A pico fuse is an ultra-miniature, high-precision overcurrent protection device designed for compact electronic circuits. Its name derives from its tiny size (often comparable to a grain of rice), making it ideal for space-constrained applications where standard fuses are too large. Below is a comprehensive breakdown of its features, functionality, and applications:
1. Core Design & Construction
Pico fuses are engineered for miniaturization without sacrificing performance, with key structural components:
Encapsulation: Typically uses epoxy resin or ceramic for the outer body. Epoxy provides excellent insulation, moisture resistance, and mechanical durability, while ceramic variants offer higher heat resistance (suitable for high-temperature environments like power supplies).
Fuse Element: A thin, precision-engineered alloy strip (e.g., tin-copper, nickel-chromium) that melts at a specific current threshold. The element's thickness and composition are calibrated to ensure consistent, reliable tripping.
Terminals: Tin-plated copper or brass leads/contact pads (surface-mount or through-hole) for strong solder adhesion, low electrical resistance, and corrosion resistance-critical for maintaining stable connections in small circuits.
2. Key Functional Traits
Overcurrent Protection Mechanism: Like all fuses, pico fuses interrupt electrical circuits when current exceeds their rated value. The fuse element heats up and melts, breaking the circuit to prevent damage to sensitive components (e.g., microchips, capacitors) or fire risks.
Action Types:
Fast-acting: Triggers within milliseconds (≤10ms) during sudden overcurrents (e.g., short circuits). Ideal for protecting delicate electronics like smartphones, wearables, or sensor modules.
Time-lag (slow-blow): Tolerates temporary inrush currents (e.g., during device startup, when motors or capacitors draw extra power) without tripping. Used in circuits with periodic current spikes, such as small motors in toys or LED drivers.
3. Electrical Specifications
Rated Current: Ranges from 50mA to 15A, covering low-power (e.g., 50mA for IoT sensors) to moderate-power (e.g., 10A for small appliances) applications.
Rated Voltage: Common values include 32V DC, 125V AC, and 250V AC-suited for low-voltage consumer electronics and household devices.
Breaking Capacity: The maximum fault current the fuse can safely interrupt (e.g., 100A at 125V AC). This ensures it stops arcing and disconnects the circuit even during severe short circuits.
Cold Resistance: Typically ≤100mΩ, minimizing voltage drop and power loss in energy-efficient devices (e.g., battery-powered gadgets).
4. Environmental & Operational Limits
Operating Temperature: Typically -55°C to +125°C, allowing use in extreme environments (e.g., automotive electronics, industrial sensors, or outdoor devices).
Humidity Resistance: Epoxy encapsulation resists moisture, making them suitable for humid environments (e.g., bathroom electronics, medical devices).
5. Safety & Compliance
Certifications: Most pico fuses meet global safety standards, such as UL (UL 248-14), VDE (EN 60127), IEC 60127, CCC, or PSE, ensuring they adhere to regional safety norms for electronics.
RoHS/REACH Compliance: Free of hazardous substances (e.g., lead, cadmium), aligning with eco-friendly manufacturing requirements for global markets.
6. Typical Applications
Pico fuses are indispensable in compact, high-density electronics, including:
Consumer gadgets: Smartphones, tablets, laptops, and wearables (e.g., smartwatches).
Medical devices: Insulin pumps, hearing aids, and portable monitors.
IoT & sensors: Wireless modules, GPS trackers, and home automation components.
Small appliances: Bluetooth speakers, electric toothbrushes, and USB chargers.
In summary, pico fuses combine miniaturization, precision, and reliability, making them the go-to overcurrent protection solution for modern compact electronics where space and performance are critical.
Audited Supplier 
){kind=link}