Design And Realization Of ESD Protection Based On HDMI

HDMI is a interface protocol of digital television and customer electrical product which transmit uncompressed multi-channel audio signal and high definition video signal by one single cable,as well as ensure the best quality audio and video transmission without digital to analog or analog to digital conversion.As the issuance of HDMI specification version 1.3,the max speed of HDMI digital signal transmission can reach 10.2Gbps,while the size of HDMI image chip is quite small, so it is very sensitive to ESD.As HDMI is a hot plug interface,customers often touch HDMI and result in ESD to damage or even break inside chip in the actual life.The capacitance load in high speed video signal will result in signal attenuation,ESD protection device use various ways and technique to reduce the capacitance.ESD protection device should be chosen carefully in order to reduce the capacitance.This paper mainly discusses ESD protection based on HDMI.In this paper,firstly the basic elements,physics frame,electrical characteristic and some key technique for HDMI design are introduced.Secondly ESD protection elements and techniques are analyzed.Several familiar protection components are compared.Each advantage is analyzed.Finally,TVS diode is chosen for protecting HDMI.Orientation controlled diode and polymer device are usually used in the traditional way of high speed interface protection,but these protection devices are not the best.Traditional diode could not sustain the high surge energy defined by IEC 61000-4-2.The startup voltage of polymer device is not stabilization,usually higher than 1kv,even though its capacitance is low.It means the IC which be protected must sustain at least 1kV before polymer device responses to ESD.Accordingly,transient voltage suppressor is more suitable for protecting the circuit.Then,in this paper,the performance of TVS diode has been analyzed.Then TVS diode working principle and characteristic are analyzed in detail.On this basis the TVS diode based on HDMI ESD protection SPICE parameters have been modeled. For high speed data signal transmission circuit,each parameter of transient voltage suppressor affect the signal transmission quality possibly,so element parameters should be chosen exactly to match the protection circuit and the signal transmission circuit.In the last section of this paper,based on overview of ESD protection technology, a protection circuit design implemented is proposed.Each pin of HDMI is designed respectively for protection circuit.Insertion loss of protection device is analyzed by computer simulation.The effect of ESD by setting or without setting protection devices and the feasibility of the design is proved.