A Wheatstone Bridge Temperature Sensor with a Resolution FoM of 20fJ.K ²

Temperature sensors intended for embedded applications should be both energy-and area-efficient. The combination of Wheatstone-bridge (WhB) sensors and continuous-time ADCs has proven to be highly energy efficient [1], [2]. However, their area (> 0.25 mm{2}) is still larger than that of comparable BJT-based sensors [3], [4]. This paper...

A 0.12mm² Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C

Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm ² ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm ² resistor-based sensor that uses a...

A 0.53pJK27000μm2resistor-based temperature sensor with an inaccuracy of ±0.35°C (3σ) in 65nm CMOS

In microprocessors and DRAMs, on-chip temperature sensors are essential components, ensuring reliability by monitoring thermal gradients and hot spots. Such sensors must be as small as possible, since multiple sensors are required for dense thermal monitoring. However, conventional BJT-based temperature sensors are not compatible with the sub...

A ±4A high-side current sensor with 25V input CM range and 0.9% gain error from -40°C to 85°C using an analog temperature compensation technique

This paper presents a fully integrated ±4A current sensor that supports a 25V input common-mode voltage range (CMVR) while operating from a single 1.5V supply. It consists of an on-chip metal shunt, a beyond-the-rails ADC [1] and a temperature-dependent voltage reference. The beyond-the-rails ADC facilitates high-side current sensing without...

A CMOS Dual-RC frequency reference with ±250ppm inaccuracy from -45°C to 85°C

To comply with wired communication standards such as USB, SATA and PCI/PCI-E, systems-on-chip require frequency references with better than 300ppm accuracy. LC-based references achieve 100ppm accuracy [1], but suffer from high power consumption (∼20mW). Thermal diffusivity (TD) references require less power (∼2mW), at the expense of less...

A phase-domain readout circuit for a CMOS-compatible thermal-conductivity-based carbon dioxide sensor

The measurement of carbon-dioxide (CO2) concentration is very important in home and building automation, e.g. to control ventilation in energy-efficient buildings. This application requires compact, low-cost sensors that can measure CO₂ concentration with a resolution of <200 ppm over a 2500ppm range. Conventional optical (NDIR...

A CMOS Temperature Sensor with a 49fJ·K2 Resolution FoM

This paper presents the most energy-efficient CMOS temperature sensor ever reported, with a resolution FoM of 49fJ·K2, 2.7× better than the state-of-the-art. It consists of a Wheatstone bridge made from poly-silicon resistors, which is readout by a 2nd-order Continuous-Time Delta-Sigma modulator (CTDSM). This approach leads to a high resolution ...

A CMOS temperature sensor with a voltage-calibrated inaccuracy of ±0.15°C (3σ) from -55 to 125°C

This paper describes an energy-efficient CMOS temperature sensor intended for use in RFID tags. The sensor achieves an inaccuracy of ±0.15°C (3σ) over the military temperature range (-55 to 125°C) and dissipates only 27nJ/conversion: over 20× less than a previous sensor with comparable accuracy and resolution [2]. This energy efficiency is...