BOURNS MF-USML400-2 Resettable Fuses - PPTC 6V 4A-HD, 50A MAX
The BOURNS MF-USML400-2 is a high-performance, resettable PPTC (Polymer Positive Temperature Coefficient) fuse designed for circuit protection applications. Manufactured in China, this device offers reliable overcurrent protection with low resistance and fast trip response, making it ideal for various electronic systems.
Resettable PPTC fuse with a maximum voltage of 6V and current rating of 4A
Maximum trip current of 8A at 23°C, with hold current of 4A
Resistance at 23°C: 0.0015 Ohms (typical)
Fast trip response with maximum time to trip of 20 seconds
Suitable for thermal protection in Li-ion batteries, game consoles, PC motherboards, USB ports, mobile phones, and digital cameras
RoHS compliant and environmentally friendly
Electrical Specifications
Model
V max. Volts
I max. Amps
Ihold
Itrip
Resistance (Ohms at 23°C)
Max. Time To Trip (Seconds at 23°C)
Tripped Power Dissipation (Watts at 23°C)
MF-USML400
6
50
4.00
8.00
0.0015
20
0.8
Environmental & Mechanical Characteristics
Operating Temperature Range: -40°C to +85°C
Storage Conditions: Max +40°C / 70% RH before opening; Max +40°C / 10% RH after opening
Resistance Change after Aging: ±10% (1000 hours at 85°C)
Humidity Aging Resistance: ±15% (100 hours at 85% R.H.)
Thermal Shock Resistance: ±30% (20 cycles between -40°C and +85°C)
Vibration & Solvent Resistance: No change (MIL-STD-883C, MIL-STD-202)
ESD Classification: Class 6 (HBM)
Additional Details
Reel Packaging: 5000 pcs per reel
Compliance: RoHS, UL (File Number: E174545), R 50302873
Soldering: Reflow recommended; do not wave or hand solder
Note: Datasheet and detailed specifications available at the provided link. Users should verify device performance in their specific applications.
Important: The product is RoHS compliant, UL listed, and environmentally safe. For detailed application guidelines and legal disclaimers, please refer to the datasheet and legal links provided.
For more detailed specifications and application information, please visit the MF-USML Series Datasheet.
Disclaimer: The datasheet was not processed; please search the internet for the part number for more details.
I'm particularly impressed with how carefully the header pins are packed for the RP2350-PiZero, they arrived in perfect condition without any bent pins, which has been a persistent issue with other competitors. This attention to packaging detail really stands out.
I also received the latest A4 revision of the RP2350, which shows you maintain current inventory, that's really valuable for customers who want the most up to date components.
The delivery was quick and hassle free throughout. I'll definitely be recommending you to others!
App feedback: The discounts offered through the app are a nice bonus, but the component search function could be improved to match the ease of use on the website version. The rest of the app functions work well.
{"id":10019817488701,"title":"MF-USML400-2","handle":"mf-usml400-2","description":"\u003ch3\u003eBOURNS MF-USML400-2 Resettable Fuses - PPTC 6V 4A-HD, 50A MAX\u003c\/h3\u003e\n\u003cp\u003eThe BOURNS MF-USML400-2 is a high-performance, resettable PPTC (Polymer Positive Temperature Coefficient) fuse designed for circuit protection applications. Manufactured in China, this device offers reliable overcurrent protection with low resistance and fast trip response, making it ideal for various electronic systems.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e MF-USML400-2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e BOURNS\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin:\u003c\/strong\u003e CN\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit of Measure:\u003c\/strong\u003e EA\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eECCN:\u003c\/strong\u003e EAR99\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Type:\u003c\/strong\u003e REEL\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDatasheet:\u003c\/strong\u003e \u003ca href=\"https:\/\/www.waldomapac.com\/productfiles\/mf-bo\/mfusml.pdf\" target=\"_blank\"\u003eMF-USML Series Datasheet\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eProduct Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eResettable PPTC fuse with a maximum voltage of 6V and current rating of 4A\u003c\/li\u003e\n\u003cli\u003eMaximum trip current of 8A at 23°C, with hold current of 4A\u003c\/li\u003e\n\u003cli\u003eResistance at 23°C: 0.0015 Ohms (typical)\u003c\/li\u003e\n\u003cli\u003eFast trip response with maximum time to trip of 20 