“With the increasing demand for transmission speed and power in smartphones and notebook computers, the USB-C interface has replaced micro USB as the most popular standard interface today. TDK has developed a series of miniaturized high-performance TVS diodes for ESD protection. This product was designed with future growth in data and energy transmission requirements in mind.
With the increasing demand for transmission speed and power in smartphones and notebook computers, the USB-C interface has replaced micro USB as the most popular standard interface today. TDK has developed a series of miniaturized high-performance TVS diodes for ESD protection. This product was designed with future growth in data and energy transmission requirements in mind.
In addition to data rates up to 40 Gbps, it is also possible to transmit up to 100 W of power via USB-C for fast charging. In addition to the 8 pins for high-speed data transmission, USB-C also has 4 low-speed pins that comply with the USB 2.0 standard, as well as connections for energy transmission and auxiliary buses. Figure 1 shows the assignment of a typical USB-C interface.
Figure 1: The pin assignment of USB-C. Orange: high-speed bus, green: low-speed bus (USB 2.0, blue:
It is used for energy transfer for fast charging, with power levels up to 100 W. )
Since USB-C needs to be suitable for various data rates and voltages, different ESD components are needed to provide adequate protection. USB-C requires up to 20 TVS diodes with different characteristics, which are related to the operating voltage and capacitance requirements at the corresponding data rate. Due to its 400 x 200 µm2 compact design, less than 100 µm insertion height, and high performance, this series stands out from the competition. Due to TDK’s internal design and process capabilities, it can also provide solutions to meet customer specific needs.
TVS diodes with very low capacitance for high-speed ports
The parasitic capacitance in the entire system must be kept extremely low in order to maintain the transmission rate of 20 Gbps and higher (Tx and Rx in Figure 1), and the data integrity is not affected. TDK has specially developed two new TVS diodes with high-speed data pins, which have extremely low capacitance. The capacitance of B74121 at 1 MHz is only 0.68 pF, while B74111 achieves a lower 0.48 pF. Both types are designed for operating voltages of 3.3 V and ESD protection up to 15 kV, and provide extremely low clamping voltages of less than 4 V under an ITLP of 8 A.
TDK even developed two TVS diodes for the D+ and D- data lines of the USB-C port. These capacitors are 0.55 pF or 0.43 pF and are designed for 5.5 V operating voltages. The clamping voltage is lower than 4.0 V under an ITLP of 8 A. Their ESD strength is also as high as 15 kV.
When transferring energy to the VBUS (CC SBU) pin through the USB-C port, it is necessary to design a TVS diode for higher voltage. TDK has also developed two new types of TVS, which support voltages up to 20 V, clamp voltages from 7.2 V to 26 V, and ESD up to 15 kV.
As shown in the figure, TDK ULC and GP series products have a lower clamping voltage than standard devices.
Miniaturization meets compact design needs
Since up to 20 TVS diodes are required and they need to be close to the USB port, their size is very important. The footprint of the standard WLCSP 0201 component is 600 x 300 µm2 and the insertion height is 150 µm. TDK has greatly reduced the size while ensuring the robustness of the TVS. Compared with the standard size, TDK WLCSP 01005-SL is only 400 x 200 µm2, the area is reduced by almost half, and the insertion height is also reduced to 100 µm. In the latest generation of WLCSP 01005-USL (Ultra Fine Line), the insertion height is almost half of the standard series, only 75 µm.
Figure 2: TDK provides a wide range of TVS diode selection reference for ESD protection of various pins on the USB-C port.
In addition to excellent electrical characteristics and high ruggedness, they also have features such as miniaturization.
In addition to expanding TVS diodes, TDK also offers a wide range of multilayer varistor products, customers can select according to specific applications. For example, CeraDiode® is also an excellent protection component. TDK is a one-stop supplier of ESD protection products with a wide variety of products and can provide tailor-made solutions for existing and future applications.