一种基于比较器共模模式的真随机数发生器设计方案

A Design of True Random Number Generator based on Common-mode Operating Mode of Comparator

通过对比较器共模工作模式和热噪声模型的研究,本文提出了一种可自适应匹配的真随机数发生器(TRNG)设计方案.该方案利用CMOS开关将热噪声反相器环形连接,实现输出电压收敛并保持在亚稳态电位.亚稳态下反相器输出节点热噪声与共模模式下比较器热噪声相叠加,由灵敏放大器转化为逻辑1或逻辑0,再经采样生成随机序列.反馈单元根据输出序列的偏向性对灵敏放大器进行自适应调节实现校准功能.所设计的电路采用SMIC 55nm CMOS工艺实现,仿真结果表明TRNG在5个工艺角下(tt,ss,ff,sf,fs)均能正常工作,最大输出速率可达1GHz,能耗为0.426pJ/bit.输出的随机序列通过NIST-SP 800-22测试.

By studying the common-mode operating mode of comparator and the thermal noise model,a design scheme of true random number generator(TRNG)with adaptive matching is proposed.In this scheme,the thermal noise inverter is connected via a CMOS switch to form a loop so that the output voltage converges and remains at the metastable potential.The thermal noise at the output node of inverter in the metastable state is superimposed by the thermal noise of the comparator in the common-mode mode and is concerted into logic 1 or logic 0 by the sense amplifier,and then generates a random sequence by sampling.According to the bias of the output sequence,the feedback unit adaptively adjusts the sense amplifier to achieve the calibration function.The proposed circuit is implemented in SMIC 55 nm CMOS process.The simulation results show that TRNG can work normally in five process corners(tt,ss,ff,sf,fs)with a maximum output rate of 1 GHz and an average power of 0.426 pJ/bit.The output random sequence was tested with NIST-SP 800-22.