I put the following question in the General forum of STM32, only today I saw the specific forum for questions related to Digital Power. Anyway..
I'm builing a photovoltaic power application using the F334R8, but i'm having issues with HRTIM1, TIMERA/TIMERB output. Attached are scope outputs.
CH1 the main power switch Drain-Source voltage, CH2 is the signal comming from the STM32F334R8 HRTIMA (or B) - which drives CH1; CH3 is the output of the high voltage side of the inverter (TIMC/TIMD) and CH4 is the current through an active clamp converter - synched with CH1...
The problem is: The output from TIMA/TIMB can sometimes randomly gets higher than 100%! (as shown on CH2).
HRTIMA/B configuration seems to be correct - also i'm enabling shadow registers - and the code to extract those waveforms are running an open-loop soft-start duty increase *** only ***....
It's very weird and very random, so the question is: what should I check on the STM32 side? code? hw? power-sources?
BTW:
Code to update the TIMA/TIMB registers:
HRTIM1->sTimerxRegs[HRTIM_TIMERINDEX_TIMER_A].CMP3xR = DEF_TMRA_STATIC_MAX_PWM_CTE+i_CalcDutyA;
HRTIM1->sTimerxRegs[HRTIM_TIMERINDEX_TIMER_A].CMP1xR = DEF_TMRA_STATIC_MAX_PWM_CTE-i_CalcDutyA;
HRTIM1->sTimerxRegs[HRTIM_TIMERINDEX_TIMER_B].CMP3xR = DEF_TMRA_STATIC_MAX_PWM_CTE+i_CalcDutyB;
HRTIM1->sTimerxRegs[HRTIM_TIMERINDEX_TIMER_B].CMP1xR = DEF_TMRA_STATIC_MAX_PWM_CTE-i_CalcDutyB;
Code for the soft-start:
#define DEF_FIX_DUTY 3000
// Timer 6 de 10ms
t_TimerShort[s_timer6].habilita = 1;
if (t_TimerShort[s_timer6].habilita && t_TimerShort[s_timer6].verifica)
{ t_TimerShort[s_timer6].verifica = 0;
if (stCC_CC_Params.i16_DutyA++ >DEF_FIX_DUTY) stCC_CC_Params.i16_DutyA=DEF_FIX_DUTY;
stCC_CC_Params.i16_DutyB = stCC_CC_Params.i16_DutyA;
updateCC_CC_Duty((int16_t)stCC_CC_Params.i16_DutyA,
(int16_t)stCC_CC_Params.i16_DutyB);
}
