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PDB Timing - How to change Time between SVPWM Firing and PDB ADC Conversion without Changing Deadtime?

Question asked by Derek Cook on Oct 22, 2018
Latest reply on Oct 31, 2018 by Derek Cook

Hello, 

 

I am wanting to change the time from when the PWM fires to when the PDB gets the phase current ADC conversions. It looks like this time is Tdeadtime/2. 

 

 

tdeadtime/2 seems too short of a time for my system. How do I increase the time between PWM firing and ADC conversion without changing the deadtime? Do I change the PDB counter? How do I change the PDB delay?

 

Is this related to the following delays in ADCS_init() for PDB?

/* Set amount of delay for the B Samples */
/* DLY0 = (0.4us / PWM_TS) * PDB0_MOD, DLY1 = (2.7us / PWM_TS) * PDB0_MOD */
KMS_PDB->CH[0].DLY[0] = 0;
KMS_PDB->CH[0].DLY[1] = 45;
KMS_PDB->CH[1].DLY[0] = 0;
KMS_PDB->CH[1].DLY[1] = 45;

 

These delays look hardcoded. Do I need to change this since my PWM freq is 4kHz and my deadtime is 3us? Is this the delay between PWM firing and ADC conversion? In the calculations which resulted in 0 and 4 - What were the PWM_Ts and PDB0_Mod? Also where did the 0.4us and 2.7us come from?

 

Thanks for the help!

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