Hah, MUFF & PUFF mystery. 
Is there a chance that puck gate remained charged at the moment of disassembly. With practically nonexistent gate leakage, charge would provide DS conduction for hours if not for days. I just checked with one MOSFET. After just touching gate with several V, it is happily measuring DS short circuit for hours after disconnection.
Is there a chance that puck gate remained charged at the moment of disassembly. With practically nonexistent gate leakage, charge would provide DS conduction for hours if not for days. I just checked with one MOSFET. After just touching gate with several V, it is happily measuring DS short circuit for hours after disconnection.
When the current mirror gets the minimum required current to work the overshoot in the bias current is 10% and it rises slowly.
Pa solution is very nice but having the sense resistors a bit bigger in value has a bit worse performance when the amp drives loads <4ohm. I have 3.4r impedance speakers.
The sense resistor being smaller it cooks less at higher bias currents.
Even if a bit more complicated, for my speakers this fits a bit better.
Pa solution is very nice but having the sense resistors a bit bigger in value has a bit worse performance when the amp drives loads <4ohm. I have 3.4r impedance speakers.
The sense resistor being smaller it cooks less at higher bias currents.
Even if a bit more complicated, for my speakers this fits a bit better.
I think I have something new to play with.
Recently a friend gifted me some nice and big heatsinks so now I can use these pucks safely at a bit higher power dissipation than before when I used them with the small heatsinks and they were going into thermal runaway, yes.. earlier when I said they were shorting DS and coming back to life after cooling was because I heated them too much and Rds dropped so low that it behaved like a short circuit.
I combined the sePP ops with a front end and a dc servo(to keep ~1/2 rail voltage at the amp output). It uses a single rail power supply and from simulation it can give 50w/8r or 100w/4r at low thd
I will open a dedicated thread when the pcbs will get here and I will build the amp.
I have the same lousy symbols in my schematic...sorry about this one, not much that I can do about it.
Recently a friend gifted me some nice and big heatsinks so now I can use these pucks safely at a bit higher power dissipation than before when I used them with the small heatsinks and they were going into thermal runaway, yes.. earlier when I said they were shorting DS and coming back to life after cooling was because I heated them too much and Rds dropped so low that it behaved like a short circuit.
I combined the sePP ops with a front end and a dc servo(to keep ~1/2 rail voltage at the amp output). It uses a single rail power supply and from simulation it can give 50w/8r or 100w/4r at low thd
I will open a dedicated thread when the pcbs will get here and I will build the amp.
I have the same lousy symbols in my schematic...sorry about this one, not much that I can do about it.
