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 0.0124mm

2

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.