BOOSTXL-DRV8323RH: Configuring BOOSTXL-8323RH Driver to match BOOSTXL-3PHGANINV

Hi Raghu,

Thank you for posting to the Motor drives forum. To change the GAIN/IDRIVE/VDS, you will need to refer to the DRV8323 datasheet for the voltage level needed to select the desired settings since you are using the hardware version.

Could you please provide waveform images of one each of the GHx and SHx pins? I am not entirely sure what might be causing the fault but these are a good starting point to look at. Additionally, please let me know what your supply voltage and PWM frequency is.

Best,

Davis

Hi Jackson,

Thanks for replying. 

PWM frequency  = 10KHz(varied from 4khz to 15khz but no change)

Supply Voltage = 20V but when I read the voltage from GHA/GHB/GHC it is showing 30V(image attached)

Thanks and regards

Raghu

Hi Raghu,

Both your supply voltage and GHx voltage are fine. GHx runs around 10-12V higher than your supply because it needs to turn on the gate when SHx is equal to the supply voltage. Your PWM frequency also appears to be fine.

Could you please provide an image of SHx?

Additionally, this FAQ provides more details on how to debug a fault report from a hardware variant device: https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1160331/faq-debugging-faults-with-hardware-variant-devices?tisearch=e2e-sitesearch&keymatch=debugging%2520hardware%2520variant#

Please let me know if this helps.

Best,

Davis

HI Jackson,

We have already gone through the FAQ forum. we have 47K resistor connected(R22) (gain =10).

There is no test point for SHx so we directly checked on drvic but nothing was read on that pin.

When the motor was disconnected there is no high currents but also at there is no problem with motor which means the FETs are drawing high currents. can you help me in understanding this situation.

Thanks and Regards

Raghu

Hi Raghu,

What VSEN_OCP level are you using? Can you measure the voltage across one of R6, R8, or R10 while the motor is connected when the fault occurs? Besides the fault, do you notice any damage or heating occurring in the MOSFETs? One possibility is that VSEN is set too low in the hardware, causing a fault to trip only when a motor is connected because current flows through the low side FET in this circumstance.

Best,

Davis

Hi Jackson,

Voltage across R6,R8&R10 is 0.35mV. There is no noticeable heating in MOSFETs. There's no Hardware problems as it is working with other examples.

This is mentioned in the aforementioned forum " in the DRV8323H, the sense resistor overcurrent voltage (VSEN_OCP) is fixed to 1V"  could you please tell me where can I cross check this value?

Thanks & regards

Raghu

Hi Raghu,

It looks like there is no VSEN_OCP issue then. To check, you can power the motor driver with no motor connected and apply a voltage across SPA and SNA increasing until you reach 1V to see if the fault triggers.

Is the DRV8323 showing the fault flag, or is one appearing in the software? Is there a different current limit set in the software that might be causing the shutoff?

Best,

Davis

Hi Jackson,

Current limit is 9.0A set in the software but we have set the current limit of 3A in the source power supply. we even disconnected the nFAULT pin from controller, even then this issue persists. 

Can you please tell me what factors results in drawing of high currents?

Thanks & Regards

Raghu

Hi Raghu,

There are a variety of factors that could result in high current, such as high torque on the motor and cross-conduction if both the low and high side FETs of a phase are on. But there are also a variety of other factors that might trigger a fault in the device. Can you send a current measurement when experiencing high current? If the fault is due to high current, it will either be a VDS or VSENSE overcurrent, and it does not appear you have a VSENSE overcurrent condition. There might be something else causing the fault if none of these conditions are occurring.

Best,

Davis

Hi Jackson,

Sorry for the late response. There is no load connected to motor. It is because of EPWM configuration. it is now cleared.

Can you please help or can you pull in someone who can help me with the CCXML configuration file of LAUNCHXL-F28P65X. I'm not able to find in the C2000Ware_DigitalPower_SDK_5_03_00_00 .

Thanks in advance.

Thanks and Regards,

Raghu

Hi Raghu,

Glad to hear the fault is resolved, I have reassigned this question to the C2000 team for more assistance.

Best,

Davis

Thanks Jhonson.

Raghu, 

Did you try using the exisitng ccxml file (TMS320F28P650DK9.ccxml) ? 

Best Regards

Siddharth

Hi Siddharth,

With existing CCXML file we are getting JTAG test error.

Thanks & Regards

Raghu

Raghu 

Pls share the error that you are observing. 

Open the Target Configuration file (.ccxml) in Code Composer Studio IDE. Click on the Advanced tab and select JTAG (1149.1) SWD and cJTAG are disabled

Make sure that the target configuration is set up to use JTAG in 4-pin advanced mode.

Best Regards

Siddharth