A 15-nW 14-ppm/degrees C 1.18 V startup-less bandgap-based voltage regulator

We present an ultra-low-power band-gap reference-based regulator and a unique method of generating a proportional-to-absolute-temperature (PTAT) voltage and a PTAT current. The PTAT current is used to generate a BJT complementary-to-absolute-temperature (CTAT) voltage. This CTAT voltage and PTAT voltage are added to generate a regulated output voltage in the negative feedback loop to drive the load. The output of the proposed regulator is temperature stable from -20 degrees C to 85 degrees C with a mean variation of less than 20 ppm/degrees C. The proposed technique eliminates the need for an additional start-up circuitry, which is mandatory for conventional architectures. The 1.18 V output voltage regulator, designed in a 180-nm CMOS process, has a simulated line regulation of 0.1 %/V with a power consumption of 15 nW at room temperature. The proposed regulator can drive the load from 0 to 30 mA.