Rebirth of the Phoenix

[Edmond Stuart]

4 Ohms
PS: with 2 or 8 Ohms I got convergence troubles again.

 

[PHEONIX]

4 Ohms
PS: with 2 or 8 Ohms I got convergence troubles again.

Hello Edmond

Thanks, are you using Sanken output devices.

Regards
Arthur

 

[Edmond Stuart]

Yes, indeed.

 

[PHEONIX]

Hello Edmond

I will set up the same circuit and do the simulations so we can compare apples for apples , but not tonight as I am going to sleep shortly.

Regards
Arthur

 

[Edmond Stuart]

Okay, success!

 

[PHEONIX]

Clamp sims with Sanken outputs

Hello Edmond

The first graph is with -2V input 4R load PM 94 degrees @3Mhz and at 2V input 4R load PM 97 degrees @2.6MHz.

Our results are closer to one another now. Interestingly when I go to sim with an 8 ohm load the output goes hard negative -46V at the output independent of input voltage, but the simulator does not say its a convergence issue.

Regards
Arthur

 

[PHEONIX]

Are they 22r base stoppers on the outputs and yet, only 10r on the drivers?
Why did you choose that high?

Hello Andrew

I know I made a comment about this before but , these values where work in progress and I have finally settled on 22R base stopper and 100R on drivers , and this is to tame parasitics on ouput stage.

What I find with BJT ouput devices is that there is quiet a bit of component spread and the resistor values I am using are to accomodate this spread , some output devices work just fine with lower values but some have low level oscillations that need higher values to tame behaviour.

Regards
Arthur