What are the protective effects of TVS diodes on ESD

What are the protective effects of TVS diodes on ESD

1. Application of Bottom Connector

The bottom connector design is widely used in mobile consumer products, and currently the main products in the market are portable products such as mobile phones, PDAs, DSC (digital cameras), and MP3. Due to the DC circuit, high capacitance devices can be selected. This port may be subject to high-energy impacts, and devices that integrate TVS diodes and overcurrent protection functions can be selected.

2. RJ-45 (10/100M Ethernet network)

The RJ-45 interface is widely used on network connected interface devices, with a typical application being a 10/100M Ethernet network.

3. Protection of video circuits

At present, the common output port designs for videos include D-SUB, DVI (28 line), SCART (19 line), and D-TERMINAL (mainly used in Japanese products). Video data lines have a high data transmission rate of up to 480Mbps, and some video data transmission rates can reach over 1G. Therefore, low capacitance LCTVS transistors should be selected. It usually involves connecting a low capacitance diode in series with a TVS diode to reduce the capacitance of the entire line (which can be lower than 3pF) and meet the requirements of high-speed circuits.

4. SIM card data line protection

SIM card data line protection has always been a key product focus of various companies, and devices designed specifically for such ports that integrate ESD (TVS)/EMI/RFI protection into one chip fully reflect the infinite integration solution of chip devices. When selecting devices for different purposes, it is necessary to avoid operating the devices near their design parameter limits. Devices with fast reaction speed and high sensitivity should also be selected based on the characteristics of the protected circuit and the potential to withstand ESD impact. This is crucial for effectively playing the role of protective devices. In addition, devices that integrate other functions should also be considered first.

5. USB protection

The ESD protection of general USB is divided into two situations: uplink and downlink.

6. Audio/Speaker Data Line Protection

In terms of audio data line protection, due to the relatively low signal rate of the audio circuit, the requirement for device capacitance is not too high, and around 100pF is acceptable. Some mobile phone designs combine headphones and microphones, while others have separate circuits. In the former case, a single channel TVS transistor can be selected, while in the latter case, if the two circuits are adjacent, a multi-channel TVS array can be selected, and only one device can complete the protection of the two circuits.

7. Keys/Switches

For button and switch circuits, the data rate of these circuits is very low, and there are no special requirements for the capacitance of the device. Even ordinary TVS arrays can handle it.