it is possible to do so.
But you should be aware that you will

1. not achive the same regulation speed like with a analog design. For that your SMPS is stable you must achive a phaseshift of less than 125deg at unity gain frequency. With a µC you need an AD-converter, lets say 5µs conversion time. Until you can calculate the next PWM value with the AD value it takes you another 5-50µs. So the minimum time delay is 10µs. Because a µC is much too slow to calculate an IIR low pass filter this you will have to add in analog domain. So on the hole I think the maximum corner frequency of you regulation will be 20kHz.

2. If your µC just hangs once there is no security mechanism. If the PWM continues running or stops running and keeps one (pair of) switch(es) on everything will blow up.

3. the resolution of you PWM is probably not good. when LP filtering the PWM signal you will get an analog voltage. The quotient of the PWM clock frequency and the output base frequency gives a "virtual" voltage resolution. e.g. 1MHz clock and 100kHz output frequency means a resolution of 10 steps or 3,3 bits. 10MHz to 100kHz -> 100 steps or 6,6bits. 100MHz to 100kHz means 1000 steps or 9.9bits resolution.



May be you should think that your µC should do sometimes more than just controlling the feedbackloop.

My suggestion is, make an analog SMPS because of speed and relyability reasons and control the required value with a DA converter.

-aOxOmOx

microcontroller in smps

Hi,

I have seen an article on this topic on EDN.
www.reed-electronics.com/ednmag/article/CA265492?text=pic16c781&stt=000


I to wish to know that anybody has used this chip.
Regards
Itp

pic based smps

Hi all,

I have found a related article on Atmel website " AVR based constant current supply". Hope it may be usefull to somebody.
http://www.atmel.com/dyn/resources/prod_documents/current_supply.pdf

Regards
Itp

+download +silabs +si8250

What is the motivation to build an SMPS using microcontroller? Anything specific? Frankly, the PWM controllers for SMPS are so inexpensive now and give the ideal performance.

Aoxomox is correct in pointing out the problem with corner frequency. The only way out is to use an extremely fast A/D converter and a super duper uC which can handle the PWM at blazing speed.

Keep in mind that the conducted emissions from SMPS is critical. I am concerned that with a digital design, you will have to spend extra efforts to curb conducted emissions.

Ajay

smps cu microcontroler

Hi everybody,

I want to make SMPS to control current of 16 Amp. Is there any idea how to implement it?

microcontroller smps low cost

so, what about using a microcontroller DSP (dsPIC or any crap alike) for PWM control ?

microcontroller based smps project

could you show me how to use it? I am never use DSP before. For your information, I am learning PIC microcontroller.

smps using 3524

ahmad_imran,

Sorry. That wasn't precisely an answer for your question, but a proposal for the discussion about MCUs and SMPS.

If you're gonna design a SMPS, I strongly suggest you to get the book "Switch Mode Power Supply Handbook" by Keith Billings. You can download it from:

**broken link removed**

(see that you gotta register there before downloading...)

good luck

smps ic 3524

Regnum,
I visit the website and registered. However, I still cannot download the handbook.
Anywany thanks for your help.

smps with pic microcontroller

8) microcontrollers can be used for supervisory purpose and VICOR is already using them in there new power supply range.
May be if some company develops a standalone controller with a built in DSP core and built in ADC and DAC and other functions required to control a SMPS people may start to use them. but the issue of price will come into picture people will use it only when it will be a low cost solution and is also offering much better specs than the regular PWM ic.

smps design using microcontroller

Hi All,

Silicon Labs Si8250 is a "Single-Chip, SMPS Digital Controller" . Anybody have used this uC?

Thanks and regards
Itp

Link:

https://www.silabs.com/tgwWebApp/pu...cts/Digital_Power/Digital_Power/en/Si8250.htm

pwm avr smps

Can this project be valuable for you?

**broken link removed**