Design of adaptive matching true random number generator based on thermal noise

Abstract

After studying on the thermal noise model and the matching mechanism of sensitive amplifier, an adaptively matching True Random Number Generator(TRNG) design is proposed. In this design, configurable NMOS array is embedded in the sensitive amplifier firstly，and by adjusting array’s equivalent aspect ratio it could balance the working current of sensitive amplifier. Secondly, isolation unit is added at the output to achieve the matching of complementary output loads, which can improve the randomness of the sequence. Lastly, dynamic compensation algorithm is applied to achieve the adaptive calibration of TRNG, thus broadening the scope of its application. The TRNG is semi-customedly designed with TSMC 65 nm CMOS technology. The experimental results show that it can operate properly among a wide range of voltage(0.8 to 1.4 V) and temperature(-40 to 120 ℃)，the maximum output rate can rise up to 1 GHz and the average power is 0.165 pJ/bit. The randomly outputted sequence has passed the National Institute of Standards and Technology(NIST) randomness tests.

Keywords

• TRNG
• sensitive amplifier
• thermal noise
• adaptive matching