A CMOS 25.3 ppm°/C bandgap voltage reference using self-cascode composite transistor

Voltage reference circuits, presented in battery-operated portable equipments, should be able to be designed using standard digital CMOS process and present low-power operation. This work presents a low-power CMOS Bandgap voltage reference that uses self-cascode composite transistors, only one resistor and none of the BJT's from the device library. The output voltage is nearly the silicon bandgap voltage and its temperature coefficient is typically 25.3 ppm/°C in the temperature range of -40 to 85°C, while consuming a supply current of 25 μA. The circuit was designed using thick oxide transistors from a 130 nm CMOS process technology and the layout area is 100 μm × 100 μm.