BQ25601D: the function of PMID

Kailun Liu

Part Number: BQ25601D

Hi team,

Could you please further explain the function of PMID? I don't why this pin is designed to connect RBFET and HSFET. It is a Digital output but connected to a capacitor?

over 2 years ago

0 Ning T over 2 years ago

TI__Guru 57781 points

Hi,

It is a typo. PMID is a power output.

Thanks,

Ning.

0 Kailun Liu over 2 years ago in reply to Ning T

TI__Expert 3123 points

Hi Ning,

Thanks for your reply. Could you please give me more detail? Did you mean that the PMID pin could be used to supply other socket?

0 Ning T over 2 years ago in reply to Kailun Liu

TI__Guru 57781 points

Hi,

When valid VBUS is applied. Q1 (RBFET) turns on, so PMID is short to VBUS generally. That's why PMID is also the power input for the charger.

Thanks,

Ning.

0 Kailun Liu over 2 years ago in reply to Ning T

TI__Expert 3123 points

Hi Ning,

So the PMID is just used to show the voltage of VBUS?

0 Ning T over 2 years ago in reply to Kailun Liu

TI__Guru 57781 points

Hi,

Basically yes.

Thanks,

Ning.

0 Kailun Liu over 2 years ago in reply to Ning T

TI__Expert 3123 points

Hi,

Why need to set a PIN specifically to display the value of the input voltage?

Thanks!

+1 Ning T over 2 years ago in reply to Kailun Liu

TI__Guru 57781 points

Hi,

Although both VBUS and PMID are the input to the charger, the RBFET (reverse-blocking FET) in between helps to prevent the current flowing from the load side to the input supply side (i.e. VBUS adaptor). This is explained in the e2e link below.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1251521/bq25601d-the-function-of-reverse-blocking-mosfet-rbfet

Thanks,

Ning.

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BQ25601D: the function of PMID