Ring Oscillators

In this paper, a simple method allowing optimization of the CMOS ring oscillator frequency dispersion and power consumption is presented. It is shown, that for range of tens of MHz and less, the power consumption and variation of the frequency can be considerably reduced by using 3-stage, resistively coupled ring oscillator, with minimum channel width W and large channel length L MOS transistors. In addition, a simple analysis allowing to estimate the oscillator frequency from the process and transistor parameter values is provided. Keywords Ring oscillator, CMOS inverter delay, CMOS inverter chain, Frequency stability of ring oscillator.

The methodology of hot-carrier reliability assessment has evolved from the traditional DC stressing of devices to circuit-level AC stressing of ring oscillators to hot-carrier reliability simulation. The motivation underlying all these efforts has been the fact that reliability specification at the ...

—A Transient Effect Ring Oscillator (TERO) is a special case of a Ring Oscillator (RO) design that exhibits increased sensitivity to intrinsic noise. It can serve as a basis for implementing a True Random Number Generator (TRNG) or a Physically Uncloneable Function (PUF). Also, as a digital sensor for detecting insertion of malicious hardware logic (Trojans) in digital circuits. In this paper, we explore the application of TERO for detecting hardware Trojans injecting in FPGA implementations of the AES cryptographic algorithm. Experiments and comparisons are reported in terms of the frequency count as a function of the TERO length. Our findings indicate that TERO can be used as a digital sensor for efficiently detecting the presence of a Trojan.

Abstract— In this work we present a prototype circuit to harvest energy from radio waves or through magnetic coupling based on a stack of full-wave rectifiers with transistors working on sub-threshold region. This circuit will use as an input a field-to-voltage converter capable of outputting a ...

Low phase noise monolithic oscillators are in high demand in this age of wireless communications. Although LC oscillators generally have better phase noise performance, there is motivation to design ring oscillators with comparable phase noise compared to LC oscillators. The advantages of ring oscillators include significantly less die area and generally wider tuning range. Ring oscillator phase noise analysis and

In this article, a novel model of phase noise in electrical oscillators is presented. This model is based on Frequency Modulation (FM). The proposed model shows physically and mathematically the effect of oscillator waveform, oscillation frequency and the swing voltage of output waveform on the phase noise. This model also explains why ring oscillators have larger phase noise in compare

The GasP family of asynchronous circuits provides controls for simple pipelines, for branching and joining pipelines, for round-robin scatter and gathel; for datadependent scatter and gathel; and for join on demand through arbitration. The family is designed so that each stage operates at the speed of a three-inverter ring oscillator: Test chips in 0.35 micron technology exhibit throughput in excess of 1.5 giga data items per second

The spurious-free dynamic range (SFDR) of a MOSFET--C filter can be increased greatly by generating its tuning voltage with a charge pump. In this paper, we apply this technique to build a Sallen-and-Key lowpass filter with a pole frequency of 24 MHz and a pole Q of 3. It has an SFDR better than 50 dB and consumes 16 mW from a 3.3 V supply. Implemented with a doublepoly triple-metal 0.6- m CMOS process, it covers an area of only . In addition to a description of the filter and the charge pump, we also discuss linear and non-linear clock feed-through from the charge pump's own ring oscillator, and derive a formula for the optimum voltage swing at the MOSFET--C network nodes. 1.