BOOSTXL-DRV8320RS: Ringing and Miller effect on DRV8320RS

Lin Danny

Part Number: BOOSTXL-DRV8320RS
Other Parts Discussed in Thread: DRV8320

Hi Community,

I had some questions when I tried "is05_motor_id.c" of DRV8320RS application. Before I ask, I'd like to thank the community and anyone interested in this post.

Tools
- 60MHz, 1GS/s, oscilloscope
- F280049C development kit
- DRV8320RS development kit

1. When I use I2C to communicate with peripherals, sometimes the I2C goes into busy mode. I measured 3.3v at DRV8320 SW output and SDA/SCL, then I found ringing or noise. I don't know what's going on, maybe it's the MOSFET switching. Is there anyone with the same experience that we can discuss with?

I2C communication
3.3V @DRV8320 SW output

2. I measured the miller effect at high side Vgs and ringing at high side Vds, how can I reduce the effect in the circuit? I tried reducing the gate current with IDRIVEN_HS and IDRIVEN_LS reg, but the curve did not improve. Will the Miller effect and ringing effect affect the stability of 3.3v power supply?

High side, Vgs

7 months ago

0 Yara Al Shami 7 months ago

TI__Expert 5925 points

Hello Lin,

Thank you for posting to E2E! Give me a couple of days to look over your issue and give an update.

Regards,

Yara

0 Andrew Liu 7 months ago

TI__Mastermind 18916 points

Hi Lin,

Many of our team members are currently out of office for US holiday timeframe - but will be back in office by 1st week of January.

Please anticipate a delayed response & feel free to provide additional information in the meantime.
Best Regards,
Andrew

+1 Yara Al Shami 7 months ago

TI__Expert 5925 points

Hi Lin,

Sometimes ringing can be due to too high of a IDRIVE setting or maybe noise on the power supply that is influencing the output of the driver.

What is your IDRIVE setting?

What is your target rise and fall time? Also, do you know what the gate-to-drain charge on the MOSFET is?

Regards,

Yara

0 Lin Danny 7 months ago in reply to Yara Al Shami

Prodigy 10 points

Hi Yara,

Thanks for your reply. These days I optimized the measurement method, reduced the IDRIVEP/N current from 2.0/1.0A to 0.16/0.08A, and then optimized the ringing. Although the ringing still exists, I will try to optimize the circuit to reduce the ESL effect signal.

Best Regards,

Danny

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BOOSTXL-DRV8320RS: Ringing and Miller effect on DRV8320RS