Fast switching transistor with slow rise/fall times, why?

CataM said:

And their large leads. Also leads from the other components as well.
If you can (for the components you can), minimize the height above the PCB plane reducing the inductance of the leads.
Also, your layout has improved but is there any problem if you go to a not-so-nice-looking layout like e-design has, tightening more the components together ?

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I would rather call it ol' skool than "not-so-nice-looking". Anyway there is no problem as such to tighten it more up, but since I also expect issues with pcb design, I thought it would be more time saving to wait for the first prototype pcb, and then address all issues at that time.

Some of the highest performance designs started out looking very **broken link removed** as can be seen on the late Jim Williams's work bench at Linear Technology.

E-design said:

Some of the highest performance designs started out looking very **broken link removed** as can be seen on the late Jim Williams's work bench at Linear Technology.

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I have no problem with "ugly", but as I said, I will tighten it up on the pcb design as I feel that the present layout is "good enough" to run the tests I need. When I have satisfactory test results, I have to build some more ancillary circuitry, and then do the entire pcb layout.

But first I would like to get some correct scope shots, and after three days of constant pressure Siglent have shipped my new scope which I should receive tomorrow, only two weeks later than they promised.

And I would like to thank especially Mr. E-Design and CataM for their invaluable help, I felt in good company with experienced analog engineers and I learned a lot in the process, things they never managed to learn me in the educational system.

I have no problem with "ugly"

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Prototype designs often look ugly, because they are optimized for performance, not looks. Your initial effort should always be to try squeeze the ultimate performance out of the circuit and then see how close you can get with an actual pcb/production layout. Your prototype evaluation serves as a goal to work towards with your pcb design. Often, there will be a reduction in performance going from the "dead-bug" type layout to conventional pcb layout.

It is up to the designer to decide how much degradation will be acceptable. That is a good reason to start with the raw-copper-clad pcb prototype to see what is possible when you minimize factors that may limit performance.

E-design said:

Prototype designs often look ugly, because they are optimized for performance, not looks. Your initial effort should always be to try squeeze the ultimate performance out of the circuit and then see how close you can get with an actual pcb/production layout. Your prototype evaluation serves as a goal to work towards with your pcb design. Often, there will be a reduction in performance going from the "dead-bug" type layout to conventional pcb layout.

It is up to the designer to decide how much degradation will be acceptable. That is a good reason to start with the raw-copper-clad pcb prototype to see what is possible when you minimize factors that may limit performance.

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I agree in principle, but with the advent of smd components, you could make your prototype even tighter, ugly and fiddly with higher performance than using through-hole components, it's a matter of where you put the initial bar. For this project the pcb will be with smd, and therefore I expect the printed pcb to outperform the prototype, just my two euro cents.

In any case, I got my new scope, and here are the crisp scope shots:

CH1 Pulse CH2 Q2(base) CH3 Q4(base) CH4 Q1/Q3(base)

CH1 Pulse CH2 M1(gate) CH3 M1(drain)

For this project the pcb will be with smd, and therefore I expect the printed pcb to outperform the prototype

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In certain cases with SMD, it may be so.

Try testing with a near pure resistive load first, to establish that you can get clean waveforms and that any ringing is due to load characteristics and not circuit issues.

Enjoy your new scope!