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 16 MHz CMOS RC Frequency Reference With ±90 ppm Inaccuracy From -45 °C to 85 °C

This article presents a 16-MHz RC frequency reference implemented in a standard 180-nm CMOS process. It consists of a frequency-locked loop (FLL) in which the output frequency of a digitally controlled oscillator (DCO) is locked to the frequency-phase characteristic of a Wien bridge RC filter. Since it is made from on-chip resistors and...

A Compact Resistor-Based Temperature Sensor

Smart temperature sensors can be used for the temperature compensation of micro-electromechanical (MEMS) frequency references. From the different types of CMOS temperature sensors, resistor-based sensors are currently the most energy-efficient. However, compared with bipolar transistor (BJT)-based temperature sensors, resistors suffer from...

A 5800-μm² Resistor-Based Temperature Sensor with a One-Point Trimmed Inaccuracy of ±1.2 °c (3σ) from -50 °c to 105 °c in 65-nm CMOS

This letter describes a compact resistor-based temperature sensor intended for the thermal monitoring of microprocessors and DRAMs. It consists of an RC poly phase filter (PPF) that is read out by a frequency-locked loop (FLL) based on a dual zero-crossing (ZC) detection scheme. The sensor,fabricated in 65-nm CMOS,occupies 5800 μm²...

A 5800-μ m ₂Resistor-Based Temperature Sensor with a One-Point Trimmed Inaccuracy of ±1.2 °c (3σ) From-50 °c to 105 °c in 65-nm CMOS

This letter describes a compact resistor-based temperature sensor intended for the thermal monitoring of microprocessors and DRAMs. It consists of an RC poly phase filter (PPF) that is read out by a frequency-locked loop (FLL) based on a dual zero-crossing (ZC) detection scheme. The sensor, fabricated in 65-nm CMOS, occupies 5800 μ m2 and...

A CMOS Dual- RC Frequency Reference With ±200-ppm Inaccuracy From -45 °C to 85 °C

This paper presents a 7-MHz CMOS RC frequency reference. It consists of a frequency-locked loop in which the output frequency of a digitally controlled oscillator (DCO) is locked to the combined phase shifts of two independent RC (Wien bridge) filters, each employing resistors with complementary temperature coefficients. The filters are driven...

A Compact Resistor-Based CMOS Temperature Sensor With an Inaccuracy of 0.12 °C (3σ) and a Resolution FoM of 0.43 pJ·K² in 65-nm CMOS

This paper presents a compact resistor-based CMOS temperature sensor intended for dense thermal monitoring. It is based on an RC poly-phase filter (PPF), whose temperature-dependent phase shift is read out by a frequency-locked loop (FLL). The PPF's phase shift is determined by a zero-crossing (ZC) detector, allowing the rest of the FLL to be...

A Digital-Intensive Wakeup Timer based on an RC Frequency-Locked Loop for Internet-of-Things Applications

This thesis presents an ultra-low power wakeup timer locked to an RC time constant that can meet the stringent power requirements of the nodes for Internet-of-Things (IoT) applications. The wakeup timer, fabricated in a 40-nm CMOS process, employs a bang-bang digital-intensive frequency-locked loop (DFLL). A self-biased ΣΔ digitally controlled...

A Precision RC-locked Oscillator

In this thesis, the development and implementation of a new precision RC-locked oscillator topology suitable for wireless sensor networks (WSNs) is described. The objective of this thesis was to investigate the performance of the proposed topology and to compare this with the state-of-the-art in terms of accuracy and power consumption. The new...