TPS65261-1 want to use Tracking. Formula of calculating the resistance?

For example, VOUT1 3.3V, VOUT2 1.8V, VOUT3 1.25V

Design as below:
EN2, EN3 floating; SS1 connect to a capacitor to GND
EN1 low or high controlled via external logic
Vout3 connect to SS2 via resistor divider to GND (resistor divider value implement: ss2 is 0.6V when Vout1 is 1.8V)
Vout3 connect to ss3 via resistor divider to GND (resistor divider value implement: ss3 is 0.6V when Vout1 is 1.25V)

Dear Jason Wang5,

Thank you very much for reply.
I'm sorry late for reply.

May I ask a add question?

Your Reply：
Vout3 connect to SS2 via resistor divider to GND.
Vout3 connect to SS3 via resistor divider to GND.

⇒

This connect voltage Vout3 would not be Vout1?

Best regard.
Bob Lee.

i am sorry, it is typo and correct as below:
Vout1 connect to SS2 via resistor divider to GND (resistor divider value implement: ss2 is 0.6V when Vout1 rise to(or falling to) 1.8V)
Vout1 connect to ss3 via resistor divider to GND (resistor divider value implement: ss3 is 0.6V when Vout1 rise to(or falling to) 1.25V)

Dear Jason Wang5,

Thank you very much for quick response.

Best regard.
Bob Lee.

Dear Jason Wang5,

Thank you very much for reply.

May I ask a add question?

Unless EN2,EN3 pin must be floating, Will it not be tracking?
What happen other problem?

Best regard.
Bob Lee.

hi Lee,

good question. 

in order to meet POWER UP/DOWN tracking, follow below rules:

when Power up, EN2/3 must be higher no later than EN1; when power down, EN2/3 must be lower no earlier  than Vout1 drop to 0V.

If the EN2/3 floating, the EN2/3 status can meet upon rule simply.

If you connect EN1/2/3 together, the circuit can meet POWER UP tracking, but can't meet POWER DOWN tracking.

Dear Jason Wang5,

Thank you very much for quick reply.

Is there no problem at this timing?

Power up timing：EN2,EN3（enable voltage 1.26V over）⇒ EN1.
Power down timing：EN2,EN3（disable voltage 1.1V under) ⇒ Vout1.

Best regard.
Bob Lee.

hi Lee,
Power up timing is ok.

Power down timing is incorrect.
Correct timing:
Power down timing：Vout1 disable (EN1 under 1.1V) ⇒ EN2,EN3（disable voltage 1.1V under)
(note, SS2/3 should be connect to VOUT1 via resistor dividers which mentioned in previous contents)

Dear Jason Wang5,

I'm sorry.
I mistook Power down timing.

Thank you very much for quick reply.

Best regard.
Bob Lee.