seconds\u003c\/li\u003e\n\u003cli\u003eSuitable for thermal protection in Li-ion batteries, game consoles, PC motherboards, USB ports, mobile phones, and digital cameras\u003c\/li\u003e\n\u003cli\u003eRoHS compliant and environmentally friendly\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eElectrical Specifications\u003c\/h3\u003e\n\u003ctable border=\"1\" cellpadding=\"5\" cellspacing=\"0\"\u003e\n\u003ctr\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eV max. Volts\u003c\/th\u003e\n\u003cth\u003eI max. Amps\u003c\/th\u003e\n\u003cth\u003eIhold\u003c\/th\u003e\n\u003cth\u003eItrip\u003c\/th\u003e\n\u003cth\u003eResistance (Ohms at 23°C)\u003c\/th\u003e\n\u003cth\u003eMax. Time To Trip (Seconds at 23°C)\u003c\/th\u003e\n\u003cth\u003eTripped Power Dissipation (Watts at 23°C)\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMF-USML400\u003c\/td\u003e\n\u003ctd\u003e6\u003c\/td\u003e\n\u003ctd\u003e50\u003c\/td\u003e\n\u003ctd\u003e4.00\u003c\/td\u003e\n\u003ctd\u003e8.00\u003c\/td\u003e\n\u003ctd\u003e0.0015\u003c\/td\u003e\n\u003ctd\u003e20\u003c\/td\u003e\n\u003ctd\u003e0.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch3\u003eEnvironmental \u0026amp; Mechanical Characteristics\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eOperating Temperature Range: -40°C to +85°C\u003c\/li\u003e\n\u003cli\u003eStorage Conditions: Max +40°C \/ 70% RH before opening; Max +40°C \/ 10% RH after opening\u003c\/li\u003e\n\u003cli\u003eResistance Change after Aging: ±10% (1000 hours at 85°C)\u003c\/li\u003e\n\u003cli\u003eHumidity Aging Resistance: ±15% (100 hours at 85% R.H.)\u003c\/li\u003e\n\u003cli\u003eThermal Shock Resistance: ±30% (20 cycles between -40°C and +85°C)\u003c\/li\u003e\n\u003cli\u003eVibration \u0026amp; Solvent Resistance: No change (MIL-STD-883C, MIL-STD-202)\u003c\/li\u003e\n\u003cli\u003eESD Classification: Class 6 (HBM)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eAdditional Details\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eReel Packaging: 5000 pcs per reel\u003c\/li\u003e\n\u003cli\u003eCompliance: RoHS, UL (File Number: E174545), R 50302873\u003c\/li\u003e\n\u003cli\u003eSoldering: Reflow recommended; do not wave or hand solder\u003c\/li\u003e\n\u003cli\u003eNote: Datasheet and detailed specifications available at the provided link. Users should verify device performance in their specific applications.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e The product is RoHS compliant, UL listed, and environmentally safe. For detailed application guidelines and legal disclaimers, please refer to the datasheet and legal links provided.\u003c\/p\u003e\n\u003cp\u003eFor more detailed specifications and application information, please visit the \u003ca href=\"https:\/\/www.waldomapac.com\/productfiles\/mf-bo\/mfusml.pdf\" target=\"_blank\"\u003eMF-USML Series Datasheet\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eDisclaimer: The datasheet was not processed; please search the internet for the part number for more details.\u003c\/p\u003e","published_at":"2025-08-11T17:20:34+05:30","created_at":"2025-08-11T17:20:34+05:30","vendor":"Waldom Electonics","type":"Circuit Protection","tags":["4A","50A","6V","BOURN","Circuit","IMPORT_CSV","PPTC","WLDM"],"price":3465,"price_min":3465,"price_max":3465,"available":true,"price_varies":false,"compare_at_price":null,"compare_at_price_min":0,"compare_at_price_max":0,"compare_at_price_varies":false,"variants":[{"id":50608492544317,"title":"Default Title","option1":"Default Title","option2":null,"option3":null,"sku":"MF-USML400-2","requires_shipping":true,"taxable":true,"featured_image":null,"available":true,"name":"MF-USML400-2","public_title":null,"options":["Default Title"],"price":3465,"weight":250,"compare_at_price":null,"inventory_management":"shopify","barcode":"MF-USML400-2","requires_selling_plan":false,"selling_plan_allocations":[]}],"images":["\/\/thinkrobotics.com\/cdn\/shop\/files\/MF-USML400-2_49868052_80c1b574.jpg?v=1754913038"],"featured_image":"\/\/thinkrobotics.com\/cdn\/shop\/files\/MF-USML400-2_49868052_80c1b574.jpg?v=1754913038","options":["Title"],"media":[{"alt":null,"id":45783841833277,"position":1,"preview_image":{"aspect_ratio":1.485,"height":200,"width":297,"src":"\/\/thinkrobotics.com\/cdn\/shop\/files\/MF-USML400-2_49868052_80c1b574.jpg?v=1754913038"},"aspect_ratio":1.485,"height":200,"media_type":"image","src":"\/\/thinkrobotics.com\/cdn\/shop\/files\/MF-USML400-2_49868052_80c1b574.jpg?v=1754913038","width":297}],"requires_selling_plan":false,"selling_plan_groups":[],"content":"\u003ch3\u003eBOURNS MF-USML400-2 Resettable Fuses - PPTC 6V 4A-HD, 50A MAX\u003c\/h3\u003e\n\u003cp\u003eThe BOURNS MF-USML400-2 is a high-performance, resettable PPTC (Polymer Positive Temperature Coefficient) fuse designed for circuit protection applications. Manufactured in China, this device offers reliable overcurrent protection with low resistance and fast trip response, making it ideal for various electronic systems.