Research On Single-Event-Effect Tolerance For Timing Circuit Of CMOS Image Sensor

CMOS image sensors are the main direction of the modern imaging technology.They have low cost,low power consumption and high readout speed,thus,they are usually used in industry detection,aerial photography,and consuming electronics.Besides,satellite imaging has become one of the main applications,especially in the fields of remote sensing imaging,sun sensor and space exploration.However,integrated circuits used in space applications are easily affected by the energetic particles in space.Single event effect is one of the main radiation effects,and it may cause temporary failure,or even permanent damage of the circuit.Timing circuit of the pixel sensor is mostly constructed by digital circuits.So it has great necessary to analyse the single event effects of the timing circuit.This thesis studies single event effect on timing circuit in circuit level and system level.In circuit level,a series of radiation-hardened-by-design(RHBD)memories are proposed in this paper.They are hardened by space module or timing module technology,and they can tolerant double-node-upset.Standard library are set up based on the cells to be conveniently used by EDA tools.Because memory cells are large-scale used,so it is necessary to design RHBD memory cells.In system level,a RHBD timing circuit of the pixel sensor is designed using Verilog HDL language.A novel enable-detector cell is proposed to harden the enable signal of the pixel sensor.It uses the timing module technology.Fault injection simulation results show that this cell is single-event-effect tolerant.Layout of the timing circuit is achieved using the standard commercial 0.18?m CMOS technology.Spliced with the pixel array,a pixel sensor is tape-out and tested.Experiment results show that this chip can perform its normal exposure,and it has the right light-response.Thus the designed timing circuit can perform its normal function.Fault-injection-simulation is made out to verify the hardening ability of the designed circuit,and the results show that the circuit can achieve its radiation-tolerant function.