A nano-ampere current reference circuit and its temperature dependence control by using temperature characteristics of carrier mobilities

We have developed a nano-ampere CMOS current reference circuit that is tolerant to threshold voltage variations. This paper describes the circuit and its temperature dependence control technique for ultra-low power LSIs. Because the generated current increases with temperature, we propose a temperature dependence control architecture for a reference current by using the different temperature characteristics of “electron” and “hole” mobilities. Experiment results demonstrated that the circuit can generate a temperature compensated reference current of 9.95 nA and that the temperature dependence of the output reference current can be controlled by using the different temperature dependences of electron and hole mobilities. The temperature dependence controllability was 8.57 pA/*C·bit and its total current dissipation was 68.1 nA.