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e MF-USML400-2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e BOURNS\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin:\u003c\/strong\u003e CN\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit of Measure:\u003c\/strong\u003e EA\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eECCN:\u003c\/strong\u003e EAR99\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Type:\u003c\/strong\u003e REEL\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDatasheet:\u003c\/strong\u003e \u003ca href=\"https:\/\/www.waldomapac.com\/productfiles\/mf-bo\/mfusml.pdf\" target=\"_blank\"\u003eMF-USML Series Datasheet\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eProduct Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eResettable PPTC fuse with a maximum voltage of 6V and current rating of 4A\u003c\/li\u003e\n\u003cli\u003eMaximum trip current of 8A at 23°C, with hold current of 4A\u003c\/li\u003e\n\u003cli\u003eResistance at 23°C: 0.0015 Ohms (typical)\u003c\/li\u003e\n\u003cli\u003eFast trip response with maximum time to trip of 20 seconds\u003c\/li\u003e\n\u003cli\u003eSuitable for thermal protection in Li-ion batteries, game consoles, PC motherboards, USB ports, mobile phones, and digital cameras\u003c\/li\u003e\n\u003cli\u003eRoHS compliant and environmentally friendly\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eElectrical Specifications\u003c\/h3\u003e\n\u003ctable border=\"1\" cellpadding=\"5\" cellspacing=\"0\"\u003e\n\u003ctr\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eV max. Volts\u003c\/th\u003e\n\u003cth\u003eI max. Amps\u003c\/th\u003e\n\u003cth\u003eIhold\u003c\/th\u003e\n\u003cth\u003eItrip\u003c\/th\u003e\n\u003cth\u003eResistance (Ohms at 23°C)\u003c\/th\u003e\n\u003cth\u003eMax. Time To Trip (Seconds at 23°C)\u003c\/th\u003e\n\u003cth\u003eTripped Power Dissipation (Watts at 23°C)\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMF-USML400\u003c\/td\u003e\n\u003ctd\u003e6\u003c\/td\u003e\n\u003ctd\u003e50\u003c\/td\u003e\n\u003ctd\u003e4.00\u003c\/td\u003e\n\u003ctd\u003e8.00\u003c\/td\u003e\n\u003ctd\u003e0.0015\u003c\/td\u003e\n\u003ctd\u003e20\u003c\/td\u003e\n\u003ctd\u003e0.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch3\u003eEnvironmental \u0026amp; Mechanical Characteristics\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eOperating Temperature Range: -40°C to +85°C\u003c\/li\u003e\n\u003cli\u003eStorage Conditions: Max +40°C \/ 70% RH before opening; Max +40°C \/ 10% RH after opening\u003c\/li\u003e\n\u003cli\u003eResistance Change after Aging: ±10% (1000 hours at 85°C)\u003c\/li\u003e\n\u003cli\u003eHumidity Aging Resistance: ±15% (100 hours at 85% R.H.)\u003c\/li\u003e\n\u003cli\u003eThermal Shock Resistance: ±30% (20 cycles between -40°C and +85°C)\u003c\/li\u003e\n\u003cli\u003eVibration \u0026amp; Solvent Resistance: No change (MIL-STD-883C, MIL-STD-202)\u003c\/li\u003e\n\u003cli\u003eESD Classification: Class 6 (HBM)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eAdditional Details\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eReel Packaging: 5000 pcs per reel\u003c\/li\u003e\n\u003cli\u003eCompliance: RoHS, UL (File Number: E174545), R 50302873\u003c\/li\u003e\n\u003cli\u003eSoldering: Reflow recommended; do not wave or hand solder\u003c\/li\u003e\n\u003cli\u003eNote: Datasheet and detailed specifications available at the provided link. Users should verify device performance in their specific applications.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e The product is RoHS compliant, UL listed, and environmentally safe. For detailed application guidelines and legal disclaimers, please refer to the datasheet and legal links provided.\u003c\/p\u003e\n\u003cp\u003eFor more detailed specifications and application information, please visit the \u003ca href=\"https:\/\/www.waldomapac.com\/productfiles\/mf-bo\/mfusml.pdf\" target=\"_blank\"\u003eMF-USML Series Datasheet\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eDisclaimer: The datasheet was not processed; please search the internet for the part number for more details.\u003c\/p\u003e"}
