# 1812L300MR (Component) ## Description Polymeric PTC Resettable Fuse 6V 3 A Ih Surface Mount 1812 (4532 Metric), Concave The 1812L300MR is a surface-mount resettable fuse (PPTC – Polymer Positive Temperature Coefficient) designed to provide overcurrent protection in electronic circuits. When excessive current flows, the device increases its resistance sharply, limiting current to a safe level. Once the fault condition is removed and power is cycled or reduced, the device resets automatically. This component is commonly used in power supply lines, battery-powered devices, USB ports, and general consumer electronics where resettable protection is preferred over one-time fuses. Key Features Resettable overcurrent protection device (PPTC technology) Surface-mount package (1812 footprint) Automatic recovery after fault removal Low resistance in normal operation Fast trip response to overcurrent events RoHS compliant and lead-free Electrical Characteristics Hold Current (I_hold): 3.0 A Trip Current (I_trip): ~6.0 A Maximum Voltage Rating: 6 VDC Maximum Current Rating: 40 A (short duration fault) Initial Resistance (R_min / R_max): ~0.015 Ω / 0.050 Ω Trip Time: Dependent on current and ambient conditions Thermal Characteristics Operating Temperature Range: -40°C to +85°C Storage Temperature Range: -40°C to +85°C Typical Power Dissipation: Dependent on fault condition Mechanical Characteristics Package Type: Surface Mount (SMD) Package Size: 1812 (4.5 mm × 3.2 mm approx.) Termination: Nickel barrier with matte tin plating Mounting: Reflow solder compatible Applications Power supply protection USB and peripheral ports Battery pack protection Consumer electronics Industrial control circuits Compliance and Standards RoHS compliant Halogen-free (depending on manufacturer variant) UL recognized (check specific manufacturer certification) Notes Trip and hold currents are specified at 25°C; derating is required at higher temperatures Device performance depends on PCB layout and thermal environment Proper spacing and copper area improve heat dissipation and reliability #commonpartslibrary #circuitprotection #ptc #fuse ## Component Details - **Owner:** lcsc - **Created:** 11/5/2024 - **Last Updated:** 4/28/2026 - **Visibility:** Public - **Manufacturer Part Number:** 1812L300MR - **License:** https://creativecommons.org/licenses/by/4.0/ - **Part Type:** Resettable Fuses - **Manufacturer Name:** Littelfuse(美国力特) - **Product Info Url:** https://lcsc.com/product-detail/Surface-Mount-Fuses_Littelfuse_1812L300MR_Self-recovery-3A-6VDC_C127824.html - **JLCPCB Part Class:** Extended Part - **Package or Case Code:** F1812 - **LCSC Part Number:** C127824 - **Datasheet URL:** https://www.littelfuse.com/assetdocs/resettable-ptcs-1812l-datasheet?assetguid=ca5c80cb-504e-4a8a-8e74-0107520a1717 - **Used in:** 21 projects ## Distributor Pricing (qty 1) *Pricing shown for quantity 1. For price breaks and other quantities, open in Flux.* | Distributor | Unit Price (qty 1) | Stock | |------------|--------------------|-------| | [Arrow](https://www.arrow.com/en/products/1812l300mr/littelfuse?utm_currency=USD&region=europe) | $0.7135 | 3K | | [LCSC](https://www.lcsc.com/product-detail/C127824.html) | N/A | N/A | | [Mouser](https://www.mouser.com/ProductDetail/Littelfuse/1812L300MR?qs=fp%2Fo%2FcJ74okPZmQQaLnihw%3D%3D) | $1.80 | 1.3K | | [Verical](https://www.verical.com/pd/littelfuse-ptc-resettable-fuse-1812L300MR-825465?utm_currency=USD) | N/A | N/A | - **Part Type:** Circuit Protection Devices - **Manufacturer:** Littelfuse - **MPN:** 1812L300MR - **Mount Type:** Surface Mount - **Package / Case Code:** 6-R - **Pin Count:** 2 - **Compliance:** Rohs, Halogen Free, Lead Free ## Pins | Pin | Name | Type | |-----|------|------| | 1 | 1 | | | 2 | 2 | | --- *Generated from [https://www.flux.ai/lcsc/1812l300mr~a0s](https://www.flux.ai/lcsc/1812l300mr~a0s)*