Design Of A Radiation-hardened 8b/10b Codec Module

With the great development of science and technology,Chinese demand for radiation-hardened IC chips in the military and aerospace fields is becoming more and more urgent.The Interface chip is a key component of many electronic systems,and it play an increasingly prominent role in various equipment.SerDes(serializer / deserializer)is a kind of high-speed interface circuit for data transmission,which is widely used in military and civil fields.There is a large need for radiation-hardened SerDes in China,however it can not be designed independently and basically depends on import,so it is of great significance to design radiation-hardened SerDes.The main task of this project is to design a radiation-hardened 8B10 B codec which is built into the SerDes circuit.This paper first introduces the radiation environment and the methods of radiation hardening and explains the sources of radiation include space radiation and nuclear radiation,and then analyzes the three effects of radiation on semiconductor devices: Total Ionizing Dose,Dose Rate Effect and Single Event Effect and the damage mechanism of radiation on integrated circuits is briefly described.Finally,three mainstream methods for radiation hardening of semiconductor devices are introduced: radiation hardening by process,radiation hardening by design and radiation harden by shielding.Chapter 3 and 4 introduce the structure and design idea of SerDes circuit and 8B10 B codec.There are four main types of SerDes circuits: parallel clock SerDes,embedded clock SerDes,8B10 B codec SerDes and bit interleaving SerDes.After that,several main modules of SerDes circuit are introduced,including phase-locked loop,low-voltage differential signaling,clock data recovery and serial-parallel conversion and the purpose and principle of 8B10 B encoding and decoding are analyzed in detail.Then the article shows the schematic circuit diagram of the 8B10 B codec and introduces the port meaning of each module and the design method of the 8B10 B codec.Finally,simulate results of the 8B10 B encoder and decoder are given.Radiation hardening by design(RHBD)is an important part of radiation-hardened technology.For the basic logic gate in the codec circuit,the radiation-hardened design composed of the strengthening pull-up and pull-down network and error correction module is adopted.As for the register,we use the double DICE structure.And the 8B10 B codec circuit is also verified by simulation after radiation hardening.At the same time,in order to achieve better radiation-hardened effect,the layout of the circuit adopts the ring gate and guard ring,which can reduce the impact of the Total Ionizing Dose and Single Event Effect.The main significance of this project is to integrate the radiation-hardened design into the 8B10 B codec,which not only completes the function of 8B10 B codec circuit,but also has the ability to reduce the hazards of space radiation.