In recent years, exhibition spaces using VR equipment have gradually become popular, allowing visitors to easily experience VR content and making the exhibition more vivid. On the other hand, theme parks have also introduced VR games to increase the attraction and enrichment, which has prompted the development of VR game equipment. In the foreseeable future, more exciting VR experiences are bound to appear in various exhibitions or amusement parks. For home consoles and PC platforms, Nintendo has launched VR-based hand-made games, while Sony also uses PS5 as the platform to launch PS VR device games that support the PS series to operate the home console VR game market.
Under the thread of coronavirus (COVID-19) in this year, online meeting or collaboration have become new types of work. The goal is to improve the way people work, entertain, chat and interact. The greatest feature is that the user can see PC desktop of others which give users the feeling of being in a real meeting room. Major manufacturers such as Oculus and hTC VIVE have launched head-mounted display to support the needs. Recently, many companies have introduced VR for training purpose. For instance, there are examples for aircraft pilot training that involves VR. The advantage of VR training is that it can simulate real-world training and standardized training courses. It also can simulate crisis situation in low risk to improve crisis handling capability of employees for ensuring quality and effectiveness of training.
As mentioned above, there are many places such as theme park and home entertainment that provide VR experiences. However, most of the current head-mounted devices are connected to device with cable. Use graphic card manufacturer as an example, USB Type-C port is usually used for transmission of video signal. For example, the transmission protocol of Virtual link is to switch between DP1.4 and USB3.0 signals for application (Figure 1). When plugging in general USB 3.0 device, output is produced by USB 3.0; when VR devices are connected, the output will be switched to DP1.4. Because general head-mounted devices require sufficient moving space for consumer, so extended connection cables are needed which make display IC damaged by CDE (cable discharge event) easily during interface hot swap. Display IC in device is mostly in 7nm process currently, its anti-static capability is insufficient compare to product in the past. Therefore, display IC manufacturer often recommend its customer use TVS as necessary solution. However, in this special application, it should be noted that the work voltage of DP1.4 Tx, Rx is 3.3V that is higher than 2.2V maximum common mode voltage of USB3.0. Therefore, the work voltage of 3.3V should be used when selecting TVS to avoid latch-up risk in signal switching.
For this application, AMAZING Microelectronic Corp. suggests using AZ1143-04F array solution on Tx and Rx signal line and AZ1045-04F on CC, SBU, D+/D-. The comprehensive protection of AZ4024-01F in Vbus (Figure 2) can effectively protect Type-C interface from the threat of static electricity and provide more stable quality for VR applications.
Figure 1: Common block diagram of Type-C interface in VR products
