Compact Resistor-Based Temperature Sensors for On-Chip Thermal Monitoring

Advanced Systems-on-Chip (SoCs) exhibit significant self-heating and require thermal management to prevent overheating. Sensors for this application should be not only small so that they can be placed ubiquitously, but they should also achieve moderate accuracy and resolution within 1 ms so that the die temperature can be monitored with...

A 210 nW NPN-Based Temperature Sensor With an Inaccuracy of ±0.15 °C (3σ) From −15 °C to 85 °C Utilizing Dual-Mode Frontend

This letter describes an NPN-based temperature sensor that achieves a 1-point trimmed inaccuracy of ±0.15 °C (3σ) from -15 to 85 °C while dissipating only 210 nW. It uses a dual-mode frontend to roughly halve the power consumption of conventional frontends. First, two NPNs are used to generate a well-defined PTAT bias current, then this...

A 0.9-V 28-MHz Highly Digital CMOS Dual-RC Frequency Reference With ±200 ppm Inaccuracy From -40 °C to 85 °C

This article presents an energy-efficient dual- RC frequency reference intended for wireless sensor nodes. It consists of a digital frequency-locked loop (FLL) in which the frequency of a digitally controlled oscillator (DCO) is locked to a temperature-independent phase shift derived from two different RC poly-phase filters (PPFs). Phase...

A 210nW BJT-based Temperature Sensor with an Inaccuracy of ±0.15°C (3s) from -15°C to 85°C

This paper presents a 210nW BJT-based temperature sensor that achieves an inaccuracy of ±0.15°C (3s) from -15°C to 85°C. A dual-mode front-end (FE), which combines a bias circuit and a BJT core, halves the power needed to generate well-defined CTAT (VBE) and PTAT (?VBE) voltages. The use of a tracking ?S ADC reduces FE signal swing and...

5.4 A Hybrid Thermal-Diffusivity/Resistor-Based Temperature Sensor with a Self-Calibrated Inaccuracy of ±0.25° C(3 Σ) from -55°C to 125°C

Resistor-based temperature sensors can achieve higher resolution and energy-efficiency than traditional BJT-based sensors. To reach similar accuracy, however, they typically require 2-point (2-pt) calibration, compared to the low-cost 1-pt calibration required by BJT-based sensors. This paper presents a hybrid temperature sensor that uses an...

A Highly Digital 2210μm²Resistor-Based Temperature Sensor with a 1-Point Trimmed Inaccuracy of ± 1.3 ° C (3 σ) from -55 ° C to 125 ° C in 65nm CMOS

Microprocessors and SoCs employ multiple temperature sensors to prevent overheating and ensure reliable operation. Such sensors should be small (<10,000μm2) to monitor local hot-spots in dense layouts. They should also be moderately accurate (1°C) up to high temperatures (≥125°C), so that the system throttling temperature can be set as...

31.2 A 0.9V 28MHz Dual-RC Frequency Reference with 5pJ/Cycle and ±200 ppm Inaccuracy from -40°C to 85°C

Wireless sensor nodes in battery-powered internet-of-things (loT) applications require a stable on-chip frequency reference with low energy (<10 pJ / cycle) and high frequency stability (below ±300ppm). CMOS RC frequency references are promising due to their low-cost integration and high energy efficiency [1] –[5]. Conventional RC references,...

A Self-Calibrated Hybrid Thermal-Diffusivity/Resistor-Based Temperature Sensor

This article describes a hybrid temperature sensor in which an accurate, but energy-inefficient, thermal diffusivity (TD) sensor is used to calibrate an inaccurate, but efficient, resistor-based sensor. The latter is based on silicided polysilicon resistors embedded in a Wien-bridge (WB) filter, while the former is based on an electrothermal...

A 6800-μ m² Resistor-Based Temperature Sensor with ±0.35 °c (3σ) Inaccuracy in 180-nm CMOS

This paper describes a compact resistor-based temperature sensor that has been realized in a 180-nm CMOS process. It occupies only 6800 μ m², thanks to the use of a highly digital voltage-controlled oscillator (VCO)-based phase-domain sigma-delta modulator, whose loop filter consists of a compact digital counter. Despite its small...

A 6800-μm² Resistor-Based Temperature Sensor in 180-nm CMOS

A resistor-based temperature sensor has been realized in 180 nm CMOS for SoC thermal management applications. Occupying only 6800 μm², it is the smallest resistor-based temperature sensor ever reported. This is achieved by employing a compact highly-digital VCO-based ADC. After a 2-point trim, the sensor achieves an inaccuracy of ...