Near-Zero-Power Temperature Sensing via Tunneling Currents Through Complementary Metal-Oxide-Semiconductor...

Area of Science:

• Semiconductor device physics
• Integrated circuit design
• Low-power electronics

Background:

• Temperature sensors are crucial for various monitoring applications.
• Limited power availability in devices necessitates low-power sensing solutions.
• Existing sensors often have high power consumption, limiting operational lifetime.

Purpose of the Study:

• To develop a new method for transducing and digitizing temperature at extremely low power levels.
• To minimize power consumption in temperature sensors for extended operational lifetime.
• To present a novel silicon microchip-based temperature sensor.

Main Methods:

• Utilizing two pA current references generated by tunneling-current metal-oxide-semiconductor field-effect transistors (MOSFETs).
• Employing digitally-controllable metal-insulator-metal (MIM) capacitors charged by these current references.
• Implementing a discrete-time feedback loop to equalize charging time for direct temperature digitization.

Main Results:

• The developed temperature sensor integrates into a 0.15 mm² silicon microchip.
• Measured power consumption is as low as 113 pW.
• Achieved a resolution of 0.21 °C and an inaccuracy of ±1.65 °C.
• Demonstrated a 628× reduction in power compared to prior art.

Conclusions:

• The proposed method effectively digitizes temperature at ultra-low power levels.
• This technology significantly enhances the operational lifetime of battery-powered or energy-harvesting devices.
• Represents a substantial advancement in low-power temperature sensing for diverse applications.