• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 1370 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM3406HV-Q1 / input , output protection

Ryuji
Guru 20090 points

Hello,

There is the output protection and input protection schematics example in the datasheet.
Are there any recommended parts of D2 and Z1 on the output open circuit protection and TVS  on the Typical input protection?


 

For output, Vf is about 1.65 to 4V, ILED is about 1.5A.
For input , specifications are the following.
VIN = 6V (cold-crank)
VIN = 9V to 16V (nominal)
VIN = 28V (2 minutes, double battery jump start )
VIN = 40V (300 ms, load-dump)

Best Regards,
Ryuji Asaka

  • 0
    TI__Guru 50190 points

    HI Asaka-san,

    The reason D2 is suggested is in the event and LED breaks open and there is no output capacitor, this would help to absorb the built up energy in L1 back to Vin. So this has to be sized to handle your peak inductor current. The more critical piece of protection is Z1, Here the current should be rated  to be able to continuously handle IRZ + IRSNS + ICS. Please note that the Maximum RZ recommended is 1K. The smaller the RZ, the lower the impact on LED current accuracy. So Z1 should be rated for the worst case load-dump and the total current.

    I hope this helps.

    Regards,