12. PPTC Selection & Failures cases

Question.2

A hardware product draws 4.8A max load current.
A junior developer selects Littelfuse 16R500G PPTC (I_hold = 5.0A, I_trip = 8.5A at 25°C).
(Digikey part no- F5549CT-ND)
The product operates in 20°C to 80°C ambient.
Will this PPTC protect reliably without tripping?
Note- Refer Digikey Datasheet for reference- Click here

Yes — because 4.8A is below 5A hold current
Yes — because 4.8A is far below 8.5A trip current
Not necessarily — at high ambient, the effective hold current derates below 4.8A
No — because PPTCs cannot be used above 40°C

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