65nW CMOS temperature sensor for ultra-low power microsystems

We propose a temperature sensor using a novel process-invariant temperature sensing element and voltage to current converter for battery-operated ultra-low power micro systems. By introducing a new temperature-to-voltage sensing element that outputs only 75mV, the sensor achieves ultra-low power. The sensor was implemented in 180nm CMOS process and uses 0.09mm² of area. Measurements from test chips show 65nW power consumption, the lowest reported to date, with an inaccuracy of +1.3°C /-1.4°C across 0°C to 100°C after 2-point calibration.