Advantages of Littelfuse eFuse Integrated Protection IC Applied in Portable Terminal Products——Analysis of the Application of Magnetic Charging Cable for Watches


Littelfuse launched the eFuse integrated protection chip LS0505EVD22 series in the third quarter. With its excellent characteristics, it was recognized by the market less than two months after its launch. It was successfully designed in the application of magnetic charging cables for portable watches and quickly obtained orders. In the fierce competition Standing out from the crowd is a milestone.

As a professional supplier of power control, circuit protection and sensor products and services for nearly a hundred years, Littelfuse electronic fuse chip applications have been relatively mature. In the low-voltage, low-current portable terminal product market, Littelfuse has been making every effort to innovate products in terms of ensuring equipment from damage, making the system work safely and reliably, and improving system robustness. Today, the design of portable devices must comply with the Type-C specification, and the USB Power Delivery (PD) must reach a maximum specification of 20 V / 5 A. Therefore, many electronic devices equipped with a Type-C interface need to support the USB-PD protocol and have a maximum output power of 100 W (20 V / 5 A).

In this application case, the user chooses the Type-C charging specification, the customized working voltage is 5 V, and the working current is 1 A. The product needs to meet the overvoltage of 20 V and overcurrent of 5 A. The line temperature must be less than the technical requirement of 50°C. Due to the diversification of Type-C charging specifications on the market, the voltage specification ranges from 5 V to 9 V, 12 V, 15 V, and 20 V. Consumers’ non-selective cross-use habits often lead to damage to electronic equipment. . Therefore, in the initial stage of product design, engineers first consider the safety and reliability of the product, satisfy the core demands of users, and make the product work normally in different application scenarios.

Advantages of Littelfuse eFuse Integrated Protection IC Applied in Portable Terminal Products——Analysis of the Application of Magnetic Charging Cable for Watches

Based on the above needs of customers, Littelfuse engineers recommended LS0505EVD22 series, one of the newly launched eFuse integrated protection chips. This product complies with the USB-PD standard and supports a maximum power of 100W, that is, when a power of 20 V / 5 A is applied to the Vbus end, it has the ability to pass this power without damage. At the same time, short-circuit Vbus to ground for 20 minutes. In the application of 5 V / 1 A, the component temperature is only 37 ° C, which is much lower than that of similar competing products of well-known brands on the market. The excellent temperature rise performance of this long-term micro-short circuit test is due to the low RdsOn, and the RdsOn of LS0505EVD22 is 50 mΩ. On the whole, a lower RdsOn can not only reduce the loss, but also take into account the design requirements and system reliability, and meet the key indicators for the evaluation of device temperature rise during the operation of portable products.

At present, the input voltage of similar products widely used in the market is 30 V, but most output voltage levels are 12 V. So this bid got burned straight away when performing the 20 V / 5 A test. The Littelfuse LS0505EVD22 series has a very high input/output withstand voltage, reaching 30 V in both directions, which is in a leading position in the industry and fully meets the basic needs set by users.

The continuous working current supported by the LS0505EVD22 series reaches 5 A, which has a greater advantage compared with the products provided by the bidding manufacturers. The higher output current provides great convenience for the upgrade of subsequent products. It is predicted that the current specification of similar applications in the future is expected to be increased to 3 A, so that the same BOM can be maintained in the system design, reducing the designer’s new product evaluation process, reducing material management, and greatly saving human resource costs.

The magnetic charging line application solution designed by Littelfuse LS0505EVD22 series, which integrates over-voltage protection, over-current protection, over-temperature protection, and short-circuit protection, finally passed the strict technical evaluation of users with excellent system performance , got the target. It is worth mentioning that the over-temperature (OT) protection function plays a vital role in system applications, and the small-sized, highly integrated DFN2X2_8L package also meets the basic requirements of such applications.

The four new eFuse integrated protection chips launched by Littelfuse all provide EVB evaluation boards, which are convenient for customers to quickly test, such as the PD maximum power test mentioned above, short-circuit temperature rise test to ground, etc., to help customers familiarize themselves with product performance and shorten development time. Help products go to market quickly.

As a first-line international brand, Littelfuse’s professional technical service engineers are distributed in various regions of the country, and they can provide customers with technical support in a timely manner and quickly respond to any questions from customers, which is also one of the key factors for obtaining this project.

Advantages of Littelfuse eFuse Integrated Protection IC Applied in Portable Terminal Products——Analysis of the Application of Magnetic Charging Cable for Watches

Typical Application Circuit

The Links:   JZRCR-NPP01B-1 6AV2124-0GC13-0AX0 DISPLAY


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