Other Parts Discussed in Thread: DRV8305-Q1EVM, DRV8305
In the DRV8305-Q1EVM there seems to be a discrepancy with how the current levels are set. Shown at the end of this entry is the text that I have copied from the lab. Here are my points of confusion.
1) According to my calculations, the DRV8305 EVM (under the default settings) will present 3.3V to the uP when there is 33A going through the sense resistor. However the define below says 66A
2) According to the WARNING below, the IQ full scale current should be larger than the max ADC reading. In this case it is half of the max ADC reading.
My Conclusion: It appears that the values have been reversed. USER_IQ_FULL_SCALE_CURRENT_A should be 66A and USER_ADC_FULL_SCALE_CURRENT_A should be 33A.
Please let me know if this is indeed the case. If it is not please correct my faulty reasoning. Thanks.
//! \brief Defines the full scale current for the IQ variables, A
//! \brief All currents are converted into (pu) based on the ratio to this value
//! \brief WARNING: this value MUST be larger than the maximum current readings that you are expecting from the motor or the reading will roll over to 0, creating a control issue
#define USER_IQ_FULL_SCALE_CURRENT_A (33.0) // DRV8305-Q1EVM = 33.0 A
//! \brief Defines the maximum current at the AD converter
//! \brief The value that will be represented by the maximum ADC input (3.3V) and conversion (0FFFh)
//! \brief Hardware dependent, this should be based on the current sensing and scaling to the ADC input
#define USER_ADC_FULL_SCALE_CURRENT_A (66.0) // DRV8305-Q1EVM = 66.0 A
