Abstract: A novel true random number generator (TRNG) structure is proposed. This TRNG is on the basis of the influence of MOSFET thermal noise to channel current. In order to correct the errors introduced by process, supply voltage and temperature, this system uses coarse-grained and fine-grained tuning, and achieves dynamic balance through the finite state machine. In order to verify the effectiveness of the proposed structure, a TRNG is designed and implemented with chatered-0.18μm-1.8V process. Random bit throughput can reach up to 125 Mb/s with 1.3 mW total power consumption and 0.019 2 mm² core area. The generating random bit streams pass all NIST-SP 800-22 test.