DRV8245-Q1: Damage issue.

Jimmy WANG

Genius 4085 points

Part Number: DRV8245-Q1

Hi team,

Could you help check why DRV8245 was damaged on this application? thanks

DC=16V by Battery

The damage condition is below

1. power up--> PWM up to 96% --> continue 10S--> PWM down to 6 --> Damage

Schematic as below

DRV8245.pdf

over 1 year ago

0 Keerthivasan Kumanan over 1 year ago

TI__Mastermind 18875 points

Hello Jimmy,

The damage might be caused by Vm pumping, so if you do run this test again can you prove the VM pin to see if the voltage gets pumped up above the allowable limit. In this case it is caused by the quick drop in the PWM duty cycle. Here is a good post on Vm pumping: (+) The art of stopping a motor – VM pumping - Industrial - Technical articles - TI E2E support forums. Can you try decreasing the PWM gradually and or try increasing the bulk capacitance on VM.

Best,

Keerthi

0 Jimmy WANG over 1 year ago in reply to Keerthivasan Kumanan

Genius 4085 points

Hi team,

The customer tests when PWM is 100% quickly down to 0% that IC is okay. but 96% down to 6% will broken. why?

The customer reply why IC can not protect by self.

0 Keerthivasan Kumanan over 1 year ago in reply to Jimmy WANG

TI__Mastermind 18875 points

Hi Jimmy,

The DRV824x and the DRV814x don't have any integrated overvoltage protection. How many units have they tried this on? Is it consistent for the 100 to 0 case and the 96 to 6 cases.

Best,

Keerthi

0 Jimmy WANG over 1 year ago in reply to Keerthivasan Kumanan

Genius 4085 points

Hi team,

The customer tested 5 times always damaged when 96% down to 6%.

0 Jacob Thompson over 1 year ago in reply to Jimmy WANG

TI__Mastermind 23431 points

Hey Jimmy,

I think the reason for this is because at 6% duty cycle, the device outputs are in a driving mode 6% of the time that can result in VM pumping, meaning VM voltage rises above VM abs max. At 0% duty cycle the device is completely in Coast mode so no VM pumping is possible.

Jimmy WANG said:
The customer reply why IC can not protect by self.

The device can protect itself from overcurrent events, but it would require external circuitry to protect from overvoltage events. Overvoltage Protection in Automotive Systems

Regards,

Jacob

Motor drivers

Motor drivers forum

DRV8245-Q1: Damage issue.