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 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 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...