BQ40Z50-R2: Manually command the DSG FET ON or OFF

user6241791

Part Number: BQ40Z50-R2
Other Parts Discussed in Thread: BQ40Z80,

Hello,

In my application,there must be a way for me to manually command the DSG FET ON or OFF,I know that the DSG and CHG FETs can be individually controlled, but i don't know the register address.can you tell me the address of the private register to control the fets individually.Just like the private register 0x4cc4 in BQ40z80.

over 5 years ago

0 Andy Liu (BMS) over 5 years ago

TI__Guru 52115 points

Let me take a look and find out which register will meet your needs.

0 user6241791 over 5 years ago in reply to Andy Liu (BMS)

Prodigy 140 points

Thanks for your help,

If you can,please tell me the register address and description of this register. I'm waiting for your reply.

0 Andy Liu (BMS) over 5 years ago in reply to user6241791

TI__Guru 52115 points

May I know where you got the screenshot of the private register for BQ40z80?

Andy

0 Andy Liu (BMS) over 5 years ago in reply to user6241791

TI__Guru 52115 points

If you really the manual control, what you can do is to set FET_EN to 0 and then you will be able to use MAC command 0x1F or 0x20 to turn on & off of the CHG or DSG FET. You can find more details on Page 95 of BQ40z50-R2 TRM.

Please note that it is not the recommended approach.

0 user6241791 over 5 years ago in reply to Andy Liu (BMS)

Prodigy 140 points

HI,Andy

I got the screenshot from e2e,link is as follows.

Title: BQ40Z80: Firmware control of CHG and DSG for system ON/OFF

https://e2e.ti.com/support/power-management/f/196/t/851739?tisearch=e2e-sitesearch&keymatch=firmware%20control%20of%20chg

0 user6241791 over 5 years ago in reply to Andy Liu (BMS)

Prodigy 140 points

I have been trying to implement a way to manually command the DSG/CHG FETON or OFF individually.The protection controlled by MCU.

I set FET_EN = 0 and disable the seal mode,i want to use the DSG/CHG_FET_TOGGLE command manually control the DSG/CHG FET ON or OFF individually.

But i found that when I set DSG_FET_TOGGLE=1, If the dsg current value above a certain threshold,the CHG will automatic turn on,even if the CHG_FET_TOGGLE=0.

This can also happen when in CHG mode.DSG_FET_TOGGLE=0,but the DSG FET turn on.

Is there any way to manually command the DSG/CHG FET ON or OFF?

0 Kang Kang over 5 years ago in reply to user6241791

TI__Mastermind 24870 points

Hello User,

In this case, it is for CHG FET protection. If the CHG FET is off, the current needs to flow through the bode diode of the CHG FET in the discharge direction. Hence, that is why you are seeing this behavior.

There is no explicit control where you turn on one without the other.

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BQ40Z50-R2: Manually command the DSG FET ON or OFF