How to use TVS DIODES and GDTs to design RF port protection Solution
2020-08-19In recent years, with the continuous improvement of people's living standards, electronic products are widely used, and computers and networks are more and more deeply embedded in people's life and work. At the same time, lightning accidents occur frequently. Lightning is extremely destructive, with voltages up to millions of volts and instantaneous currents up to hundreds of thousands of amperes. The following are the manifestations of the destructive consequences caused by lightning strikes: ① equipment damage and casualties; ② The service life of equipment or components is reduced; ③ The transmitted or stored signals and data (analog or digital) are interfered or lost, and even the electronic equipment is temporarily paralyzed or the whole system is stopped due to malfunction.
Background：
1.Global warming, thunderstorm weather increased
2. Many RFs are placed outdoors and are vulnerable to lightning strikes
3. Transfer rates up to 1Gbps，high junction capacitance requirements
4.High surge protection of security equipment has become a trend
SOCAY's Protection Solutin and eletronics components for RF Interfaces：
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Gas Discharge Tubes(GDTs)
GDT【SC1812-90CSMD】DC Spark-over Voltage：90±20%V，Nominal Impulse Discharge Current（8/20μS）：2kA，Maximum Capacitance＜1.0pF，Minimum Insulation Resistance＞1GΩ；
GDT【SC2E5-90LSMD】DC Spark-over Voltage：90±20%V，Nominal Impulse Discharge Current（8/20μS）：5kA，Maximum Capacitance＜1.0pF，Minimum Insulation Resistance＞1GΩ；
Transient Voltage Suppressor(TVS Diodes)
TVS【ESD03V32D-LC】Vrwm：3.3V；Vb：4.0V；Vesd：8KV/25KV；Ct（f=1MHz）：0.8pF；Package: SOT-323
Application：
1. Medical devices
2. Video monitoring
3. Optical transmitter
4. Other RF equipment
The Solution Notes：
1.The solution use a GDT in the front end.It is connected in parallel between signal line and ground line to attenuate very large surge currents.
2.The TVS junction capacitance at the back end is 1.2pF, which does not affect the data transmission;
3. The package is SOD-323, which is small in size and saves cost; the residual voltage is low, which effectively protects the RF chip
4.The solution meets the surge standards such as I EC61000-4-5 and GBT17626.5
For more circuit protection solutions, please go directly to the Socay website to consult the online customer service http://www.jgmf.cn/.
