39. Battery Mini-Breaker for Power Tool Battery Protection

Rohit is designing a Li-ion battery pack for a cordless power tool. 

The pack uses a 5S configuration (18V nominal, 21V max charged) and can deliver up to 25A during heavy drilling. 

To protect the pack from overtemperature and overcurrent, he needs a resettable thermal cutoff (battery mini-breaker) with high current and voltage ratings. 

The device must trip at 90°C and reset automatically when the temperature drops to a safe level. 

Key requirements: 

• Activation temperature: 90°C
• Voltage rating: must cover 5S pack (max 21V)
• Current rating: ≥30A (above 25A peak to avoid nuisance tripping)
• Type: Breaker (resettable) 

The company's AVL specifies Littelfuse, so the part must be selected from Littelfuse on DigiKey. 

Help him select a suitable battery mini-breaker from Littelfuse on DigiKey.