DRV8714-Q1: How to diagnostic output short to gnd / short to battery fault, when output on.

ling xinjie

Part Number: DRV8714-Q1

Hi TI

When DRV8714 output normally, and output short to gnd / short to battery, how to diagnostic this fault?(not offline diagnostic )

4 months ago

0 ling xinjie 4 months ago

Intellectual 325 points

Add more information

1. When DRV8714 output normally, I short output to GND, DRV8714 will OC protection. SOx output 2.5V（AREF=5V，CSA_DIV_1=AREF / 2）.VCP respect to PVDD is 10.5V

2. When DRV8714 output normally, I short output to BATTERY, DRV8714 will protection. SOx output 0V（AREF=5V，CSA_DIV_1=AREF / 2）.VCP respect to PVDD is -0.6V

For information 2，it seems DRV8714 all gate driver is closed. It make me confuse.

0 Shinya Morita 4 months ago in reply to ling xinjie

TI__Mastermind 31825 points

Hi,

Thank you for your questions.

This FAQ could be helpful.

(+) [FAQ] DRV8714-Q1: [FAQ] DRV8705/6-Q1, DRV8714/18-Q1 Offline diagonastic - Motor drivers forum - Motor drivers - TI E2E support forums

regards

Shinya Morita

0 ling xinjie 4 months ago in reply to Shinya Morita

Intellectual 325 points

Thanks for your reply. This doc you have sent me. It is useful for offline diagnostic . But I want to know how to diagnostic short to battery when online（drv8714 driver external MOS output）

0 Shinya Morita 4 months ago in reply to ling xinjie

TI__Mastermind 31825 points

Hi,

Thank you for your questions. Please refer datasheet page 53. 7.3.8.8 MOSFET VDS Overcurrent Protection (VDS_OCP).

When OUTPUT shorted to GND, high side FET's VDS overcurrent protection will be detected.

When OUTPUT shorted to PVDD, low side FET's VDS overcurrent protection will be detected.

regards

Shinya Morita

0 ling xinjie 4 months ago in reply to Shinya Morita

Intellectual 325 points

Thanks for your reply.

1. When DRV8714 output normally, I short output to GND, DRV8714 will OC protection. SOx output 2.5V（AREF=5V，CSA_DIV_1=AREF / 2）.VCP respect to PVDD is 10.5V. I can use VDS_STAT1 register get which VDS fault.

2. When DRV8714 output normally, I short output to BATTERY, DRV8714 will protection. SOx output 0V（AREF=5V，CSA_DIV_1=AREF / 2）.VCP respect to PVDD is -0.6V. I can NOT use VDS_STAT1 register get which VDS fault. VDS_STAT1 shows all 0x0.

For 2，it seems DRV8714 all gate driver is closed. Why these difference？ Does it meet expectations?

0 Shinya Morita 4 months ago in reply to ling xinjie

TI__Mastermind 31825 points

Hi,

Thank you for your questions. Here is my feedback.

Could you share your company name and application (e.g Seat position adjustment, slide door etc)

For 2, somehow other fault was detected probably. If read back Addr 0x00 to 0x05, you can figure out which fault was detected.

Coud you share the schematic?

regards

Shinya Morita

0 ling xinjie 4 months ago in reply to Shinya Morita

Intellectual 325 points

My company is Ponyai，application is vehicle rear trunk fan.

I still confuse, for 2, VDS_STAT1 shows all 0x0. You mean only read VDS_STAT1 is not enough for short to battery?

I upload my schematic.

DRV8714_SCH.pdf

0 Shinya Morita 4 months ago in reply to ling xinjie

TI__Mastermind 31825 points

Hi,

Thank you for your feedback. Let me add some suggestion/recommendation as attached on your schematic.

My guess is DRV detected some other error/fault before VDS protection is detected. Therefore good way for debug is to check all status registers then check whether other fault is detected or not.

If other one is detected, I can say it's protection happens before VDS protection.

240517_Ponyai_DRV8714Q1_Fan_SCH_feedback.pptx

regards

Shinya Morita

0 ling xinjie 4 months ago in reply to Shinya Morita

Intellectual 325 points

OK Tanks for your reply

I will try again.Thanks.