Transistor based gate drivers don't usually have as abrupt of a turn on (and off) as a comparator based circuit (these include this TL074 "Crown" type, the 311 "QSC type" or the IR2117 based circuits. The only discrete implementations where the upper tier switches on fully that uses a discrete drivers is the Crest CA series. They only use 2 tier, and use complementary HEXFETs. It takes many in parallel to make a decent P channel switch (CA 18 uses 5 IRFP9140). The less abrupt turn on/off is mitigated by the relatively high dissipation capability in the commutator. Slower switching on the order of several uS won't hurt it.
Discrete implementations are better suited to class G, where the upper tier(s) operate linearly when the lower one hits saturation. The distortion products are considerably lower, but both tiers need to be capable of high dissipation. The overall power losses are theoretically the same, but it's split up differently.
Discrete implementations are better suited to class G, where the upper tier(s) operate linearly when the lower one hits saturation. The distortion products are considerably lower, but both tiers need to be capable of high dissipation. The overall power losses are theoretically the same, but it's split up differently.
thanks diyAudio - View Profile: wg_ski for the fast reply.
then i will have to stick with tlo74 way, because it is easily available but i will use two tl072 for three tier one for upper rai and another for lower rail. by the way can smd op amp 4550 work ?? there are many being sold
i am going to use the below scheme by waso
then i will have to stick with tlo74 way, because it is easily available but i will use two tl072 for three tier one for upper rai and another for lower rail. by the way can smd op amp 4550 work ?? there are many being sold
i am going to use the below scheme by waso
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If you're not going to use true comparators, the right op amp to use is the TL072/4. Or LF353/347, basically the same thing. Slew rate is high enough to make sure the FET can get full gate voltage in under 1 us, and you can drive them outside their rails without killing them. This will happen - maybe not in "normal" operation, but in abuse, square wave testing, or just driving them into slew limit - and certainly during the development phase getting the bugs out of the PCB.
thanks so much for the reply , let me stick with tlo72, but also trying to get my hands on ir2117 i saw them very cheap at alibaba
hello mr. satji ...
best regards for you and your family
sir, can you send me the attached file about your h900 because I see your design is very elegant
hi all and happy new year .
i have one question , if i want to use tl07xx as step drivers for three tier h. which is better topology to use between the two below schemes? ,
i want more of effeciency and power than sound quality . because it is for pa use
i have one question , if i want to use tl07xx as step drivers for three tier h. which is better topology to use between the two below schemes? ,
i want more of effeciency and power than sound quality . because it is for pa use
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Of course, my amp can work for PRO sound. But for subwoofers i don't see the point of using a Class H amplifier today when there is a class D. This is significantly less heated.
For full-range speakers it works nice.
For full-range speakers it works nice.
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