DN2540 can be TO92 then?
Has anyone ever AB compared CCS with bootstrap (like a source follower bootstrapping the previous stage load through a capacitor)?
I'm interested in having some feedback from other people.
Do you mean SRPP?
I did that in Ultimator headphone amp output. MOSFET can be viewed as a cathode follower loaded on a tube that it bootstraps.
The TO-92 version max dissipation is only 1W and thermal resistance 132 degrees C per Watt, the TO-220 version is 15W and 29 degrees C per Watt
I mean like this one:
The first stage is a pentode (driven by its cathode through a source follower) driving the source follower of the output stage. C2 bootstraps the load of the driver pentode.
https://www.diyaudio.com/community/attachments/1738192964386-png.1414710/
I've never done it, because I bought a bunch of the TO-220 ones, but it seems like a smart idea since there are only a few volts across the bottom device.
Yes, note that SY in "His Master's Noise" used a pair of DN2540 -- but the bottom device could have been the TO-92 version as the input stage managed only 8mA.
In any event the impedance of the DMOS CCS is impressive.
Looks like the IXYS part as the top mosfet is the better choice than the DNs for modern cascoded CCS designs.
Ale does a great job here and surveys most good parts and current ratings for CCS devices.
https://www.bartola.co.uk/valves/for-sale/ccs-pcb/
Bartola ccs seems essentially identical to Pete Millet design.
For the price, the Pete Millet boards are 'goated'!
Ale does a great job here and surveys most good parts and current ratings for CCS devices.
https://www.bartola.co.uk/valves/for-sale/ccs-pcb/
Bartola ccs seems essentially identical to Pete Millet design.
For the price, the Pete Millet boards are 'goated'!
The same chip is in both TO-92 and TO-220 cases. You just get more power dissipation capability in the TO-220 size.
I've searched on the forum and found this interesting thread, even if it's on SS devices:
Post #17 by @AKSA has a brief but clear explanation.
Are there any mods needed to turn a top mosfet DN2540-based CCS into a IXYS-based one?
Something like 'his masters noise' CCS into an IXTP08N100D2 one?
Something like 'his masters noise' CCS into an IXTP08N100D2 one?
No modification required.
The cascode CCS behaviour -mainly- depends on the "lower" FET settings.
The cascode CCS behaviour -mainly- depends on the "lower" FET settings.
For "His Masters Noise" I would use a 10-turn potentiometer to get the precise resistor value for the current necessary (8mA?). Then get the closest value and solder in. In general, I don't like trimpots if there's going to be more than a few mA flowing through.