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UCC28701 and UCC28711 / Thermal protection

Ryuji
Guru 20090 points
Other Parts Discussed in Thread: UCC28070, UCC28711, UCC28701
Hello,
 
Could you please kindly let me know about below three questions for UCC28070 and UCC28071 thermal protection ?
 
----------
(1) Concerning Thermal Shutdown and NTC thermistor shutdown
Are there any difference between UCC28070 and UCC28071?
 
(2)Thermal Shutdown
Please let me know the operation of thermal shutdown.
Is this Latch or Autoretry ?
If auto retly, please let me know temperature of retly.
For example, shutdown at 165degree and retry at 150 degree.
 
(3)NTC thermistor shutdown
Please let me know the operation of NTC thermal shutdown.
Is this Latch or Autoretry ?
If auto retly, please let me know hysterisis.
For example, shutdown at 0.95V and retry at 1.2V.
----------
 
Best Regards,
Ryuji Asaka
 
  • 0
    Guru 20090 points
    Hello,
     
    Sorry UCC28070 and UCC28071  is typo.
    UCC28701 and UCC28711 is correct.
     
    Thanking you for your cooperation and looking forward to your reply soon.
     
    Best Regards,
    Ryuji  Asaka
  • 0 in reply to Ryuji
    TI__Guru* 86266 points

    Hello,

    I believe the UCC2870X and the UCC2871X device that use NTC for thermal shut down does them in a similar fashion.  There is a current forced out of the pin and if the voltage at that pin drops below a certain level it shuts down the device.  You will need to study the data sheets to find out what the current and thresholds are for the devices.

    The UCC2871X family has internal startup circuitry where the UCC2870X family requires a trickle charge startup resistor.  Also the frequency and current amplitude modulation levels are slightly different between the two families as well.

    Regards,

  • 0 in reply to Mike O'
    Guru 20090 points
    Hello Mike San,
    Thank you for your prompt reply.
    I can find the threshold voltage and current for the NTC tsd.
    But I can't understand auto retry or latch off.....
    So could you please kindly let me know it?
    And I can see the internal thermal shutdown in the datasheet page 5 protection parameter of ucc28701 EC table as 165 degree.(ucc28711 too )
    Please let me know whether is this function auto retry or latch off?
    Best regards,
    Ryuji Asaka
  • 0 in reply to Ryuji
    Guru 20090 points
    Hello Mike san,
     
    Sorry for bothering you.
    But could I have the comment please ?
    If my understanding is incorect please let me know.
     
    Best Regards,
    Ryuji Asaka