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TPS54336 - overload condition

Hirotaka Matsumoto
Guru 27585 points

Hi All,

Would you mind if we ask TPS54336?

The data sheets shows,
"Furthermore, if an output overload condition (as measured by the COMP pin voltage) has lasted for more than
the hiccup wait time which is programmed for 512 switching cycles, the device will shut down itself and restart after the hiccup time of 16384 cycles. The hiccup mode helps to reduce the device power dissipation under severe overcurrent conditions."

Switching frequency(internal switching frequency) :  Min-272[MHz]  MAX-408[MHz]

We'd like to know followings, please let me know these.

<Question1>
- min and max  time(value) which the device will shut down in case of overload(current)-
We quess that the value is  "512 switching cycles" × "Switching frequency(MAX of MIN)".
Our recognition is correct, or not?

<Question2>
- min and max time(value) which the device will restart after overload(current)-
The datasheet shows the hiccup time of 16384 cycles, and these cycles are not releated "Switching frequency".
So, please let me know this min and max time.

Kind regards,

Hirotaka Matsumoto 

  • 0
    TI__Guru**** 191445 points

    Both of the time factors are related to the switching time.  Each switching cycle is 1/Fsw = 1/340k = 2.94 usec.  If the overload condition lasts for 512 switching cycles (1.5 msec typical) then the device will shut down temporarily and restart after 16384 switching cycles (48.2 msec typical).

  • 0 in reply to JohnTucker
    Guru 27585 points

    Hello John san,

    Thank you for your reply!
    We got  that both of the time factors are related to the switching time.

    We'd like to confirm to calculate the value of Max and Min as like followings;

    <Min and Max vaule of each contents>
    In case of Min Switching Frequnecy : 1/272k = 3.68 usec  
    In case of Max Switching Frequnecy : 1/408k = 2.45 usec  

    - min and max  time(value) which the device will shut down in case of overload(current)-
    -512 × 3.68usec = 1.88msec
    -512 × 2.45usec = 1.25msec

    - min and max time(value) which the device will restart after overload(current)-
    -16384 × 3.68usec = 60.3msec
    -16384 × 2.45usec = 40.1msec

    Kind regards,

    Hirotaka Matsumoto