Okay here's a quick one. I just pulled a bunch of those from a motherboard. I noticed that they have low and high-side drivers with cross conduction protection. So, my question is, can they be possibly used for gate drivers in a class D design?
I can't get IR series drivers around here so don't ask. If those things i pointed above won't work, i'll have to go discrete.
I can't get IR series drivers around here so don't ask. If those things i pointed above won't work, i'll have to go discrete.
25 volts you say. Bummer, i was thinking more of +/-30 volts. But 25v is still 300 watts on a 2 ohm load (edit: it's 150 watts, i tend to forget that in dc peak=rms while in ac it's not), it wouldn't make a bad woofer amp. I can get logic level mosfets, i'll see if there are any available with a decent rdson, choices are somewhat limited. Oh wait... those 'fets on the motherboard can take 30 volts and are logic level. Guess my next topic title will be "how to turn a junked motherboard into an amplifier". 
Anyway this will be my first class D project so if it reaches anywhere near 100W it's fine.
Anyway this will be my first class D project so if it reaches anywhere near 100W it's fine.
Last edited:
25 volts you say. Bummer, i was thinking more of +/-30 volts. But 25v is still 300 watts on a 2 ohm load (edit: it's 150 watts, i tend to forget that in dc peak=rms while in ac it's not), it wouldn't make a bad woofer amp. I can get logic level mosfets, i'll see if there are any available with a decent rdson, choices are somewhat limited. Oh wait... those 'fets on the motherboard can take 30 volts and are logic level. Guess my next topic title will be "how to turn a junked motherboard into an amplifier".
Anyway this will be my first class D project so if it reaches anywhere near 100W it's fine.
Hi,
Also not suitable for audio because DT-on / DT-off (see fig.3) is a fixed digital DT. Can not adj from external R/D gate. this produce thd, especially with very low load.
This DT mode is usefull and good for power supply only.
Regards
Well, the fixed dead time would help in keeping the smoke inside of the FETs. But since my power supply is 30-0-30v i might as well do something more interesting.
Could you please tell me the basic building blocks of a discrete class D design? I can figure out how to assemble them by myself. I already have a PWM controller with feedback and everything. But what eludes me is how to actually convince the PWM to drive only one fet at a time. I saw something about inverting schmitt triggers and a NAND gate... I happen to have such chips on hand but i can't figure out what to do with them.
Could you please tell me the basic building blocks of a discrete class D design? I can figure out how to assemble them by myself.
I already have a PWM controller with feedback and everything. But what eludes me is how to actually convince the PWM to drive only one fet at a time. I saw something about inverting schmitt triggers and a NAND gate... I happen to have such chips on hand but i can't figure out what to do with them.
The PWM controller being a TL494, i read here that someone used it class D and it ended up okay. He used an IR driver however and i can't get one. So i would like to do it with discrete drivers.
I'm not that convinced on class D anyway, but i'd like to try to make a class D amp just for fun. In the long run, i want to find out whether the efficiency of class D is worth the design effort. I'm looking for 300-500W power and be it class D or class AB the amp will be powered by a switchmode supply, so is the size/weight reduction worth it? Maybe i should first build more class AB amps then make my decision.
I'm not that convinced on class D anyway, but i'd like to try to make a class D amp just for fun. In the long run, i want to find out whether the efficiency of class D is worth the design effort. I'm looking for 300-500W power and be it class D or class AB the amp will be powered by a switchmode supply, so is the size/weight reduction worth it? Maybe i should first build more class AB amps then make my decision.
Last edited:
try www.tme.eu\ro or ro.farnell.com/ and you will find almost anithing you want. especialy goodies from IR.
best regards,
Savu Silviu
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.