K
Klaus Kragelund
- Jan 1, 1970
- 0
Hi
I have implemented a digital SMPS in a Cortex M3 controller. The feedback of the SMPS is done using the TL431 and opto coupler feedback.
The feedback is sampled by the ADC at 10kSa and the sampled values controls the duty-cycle of the SMPS.
It is stable, but I would like to simulate the loop in PSPice. The ADC has sample and hold along with quantiziation that affects the gain/phase. The timer generating the PWM has finite number of different dutycycles and that has a small scale effect also.
I would like to have a model both for transient and ac sweeps.
The ac sweep can be modelled by a sinc function, but how to model the quantization and PWM stage (discrete duty cycles)?
Also, for the transient simulation, the ADC can be modelled simple by a S/H. The quantization can be modelled by a floor function, and for the PWM I need another floor function and a couple of ABMs to model the PWM. But, is there a better method for this?
Thanks
Klaus
I have implemented a digital SMPS in a Cortex M3 controller. The feedback of the SMPS is done using the TL431 and opto coupler feedback.
The feedback is sampled by the ADC at 10kSa and the sampled values controls the duty-cycle of the SMPS.
It is stable, but I would like to simulate the loop in PSPice. The ADC has sample and hold along with quantiziation that affects the gain/phase. The timer generating the PWM has finite number of different dutycycles and that has a small scale effect also.
I would like to have a model both for transient and ac sweeps.
The ac sweep can be modelled by a sinc function, but how to model the quantization and PWM stage (discrete duty cycles)?
Also, for the transient simulation, the ADC can be modelled simple by a S/H. The quantization can be modelled by a floor function, and for the PWM I need another floor function and a couple of ABMs to model the PWM. But, is there a better method for this?
Thanks
Klaus