DRV10987: Initial Start Operation Issue

CHO SR

Genius 3415 points

Part Number: DRV10987

Hi Team,

My customer is testing it by applying it to 40W sealing pan.

Issue status:

1. Check initial inoperative condition when power is applied.

2. Check DRIVER IC's normal output of 5VDC, 3.3VDC, and 1.8VDC. (MCU is normal operation)

3. Normal operation when the motor is pushed by hand.

4. Check abnormal behavior of more than 5EA of the 10EA board.

Bad waveform :

Good waveform :

Please find the schematic and PCB that needs to be improved.

Sechmatic_Rev0-4_Up.pdf

Gerber REV0_4.zip

over 4 years ago

0 Michael Arrant over 4 years ago

TI__Expert 3535 points

Hi Cho,

Thanks for your question. One of our team members will get back to you later today or tomorrow.

Regards,

Michael

0 Vishnu Balaraj over 4 years ago

TI__Mastermind 24415 points

Hi Cho,

Did you tune the motor by modifying the EEPROM register values in the device? If so, then can you share the tuned EEPROM register values along with the motor resistance, inductance and BEMF constant? If I understood correctly, you see the device trigger a fault when you power up the device but the fan spins fine when you push the motor by hand. If this is the case, then can you check what fault is getting triggered?

Regards,

Vishnu

0 CHO SR over 4 years ago in reply to Vishnu Balaraj

Genius 3415 points

Hi Vishnu,

I'm sorry for the delay in replying.

The customer's confirmation is delayed due to the business trip.

I'll check and update you.

0 Vishnu Balaraj over 4 years ago in reply to CHO SR

TI__Mastermind 24415 points

Hi CHO,

Sure, please check and let us know if there are any updates.

Regards,

Vishnu

0 CHO SR over 4 years ago in reply to Vishnu Balaraj

Genius 3415 points

Hi Vishnu,

I'm sorry for the late reply.

The customer was late to test EEPROM settings additionally.

Share the changed Schematic and EEPROM settings.

I will update the motor resistance, inductance, and BEMF once we get it.

ADDRESS	VALUE
0x90	0xC0BB
0x91	0x5C4B
0x92	0x8CB
0x93	0x517B
0x94	0x3BBF
0x95	0x3053
0x96	0x36A0

Schematic_210427.pdf

0 Vishnu Balaraj over 4 years ago in reply to CHO SR

TI__Mastermind 24415 points

Hi CHO,

I checked the EEPROM settings and found that Dead time is programmed to 40 ns which is considered too low. This can cause shoot through across Vcc and GND. Can you increase dead time to 400 ns and try again? You mentioned that you can spin the motor only by providing an initial push. To fix this, can you disable ISD and try again? Please share the motor parameters when available.

Regards,

Vishnu

0 CHO SR over 4 years ago in reply to Vishnu Balaraj

Genius 3415 points

Dear Vishnu,

Sorry, my mistake made a wrong 0x96 value.

Dead time is 440ns

0x96 : 0x036A

0 CHO SR over 4 years ago in reply to CHO SR

Genius 3415 points

Motor spec.

Resistance: 1.86 ±5% [Ω]

Inductance: MIN 5.58 / MAX 6.31 [mH] (Conditions: 1 kHz, 1.0 V)

BEMF : 353.28 [mV/Hz]

+1 Vishnu Balaraj over 4 years ago in reply to CHO SR

TI__Mastermind 24415 points

Hi CHO,

Thanks for sharing the details. So we are trying to solver two issues here.

1. Motor starts spinning only after pushing by hand.

2. Device triggers current limit in open loop.

To resolve issue #1, can you disable ISD and try again?

To resolve issue #2, can you further increase dead time to around 800 ns? If this doesn't work then can you increase the lead time to around 1 ms?

Regards,

Vishnu

0 Matt Hein over 4 years ago in reply to Vishnu Balaraj

TI__Mastermind 21805 points

Hello Cho,

Do you need any further help?

Thanks,

Matt

0 CHO SR over 4 years ago in reply to Matt Hein

Genius 3415 points

Hi Matt,

I'm waiting for the customer's reply.

I'll complete the case, and I'll create it again if I get additional questions.

0 Matt Hein over 4 years ago in reply to CHO SR

TI__Mastermind 21805 points

Thanks Cho!

Thanks,

Matt

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DRV10987: Initial Start Operation Issue