39. Battery Mini-Breaker for Smartphone Battery Protection
1. Component Purpose
Smartphones are held against the user’s body. A lower trip temperature (77°C) provides early protection — cutting off the cell well before temperatures that could cause burns or trigger thermal runaway.
The single cell (4.2V max) requires relatively low voltage rating (≥9V provides large margin). Current rating of 6A–12A covers the 4A peak with derating while keeping the device compact.
Required: Breaker · 77°C trip · ≥9VDC · 6A–12A · Active · Littelfuse · RoHS
2. How to Find It on DigiKey
Same category. Apply these filters:
- Type → Breaker
- Rated Functioning Temperature → 77°C
- Current Rating (Amps) → 6A to 12A
- Manufacturer → Littelfuse Inc.
- Part Status → Active
Tip: Lower current rating (6A) provides better overcurrent sensitivity for a small 4A cell. Higher rating (12A) still provides overtemperature protection at 77°C but offers less overcurrent protection.
3. Key Specifications & What They Mean
| Specification | Required | Why |
|---|---|---|
| Type | Breaker | Resettable thermal cutoff. |
| Trip Temperature | 77°C | Early protection for body-contact device. |
| Voltage Rating | ≥9VDC | Single cell max 4.2V; large margin. |
| Current Rating | 6A to 12A | 4A peak + margin; compact. |
| Part Status | Active | Currently manufactured. |
| Manufacturer | Littelfuse | Company AVL. |
| RoHS | Yes | Compliance required. |
4. Selecting a Safe, Production-Ready Part
The filtered list will show matching parts. Before you pick one, check: Is it Active? Is stock available? Is the manufacturer reputable? Is a datasheet available?
Full checklist: How to Select a Safe, Production-Ready Component — EWskills Guide