DRV8353F: Internal current amplifier architecture

CLEMENT MAGNIEN

Part Number: DRV8353F

Hello,

I am using the driver DRV8353FS. On the shunt measurement signal SP, SN, I can see spikes around 1V due to the recovery current of the Mosfet diode.

The driver breaks quite easily and I think it could be due to this spike on the current measurement pins of the driver( max datasheet is 5V transient but maybe 1V is enough to kill it)

I added a resistance + capacitor as shown on the picture below: resistance on SN since SP is also the the bottom of the low side push-pull gate driver. When adding a 150 R, I read 13 R across the resistor with a multimeter.

It's like if there was an internal resistance between SN and the ground which is not shown on the diagram. From the datasheet it's seems it's a differential amplifier with R1=10K, not totally sure if it's 10K?

Could you confirm and give me some advice to filter this spike on the shunt measurement?

Regards,

Clement

over 2 years ago

0 Eli Sorenti-Burns over 2 years ago

TI__Intellectual 1350 points

Hello Clement,

Thank you for the questions! Yes, the value of R1 is 10k. As for how to filter out the noise, that normally depends on which frequencies you wish to filter but we recommend three 1nF capacitors per shunt (between SNx and GND, between SPx and GND, and between SPx and SNx). Two 10 Ohm resistors can also be used before the capacitor and where your SNx channels connect above and below the shunts (like you did with the resistor in the first figure). If this doesn't work, try switching your MOSFETs slower or there may be too much parasitic inductance between channels in your layout. Please let me know if this solves your problem.

Best,

Eli

0 CLEMENT MAGNIEN over 2 years ago in reply to Eli Sorenti-Burns

Prodigy 80 points

Thanks, FYI the datasheet symbol is wrong, it's a P mosfet with the diode in the wrong direction, maybe it's a N mosfet ?

The driver low side burns, I think it's due to the spike on the low gate output due to the shunt parasitic inductance. Do you have any advice to protect the driver? the driver is referenced to the shunt positive side but supplied via VGLS which is reference to GND, I am thinking to add a TVS to GND on VGL.

Regards,

0 Eli Sorenti-Burns over 2 years ago in reply to CLEMENT MAGNIEN

TI__Intellectual 1350 points

Hi Clement,

Thank you for the correction! Would you mind showing me your layout? I will have a better response for you at the beginning of next week after aligning with my team.

Best,

Eli

0 CLEMENT MAGNIEN over 2 years ago in reply to Eli Sorenti-Burns

Prodigy 80 points

Hi Eli,

How can I share it in a private message?

0 Eli Sorenti-Burns over 2 years ago in reply to CLEMENT MAGNIEN

TI__Intellectual 1350 points

Hi Clement,

We will reach out to you via email by the end of the week.

Best,

Eli

0 Eli Sorenti-Burns over 2 years ago in reply to Eli Sorenti-Burns

TI__Intellectual 1350 points

Hi Clement,

Thank you for your patience. Your FAE should be reaching out to you shortly via email with some documents which may help while we find a solution.

Best,

Eli

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DRV8353F: Internal current amplifier architecture