Physical Unclonable Functions (PUF) exploits process variation across same structure and design parameter unit circuits during the manufacturing processes to generate numerous unique

random and unclonable security keys.In this paper

a configurable resistance divider type DAC-PUF scheme is proposed

which consists of input register

resistor-string based DAC

voltage comparator and timing control module.After configuring the DAC cell by applying input challenges

the PUF circuit updates keys without physically replacement.In TSMC-LP 65nm CMOS technology

the layout occupies 72.4m87.8m with custom designing.Experimental results show that the PUF circuit possesses nice statistical characteristic of uniqueness

high randomness of 99.1% and high stability of 97.8%

both with respect to supply voltage variation from 1.08V to 1.32V

and temperature variation from -40℃ to 125℃. It can be effectively used in information security field.