BQ77915: Changing low-side switching of BQ7791500 to High-Side switching using BQ776200

sourav kc

Part Number: BQ77915
Other Parts Discussed in Thread: BQ76200,

Tool/software:

I connected the CHG and DSG pins of the BQ7791500 to the CHG_EN and DSG_EN pins of the BQ76200. Additionally, I bypassed the MOSFETs in the BQ77915, creating an uninterrupted ground (GND) connection. I did not modify the connection of the LD pin. How should I configure that pin?

Currently, when I attempt to discharge, the charge MOSFET does not turn on.

(I tested this using bq77915_EVM and bq76200_EVM)

over 1 year ago

0 Luis H. S. over 1 year ago

TI__Mastermind 42060 points

Hello Sourav,

Due to the architecture of the BQ77915, it may not work properly with high-side FETs due to the load-detect functionality (LD pin).

There is this older E2E that showed a possible way to make it work, but again, this has not been tested from our side:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/931587/bq77915-using-high-side-control-via-charge-pump-gate-drivers

It likely would not work well using EVM's as there is no such circuit on the EVM.

Best Regards,

Luis Hernandez Salomon

Power management

Power management forum

BQ77915: Changing low-side switching of BQ7791500 to High-Side switching using BQ776200