DRV3255-Q1: DRV3255

ming zhao

Prodigy 20 points

Part Number: DRV3255-Q1

Hi, Team

I can't understand how dose the charge pump work.

Where is the else charge loop to boost the VBST-SH? Where is the charge current going from SHx pin?

over 1 year ago

0 Adam Sidelsky over 1 year ago

TI__Guru 59510 points

Ming,

It is easier to understand once you add the output bridge FETs from SHx to GND and from DHCP to SHx.

From the datasheet: "With the CBST capacitor connected to BSTx and the SHx pins, the CBST capacitor charge is refreshed every switching cycle when SHx transitions to ground."

The datasheet describes the charge pump and BST circuit in detail, please check with your FAE if you need a copy of the datasheet.

Regards,

-Adam

0 ming zhao over 1 year ago in reply to Adam Sidelsky

Prodigy 20 points

Adam,

I understood how dose the booststrap diode work.

Could the charge pump work properly without the output bridge FETs? I can not see the full circuits for charge pump.

Regards,

-Ming

0 Adam Sidelsky over 1 year ago in reply to ming zhao

TI__Guru 59510 points

Ming,

Yes the charge pump works without the output bridge FETs.

Regards,

-Adam

Motor drivers

Motor drivers forum

DRV3255-Q1: DRV3255