Driven by smartphones and other consumer electronics, the Type-C interface is rapidly gaining popularity with its faster charging and faster data transfer, as well as higher stability and durability. Many newly released phones, laptops, and tablets feature this interface. So, what is Type-C? What makes it the most dominant interface these days?
Type-C refers to USB Type-C, an interface standard published by the USB-IF organization. Type-C is the physical form of the version number, an upgrade relative to Type-A and Type-B, which can take on the role of both HOST and SLAVER.
Type-C is now being widely used, mainly due to the following significant advantages:
1. Supporting both forward and reverse insertion
The most notable advantage of Type-C is that it allows people to get rid of the trouble of plugging in cables. Thus, the damage to the components caused by misplugging can be avoided.
Figure 1: Type-C interface pin diagram
2. Faster charging and data transfer
Type-C with USB 3.1 configuration has a theoretical data transfer speed of up to 10Gbps, which is twice as fast as USB 3.0. In terms of charging, the USB-IF recently announced a revision to the USB PD Protocol 3.1 specification that will increase the maximum power of USB Type-C from 100W (20V/5A) to 240W (48V/5A).
3. Extremely rich feature expansion
SBU1, SBU2, CC1, CC2 are signals that are not available in the traditional USB interface and can be switched between multiple functions by accessing signal level detection. For example, when the headset is inserted, the interface enters the analog audio headset accessory mode, SBU1 and SBU2 as the microphone signal transmission channels, D+ D- as the left and right vocal signal transmission channels, the 3.5mm headset connector on the phone has been gradually replaced by Typc-C interface.
Despite the many advantages of Type-C, there are also shortcomings associated. For example, due to the small distance between the gold fingers within Type-C, when a foreign object or liquid enters between the gold fingers, it turns easy to short circuit. The biggest risk is the CC and SUB which are nearest to VBUS, followed by D+ and D-. This article will focus on the ESD and EOS protection schemes for D+D- ports:
Recommended circuit protection schemes for the three application scenarios are as follows:
1. Low voltage charging scheme (charging voltage 5V)
If the forward DC withstand voltage requirement for ESD and EOS devices is greater than 6V and the device passes the Surge (8/20μs) ±25V test, WS05DUCFM is recommended; when it is required to pass the Surge ±35V test, WS05DUCMFH is recommended.
2. High voltage charging scheme (charging voltage > 5V)
ESD & EOS devices are required to have a forward DC withstand voltage greater than 15V and pass the Surge ±35V test, WS15DUCMF is recommended.
Table 1: WAYON Product Specifications
3. High voltage charging scheme (charging voltage > 5V) & audio functions integrated
In application scenarios requiring ESD and EOS devices with positive DC withstand voltage greater than 15V and passing the positive Surge 35V test, and negative DC withstand voltage greater than 3V and passing the negative Surge -35V test, WAYON's highly integrated new WS7116EQF is recommended. It features a bi-directional voltage asymmetric design that can provide high DC withstand voltage and sufficient surge protection for the D+D- port. WS7116EQF also provides low trigger voltage and low clamp voltage for the negative direction, achieving near-ideal protection.
Moreover, WS7116EQF has ±30kV electrostatic protection capability, 0.3Ω ultra-low on-resistance and 0.7pF ultra-low capacitance. The package profile stays DFN1006-2L, which greatly saves board space.
WAYON provides customers with high-performance, high-reliability ESD and EOS protection devices that meet the requirements of different applications. In addition to the D+D- product applications, there are corresponding product solutions for VBUS, CC and other Type-C interface function pins.
Figure 2: WS7116EQF in the Type-C interface application diagram
Many possible applications have been shown in the WAYON Selection Manual. For more detailed product data, visit the product center of the website and view the protection component specification table. By determining the size of components, select the operating voltage range and number of channels, and filter the functions to narrow down the range of feasible options.
