1/f noise as a performance evaluation tool for light source driving circuits in space radiation environment

In this paper an approach of performance evaluation for light source driving circuits in space radiation environment is proposed. According to the working principles of light sources and the driving circuits, the ratio of signal to noise (SNR) is presented as a criterion to evaluate the driving circuits performance. Degradation mechanism of electronic components on driving circuits in space irradiation environment is discussed, and low frequency 1/f noise is refined as deterioration feature for the electronics. Hence 1/f noise is also assumed to be characteristics to predict degradation for light source driving circuits. A noise extraction method, Allan Variance, is adopted to calculate 1/f noise level and white noise level, and then SNR is obtained. A gamma ray irradiation experiment was conducted to the driving circuits whose output voltage was sampled and storaged. The 1/f noise level, white noise level and SNR were assessed with Allan Variance. Comparison is made among calculating results pre, during and post irradiation experiment. Analysis reveals that both 1/f noise level and SNR value changed significantly. And 1/f noise deterioration gives a major contribution to degradation of SNR. The mean value of sampled voltage data fluctuated slightly and white noise level increased moderately. Wherefore the 1/f noise intensity can be characterized as the feature of performance evaluation for driving circuits in space irradiation applications.