The R451005 is a resettable fuse, also known as a polymeric positive temperature coefficient (PPTC) device, manufactured by Littelfuse. These devices are designed to protect electronic circuits from overcurrent conditions.

Applications

• USB port protection: Safeguards USB ports on computers, laptops, and other devices.
• Power supply protection: Protects power supplies in electronic equipment from overload.
• Battery protection: Prevents damage to batteries in portable devices like smartphones and tablets.
• Motor protection: Protects small motors in appliances and toys from excessive current draw.
• General circuit protection: Used in a wide variety of electronic circuits to prevent damage from overcurrent conditions.

Features

• Resettable: Returns to its low-resistance state after the overcurrent condition is removed.
• Compact size: Allows for integration into small electronic devices.
• Low resistance: Minimizes power loss during normal operation.
• Fast tripping time: Quickly responds to overcurrent conditions.
• Wide operating temperature range: Functions reliably in a variety of environments.
• RoHS compliant: Complies with environmental regulations.

Benefits

• Overcurrent protection: Prevents damage to electronic components from excessive current.
• Circuit safety: Enhances the safety and reliability of electronic circuits.
• Reduced downtime: Minimizes equipment downtime due to overcurrent failures.
• Cost savings: Eliminates the need to replace blown fuses.
• Enhanced product reliability: Improves the overall reliability of electronic products.

Additional Details

The R451005 PPTC resettable fuse operates by increasing its resistance dramatically when an overcurrent condition occurs. This increase in resistance limits the current flow, protecting the circuit. Once the fault is removed and the power is cycled or removed and reapplied, the PPTC cools down and returns to its original low-resistance state, allowing the circuit to operate normally again. The holding current (Ihold) is the maximum current that the device can carry without tripping at a specified temperature (typically 25°C). The tripping current (Itrip) is the minimum current that will cause the device to trip at the specified temperature. The device's trip time varies depending on the magnitude of the overcurrent. The voltage rating specifies the maximum voltage the device can withstand. These devices are an essential component for protecting electronic circuits from damage and ensuring reliable operation.