TPS63060 – About PG function and EN pin (start-up sequence)

Hi Team,

Our customer is studying about start-up sequence.

So, They would like to avoid those simultaneous power on.

(Please refer to the following.)

[Start-up sequence]

First:   Vin=4.5V to 8.6V(2cell) , Vout=5.15V , Iout=300mA (max)

Second: Vin=4.5V to 8.6V(2cell) , Vout=7.1V , Iout=1.2A (max)

However, they are concerned about contents as follows.

Could you please let me ask the following question?

And, Could you please let me know it if you have other advice?

[Question1]

Could you please let me know about input impedance of EN pin?

The pull-up resister of PG pin is 1Mohm.

(This value is mentioned in datasheet.)

Thus, They are concerned that the EN voltage lowers than the voltage that they assumed(5.15V) if it is low impedance(for example 1Mohm).

[Question2-1]

They would like to understand about PG function.

PG pin is the open drain, thus I guess that the PG output will be high impedance if the output voltage is normal.

However, according to datasheet, it is low impedance.

Which of those is correct?

[Question2-2]

I’m understanding that the PG output voltage continues high level if the output voltage is normal.

And, if the output voltage decreases or abnormal conditions of the this device, the PG output voltage will be low level, 0.4V(max).

Is my understanding correct?

Regards,

Kanemaru