The rapid development of radio frequency integrated circuits provides a broad prospect for engineers and technicians engaged in various wireless communications.But at the same time, the design of RF circuit requires the designer to have certain practical experience and engineering design ability.The design trend of high-performance and high-reliability design of electronic products makes developers' requirements for circuit protection and electromagnetic compatibility design technology continue to increase.Electrostatic discharge is one of the most important reliability issues in integrated circuit manufacturing.With the shrinking size of integrated circuits and the rapid increase in operating frequency, the electrostatic discharge protection design for radio frequency integrated circuits is a key issue in the application of radio frequency integrated circuits under CMOS technology. Each RF port of an RF IC requires ESD protection circuitry. In this article, We shares the design of RF protection solutions for all engineers:

一、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

二、Protection Solutin and Socay Products for RF Interfaces.

1.Gas Discharge Tubes(GDTs)

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；

2.Transient Voltage Suppressor(TVS Diodes)

TVS【SE03D3D01GW】Vrwm：3.3V；Vb：4.0V；Vesd：25KV；Ct（f=1MHz）：0.8pF；Package: SOT-323

三、Application

1. Medical devices

2. Video monitoring

3. Optical transmitter

4. Other RF equipment

四、The Solution Note

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; the package is SOD-323, which is small in size and saves cost; the residual voltage is low, which effectively protects the RF chip

3.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.wanjieyouneng.cn/.