DRV8316: If the buck regulator is unused, why does it need components?

Daisuke Higa

Part Number: DRV8316

Hi support team.

From the information posted below, it was found that the switch set by BUCK_PIS_DS at startup is connected to the VM.

https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1109701/drv8316-regarding-power-sequencing/4133946#4133946

On the other hand, the datasheet states that the circuit of the buck regulator is necessary even if the buck regulator is not used.

I recognized that the buck regulator is the source power of AVDD at startup, so I thought that the buck regulator need to configure components.

However the source power of AVDD at startup is VM, so I don't think the buck regulator is needed.

In case of the buck regulator is unused, why do I need to configure compornents.

Best regards,

Higa

over 3 years ago

0 Aaron Barrera over 3 years ago

TI__Mastermind 26046 points

Hi Higa-san,

If the buck regulator components are not used, then the device will encounter BUCK_UV and BK_FLT at powerup. By design these components are required, because those buck protections cannot be disabled. Therefore we suggest small 22 ohm resistor and 22uF capacitor to minimize BOM size and allow FB_BK to be above VBK_UVLO threshold.

Thanks,
Aaron

0 Daisuke Higa over 3 years ago in reply to Aaron Barrera

Genius 4485 points

Hi Aaron-san

Thank you for your prompt reply.

I understood very well.

Thanks.

Regards,

Higa

Motor drivers

Motor drivers forum

DRV8316: If the buck regulator is unused, why does it need components?