CMOS-Based Temperature Sensing Systems

Complementary metal–oxide–semiconductor (CMOS) temperature sensors have become integral to modern electronics, enabling precise on-chip thermal monitoring, environmental sensing and wearable applications. By leveraging standard CMOS fabrication, these sensors can be co-integrated with digital and analogue circuitry, minimising cost and footprint while maximising scalability. Various architectures exist, including diode-connected MOSFET elements, bipolar junction transistor (BJT) front-ends, ring-oscillator delay lines and time-domain converters. Key performance metrics—accuracy, resolution, power consumption and area—are carefully balanced through techniques such as proportional-to-absolute-temperature (PTAT) current generation, subthreshold operation and curvature compensation. Recent advances target ultra-low-power regimes suitable for energy-harvesting devices and dense thermal mapping in hot-spot-critical processors. The global impact spans from consumer electronics thermal management and grid monitoring to medical wearables and environmental networks, underscoring the pervasive role of CMOS-based temperature sensing systems.

Research from Nature Portfolio

A seminal study introduced an ultra-low-power temperature sensor that exploits tunnelling currents in MOSFET devices to generate two temperature-dependent current references. These currents charge discrete metal–insulator–metal capacitor banks within a closed-loop architecture, directly digitising temperature with minimal analogue overhead. The fully integrated silicon microchip occupies 0.15 mm2 and achieves a resolution of 0.21 °C with an inaccuracy of ±1.65 °C, all while consuming only 113 pW. This breakthrough demonstrates the feasibility of pW-level operation in CMOS, paving the way for long-lifetime wireless sensors and energy-harvesting systems in distributed monitoring applications.

Research from all publishers

Building on diode-connected NMOS devices, a compact 32 µm2 temperature sensor fabricated in a 180 nm process achieves three-sigma errors within ±0.1 °C from 75 °C to 95 °C and ±1.29/−1.08 °C outside this range. A novel on-chip voltage calibration method enhances extraction accuracy, enabling dense deployment around thermal hotspots in high-performance integrated circuits. Another notable advance is a subranging BJT-based CMOS sensor spanning −50 °C to 180 °C. It introduces a nonlinear readout scheme with dynamic reconfiguration and double sampling to relax resolution requirements and reduce conversion time. Implemented in 0.18 µm CMOS, it achieves a resolution figure-of-merit of 7.2 pJ·K2 at 150 °C and an inaccuracy of ±0.45 °C under 1.5 V supply, highlighting significant gains in energy efficiency and wide-range performance.

CMOS-Based Temperature Sensing Systems publication trend

The graph below shows the total number of articles in cmos-based temperature sensing systems across all publications each year (not limited to Nature Index journals).

Technical terms

CMOS: A silicon technology in which complementary pairs of MOSFETs are used to implement logic and analogue functions with low static power consumption.

MOSFET: A field-effect transistor in which current through a semiconductor channel is modulated by an electric field across an oxide layer.

PTAT (Proportional To Absolute Temperature): A current or voltage signal that varies linearly with absolute temperature, commonly generated using paired device characteristics.

BJT (Bipolar Junction Transistor): A three-terminal semiconductor device that utilises electron and hole injection to produce currents with strong temperature dependence.

Tunnelling Current: A temperature-sensitive quantum-mechanical current flowing through a thin insulator between semiconductor regions, used for ultra-low-power sensing.

References

1. Near-Zero-Power Temperature Sensing via Tunneling Currents Through Complementary Metal-Oxide-Semiconductor Transistors. Scientific Reports (2017).
2. A 32 μm2 MOS-Based Remote Sensing Temperature Sensor with 1.29 °C Inaccuracy for Thermal Management. Computers (2025).
3. Subranging BJT-Based CMOS Temperature Sensor With a ±0.45 °C Inaccuracy (3σ) From −50 °C to 180 °C and a Resolution-FoM of 7.2 pJ·K² at 150 °C. IEEE Journal of Solid-State Circuits (2022).