星载高速跨阻放大器电离总剂量效应研究

Impact of TID on High-Speed Operational Transimpedance Amplifier on Satellite

摘要:

为得到卫星搭载的高速跨阻运算放大器在星载环境中长时间工作后的性能变化情况,对3款增益带宽积大于1GHz的高速跨阻放大器芯片关键特征参数的电离总剂量损伤特性及变化规律进行了试验研究。辐照试验在⁶⁰Co γ射线源上采用高温加速评估的方法完成,辐照到放大器芯片上的剂量率为0.3~0.5Gy(Si)/s。分析了放大器芯片输出偏置、输出噪声和带宽等关键电参数在辐照前后及高温(85℃±6℃)退火前后的特性,讨论了引起电参数变化的机理。结果表明,经过两轮150Gy(Si)剂量辐照及高温退火后,放大器芯片的输出偏置和输出噪声水平无明显变化,时域脉冲响应正常,-3dB带宽减小了3%左右。带宽为3款高速跨阻放大器芯片的辐射敏感参数,其变化与电离辐射在SiO₂/Si界面引起正电荷建立和界面态直接相关。辐照后的芯片仍然能够满足高带宽测试情况下的需求,150Gy(Si)为电参数和功能合格的累积剂量。

Abstract:

In order to obtain the performance changes of the satellite-borne high-speed operational transimpedance amplifiers after a long period of operation in the on-board environment, experimental studies were conducted on the ionization total dose damage characteristics and change patterns of key characteristic parameters of three high-speed operational transimpedance amplifier chips with a gain bandwidth product greater than 1GHz. The irradiation tests were completed using high temperature accelerated evaluation on a ⁶⁰Co γ-ray source at a dose rate of 0.3~0.5Gy(Si)/s to the amplifier chip. The characteristics of key electrical parameters such as output bias, output noise and bandwidth of the amplifier chip before and after irradiation and before and after annealing at high temperature (85℃±6℃) were analysed after the tests, and the mechanisms causing the changes in the electrical parameters were discussed. The results show that after two rounds of 150Gy(Si) dose irradiation and high temperature annealing, the output bias and output noise level of the amplifier chip do not change significantly, the time domain impulse response was normal and the -3dB bandwidth was reduced by about 3%. Bandwidth is a radiation-sensitive parameter for the three high-speed operational transimpedance amplifier chips, and its variation is directly related to the positive charge build-up and interfacial state induced by ionising radiation at the SiO₂/Si interface. The irradiated chip is still capable of meeting the demands of high bandwidth test situations, with 150Gy(Si) being the cumulative dose for electrical parameters and functional qualification.