基于压控振荡器的真随机数发生器设计

通过对频率抖动机理的研究，提出一种基于压控振荡器（Voltage-Controlled Oscillator，VCO）的真随机数发生器（True Random Number Generator，TRNG）设计方案.该方案将电阻热噪声放大后作为VCO的控制信号使其振荡频率在中心频率附近随机抖动.VCO所产生的慢振荡信号对周期固定的快振荡信号采样生成原始随机序列，然后利用后处理电路提高序列均匀性并消除自相关性.通过热噪声发生器调节VCO的中心频率可实现序列比特率和随机性之间的权衡.所提电路采用SMIC 55nm CMOS工艺设计，芯片面积0.0124mm²，比特率10Mbps，平均功率0.81mW.输出的随机序列通过NIST SP 800-22测试.

Design of True Random Number Generator Based on VCO

After studies on the frequency jitter mechanism,a design of true random number generator(TRNG)based on voltage-controlled oscillator(VCO)is proposed.The scheme amplified the thermal noise of resistance and took it as the control signal of VCO.Its oscillation frequency thus randomly jittered around the centre frequency.The slow oscillating signal generated by the VCO generated an raw random sequence by sampling the period-fixed fast oscillating signal,then used the post-processing circuit to improve the uniformity of sequence and to eliminate the autocorrelation.Applying the thermal noise generator to adjust the centre frequency of VCO is able to trade off the bit rate of sequence and the randomness.The proposed circuit is designed in SMIC 55nm CMOS technology with a chip area of 0.0124mm²,a bit rate of 10Mbps and an average power of 0.81mW.The output of randomly sequence passed the NIST SP 800-22 randomness test.