Understanding Overcurrent Protection for Data Cables

With the increasing prevalence of portable products,  the application of lithium batteries is becoming more widespread. Therefore, it is crucial to ensure the safe use of lithium batteries. Data cables used for charging are particularly susceptible to the charge and discharge of lithium batteries. It is the responsibility of every manufacturer to protect data cables from overcurrent. This week, LCSC Electronics supplier BHFUSE will help us understand overcurrent protection for data cables.

Why Overcurrent Protection Becomes Important？

Currently, wires for various interfaces have a charging current range of 20mA to 8A and a voltage range of 5V to 20V. It puts forward higher requirements for the compatibility of charging data lines because of different power sources with data lines. Due to users’ usage habits, they often use power and data cables of various specifications to charge products. On the other hand, the diameter of the power cable and ground cable in the data cable becomes thicker, which also puts forward higher requirements for the reliability of the mini charging port contact. 

If the charging port is not in good contact or foreign objects such as dust or sweat fall into it during the charging process, excessive power consumption can occur. If this power consumption exceeds the range the port can withstand, the charging port will heat up and melt. The charging port will scorch or even burn the entire product. It causes a fire in severe cases. In our daily lives, we often hear news about lithium battery products catching fire or even exploding, which poses a significant danger to consumer safety. To eliminate such hazards, provide overcurrent protection for charging and data cables. , is an urgent problem that every manufacturer needs to solve.

How Does Overvoltage Protection Device Work?

To address these issues, BHFUSE suggests using PPTC resettable fuses to safeguard data cables against overcurrent and overtemperature. Install resettable fuses on the data cable ports. If the port temperature exceeds a fixed value, the resettable fuse will activate, increasing resistance and limiting current flow. These will cool the temperature of the charging port and ensure product safety. 

In practical applications of resettable fuses, due to the data wire production process, the PCB circuit board needs to undergo reflow soldering (some may require twice reflow soldering processes), wire soldering, and high-temperature injection molding. That typically requires 3-4 rounds of high-temperature welding and injection molding. Due to the material characteristics of resettable fuses, the internal resistance of some manufacturers’ fuses may exceed the specified range after repeated exposure to high temperatures, sometimes by several or even hundreds of times. These can result in charging issues, particularly for small-size fuses in 0603, 0805, and 1206 packages.

BHFUSE has collaborated with customers to develop resettable fuses suitable for such applications. The internal resistance range can be customized based on customer requirements, and the internal resistance change rate can be low even after multiple weldings. This fuse serves in batches at Xiaomi, Huawei, and other supporting foundries and their supply chains.

BHFUSE Overcurrent Protection Models

Common models of BHFUSE overcurrent protection include the following. 

LCSC Electronics is the authorized distributor of BHFUSE. BHFUSE’S overcurrent protection resettable fuse models are available at LCSC Electronics. Established in 2012 in Shenzhen, China, LCSC’s vision is to help local engineers and enterprises purchase qualified electronic parts for samples and small production purposes. After years of unremitting efforts, LCSC has become a global distributor with an extensive selection of electronic components, with more than 4 million registered customers worldwide. And the average daily order is about 14,000. LCSC is known to customers for offering in-stock inventory for fast delivery since LCSC owns 130,000㎡ intelligent warehouses. View and select BHFUSE overcurrent protection resettable fuse models.