Modelling and Tuning
Modelling the controller
So this is the model of the MCU side:
Then the high voltage push-pull:
And finally the single-ended output:
So this is currently modelling the major parts and this is very close to what is seem in the real circuit.
The experience with SPICE is much better than QUCS.
A person can spend hours just trying to coax a single simulation out of QUCS having to mess with the parameters to remove the Jacobian Singulars.
Even then it could take a while to run a simulation.
SPICE, on the other hand, seems to pretty instantly work so long as there are no silly errors.
And the output from a broken simulation is quite useful in fixing bugs in the circuit.
Refining the Push-Pull Design
Need to be able to charge/discharge the gate (which is just a capacitor in the model) in 1uS.
Modelling the MCU output
pwl 0 2.5v 1u 2.5v 1u 5v 2u 5v 2u 2.5v 3u 2.5v 3u 0v 4u 0v 4u 2.5v 5u 2.5v 5u 5v 6u 5v 6u 0v 7u 0v 7u 5v 8u 5v 8u 2.5v 9u 2.5v 9u 5v 10u 5v 10u 0v 11u 0v 11u 2.5v 12u 2.5v 12u 0v 13u 0v 13u 5v 14u 5v 14u 0v 15u 0v
Trinary Controller Modelling
Creating a Useful IGBT Model
Single-Ended Output Model
...and with R59=100R:
Class-D Output Model
First pass using constant current and constant voltage base drivers
Adding fake components to class-D circuit
Improving the Model with the Fake Components
HV Direct Gate Controlled Output
LV Gate Controlled/Class-D Output
HV Gate Controlled/Class-D Output
Full Class-D Trinary
Direct Gate Drive with Controlled Current Sources
This means the battery voltage can vary to extremes without affecting the controller operation.
Single End Test