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 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 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...

Frequency References Based on the Thermal Diffusivity of Silicon and Silicon Dioxide

Conventional methods of generating accurate on-chip frequencies are based on electrical components such as resistors, capacitors, and inductors. Recently, a new type of frequency reference based on the thermal diffusivity (TD) of silicon has been introduced. Such TD frequency references rely on the well defined thermal-domain properties of...

Thermal-Diffusivity-Based Frequency References in Standard CMOS

In recent years, a lot of research has been devoted to the realization of accurate integrated frequency references. A thermal-diffusivity-based (TD) frequency reference provides an alternative method of on-chip frequency generation in standard CMOS technology. A frequency-locked loop locks the output frequency of an oscillator to the accurate...

Design of a fully integrated CMOS highly temperature stable frequency reference

A new fully integrated frequency reference has been designed, fabricated and measured. The goal of the design procedure has been high stability of the frequency over temperature variations. This should be achieved using a CMOS technology without MEMS and crystals, while being restricted by a very low power budget. The frequency is designed based...