Another difficulty na pwede mo maencounter is yung problem ng MOSFET on high side switching, common sa buck at buck-boost yun.
Eto po share ko nice article kung paano pagpili ng inductor, capacitor, diode at fet na gagamitin sa buck converterhttp://powerelectronics.com/mag/606PET25.pdf
hehehe. allergic ako sa analog design, pang digital lang talaga utak ko. kung may tanong ako puede bang abusihin ka nang tanong in the future?
@glutnix_neoHow come there so many different high side drivers available from like IR or Telcom (now part of Microchip)? Do they have to be matched to the MOSFET it will be used for. What are the selection criteria? What are the typical failure modes of MOSFETs in your designs and their causes?
may power electronics ebook nga pala ako by Muhammad Rashid. anyone interested? upload ko bukas kung may interested...
Nice to know madami interested sa power electronics dito, to be honest I not much experienced on high side switching circuit, yun kasi yung iniiwasan namin sa design kasi malaking added cost kung magdadagdag ng pyesa, but there's one practical solution jan. You can use a choke and form it like a transformer where on the primary andun yung gate drive na nakaground and on secondary nakaconnect sa Gate and Source ng FET, Yun nga lang, I dont think its applicable sa stepper kasi may time na hindi continous ang pulse, magsasaturate ang core, sa SMPS OK tong technique na to.Would you like to consider using a stepper motor driver IC's? sa tingin ko mas makakatipid ka dun kasi wala ng FET yun, diretso na, L293 yata yung pwede.For the criteria of selecting a driver, I think slew rate/speed is a major factor at yung driving current na rin. Although voltage driven xa may mga FET na mataas yung g-s capacitance kaya iba-iba din driver, Low side switching I dont think magkakaproblema ka dun, pwede ka gumamit ng simple transistor buffer(for high speed use a totem pole).
I have been making prototypes of 8A rated drivers through the years but they suffer from reliability problems. Overheating isn't a problem since I use relatively over rated 25A and up MOSFET. The MOSFETs run quite cool. They MOSFET occasionaly fail on power-ON or accidental shorting of the output. I think transients cause the ratings to be exceeded and the MOSFETs suffer from catastrophic failure when this happens. Supply rail voltages range from 24V-75V.
Interesting yan work nyo sir ah,All I can say po eh, sa shorting definitely the FET will fail unless we include protection circuit na ishashut-down nya mga FETs if over current.Problems on turn-on, hindi ako maxado familiar sa turn-on sequence ng stepper, all I know eh malaki current na nadodraw nya at start up, using soft start (min duty muna) would lessen the transient, not sure lang kung kaya nya patakbuhin motor nun,hehe, On bridge circuit, one thing na pwede nating iwatchout is yung nagsasabay na naka-on mga FETs (hindi pa fully turn-off yung FET eh nagon na yung other rail), This problem is can be resolved using dead time sa alternation ng mga driving pulsesSana nakatulong po sir,?