As you can see, in this position much more speed is needed. Not kHz is important, but V/us! Switching freq is not directly related to OPA speed requirements! Eg.: if you have to follow 100 kHz 0,1 V triangle wave, then uA741 (one of the oldest OPA) can be perfect, but if you have to generate 100 kHz 10 V square, then really fast OPA (or more preferably comparator) needed, othervise square becomes tapezoid. You can (should!) count the requirements: 100 kHz -> on-time=T/2=5 us. Transition time should be less then its 10% -> 0,5 us, slew rate=dU/dt=20V/0,5us=40V/us. This is the practical minimum unless you change topology. However the circuit will work even with sine wave instead of triangle, only the distortion will increase.
AnalogDevices OPAs are solve this, but if you accepted the egsistence of problem, we could recommend some better, simple, cheap solution, wich can work at higher freq as well.
Whats wrong with the 2N3906´s ?
smoother triangle from 1euro ??😕
Pafi and others, why not get yourself into the irc channel ?
smoother triangle from 1euro ??😕
Pafi and others, why not get yourself into the irc channel ?
I don't like, and I don't have time to chat.
"Whats wrong with the 2N3906´s ?"
Nothing. Just I don't understand why do you use emitter as collector, and vica versa.
"Whats wrong with the 2N3906´s ?"
Nothing. Just I don't understand why do you use emitter as collector, and vica versa.
Pafi, its a level shifter
What a setback, the opamps i thought were OP42 turned out to be useless dc opamps OP77
Apparently the best opamp i have around is TL074. 🙁
I was hoping that i could make a pwm without having to order anything for once. Bah Doh
What a setback, the opamps i thought were OP42 turned out to be useless dc opamps OP77
Apparently the best opamp i have around is TL074. 🙁
I was hoping that i could make a pwm without having to order anything for once. Bah Doh
"Pafi, its a level shifter"
Really? What a surprise! I thought it is a traffic sign! 😀
Yes, it would be a level shifter, if you were connected it well.
Really? What a surprise! I thought it is a traffic sign! 😀
Yes, it would be a level shifter, if you were connected it well.
I've seen a similar setup of level shifters where instead of R9 there's an NPN-based VBE multiplier.
Guys, stick to the topic. Next time I have to clean up people will be spending time in the bin.
Thanks mouse🙂
I have tested the triangle generator and it works fine so next step is the comparator.
I have tested the triangle generator and it works fine so next step is the comparator.
With a 1.3uS response time I would have thought it will cause noticeable distortion on high frequency signals. Wouldn't at least an LM311 (or LM319) be required?
For the last time, this is supposed to be a SUBWOOFER amplifier.
*Tekko bonks Ouroboros with a Pass class A amp.
*Tekko bonks Ouroboros with a Pass class A amp.
LM393 seems to introduce around 200ns delay in practice. Also, it's not symmetrical but somewhat edge dependent.
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