Starter for Voltage Boost Converter to Harvest Thermoelectric Energy for Body-Worn Sensors

This paper examines the suitability of selected configurations of ultra-low voltage (ULV) oscillators as starters for a voltage boost converter to harvest energy from a thermoelectric generator (TEG). Important properties of particularly promising configurations, suitable for on-chip implementation are compared. On this basis, an improved oscillator with a low startup voltage and a high output voltage swing is proposed. The applicability of n-channel native MOS transistors with negative or near-zero threshold voltage in ULV oscillators is analyzed. The results demonstrate that a near-zero threshold voltage transistor operating in the weak inversion region is most advantageous for the considered application. The obtained results were used as a reference for design of a boost converter starter intended for integration in 180-nm CMOS X-FAB technology. In the selected technology, the most suitable transistor available with a negative threshold voltage was used. Despite using a transistor with a negative threshold voltage, a low startup voltage of 29 mV, a power consumption of 70 µW, and power conversion efficiency of about 1.5% were achieved. A great advantage of the proposed starter is that it eliminates a multistage charge pump necessary to obtain a voltage of sufficient value to supply the boost converter control circuit.

A 916 nW Power LDO Regulator Circuit in 90-nm CMOS Technology for RF SoC Applications

This paper presents a nano-power Low Drop-Out (LDO) voltage regulator circuit for RadioFrequency System-on-Chip (RF SoC) applications, this LDO is designed for a smaller dimension due to CMOS technology and in the weak inversion region, can thus be used to minimize power loss of LDO regulator without transient-response degradation. The proposed structure its low power dissipation make it ideal for RF system-on-chip applications that require low power dissipation under different loading conditions. In order to optimize performance for LDO, the proposed amplifier helps to minimize power of LDO regulators without using any on-chip and off-chip compensation capacitors. The power is 916 nW. The output spot noise at 100Hz and 1 kHz are 200nV/sqrt (Hz) and 6nV/sqrt (Hz), respectively. The active area of the circuit is 850 μm2. The regulator operates with supply voltages from 1.2V to 2V

Nano-Power Low-Dropout Voltage Regulator Circuit in 90-nm CMOS Technology for RF SoC Applications

This paper presents a nano-power Low Drop-Out (LDO) voltage regulator circuit for Radio-Frequency System-on-Chip (RF SoC) applications, this LDO is designed for a smaller dimension due to CMOS technology and in the weak inversion region, can thus be used to minimize power loss of LDO regulator without transientresponse degradation. The proposed structure its low power dissipation make it ideal for RF system-on-chip applications that require low power dissipation under different loading conditions. In order to optimize performance for LDO, the proposed amplifier helps to minimize power of LDO regulators without using any onchip and off-chip compensation capacitors. The output spot noise at 100Hz and 1 kHz are 200nV/sqrt (Hz) and 6nV/sqrt (Hz), respectively. The active area of the circuit is 850 µm2 . The regulator operates with supply voltages from 1.2V to 2V.

A New CMOS OP-AMP Design with an Improved Adaptive Biasing Circuitry

This paper sets out a new technique for designing an operational amplifier (OP-AMP) using tanner EDA 1um FDSOI CMOS Technology. Fully Depleted Silicon on Insulator used for building integrated circuits to support the temperature changes, the proposed OP-AMP operates at 3.75V power supply and 70uA bias current using the proposed Adaptive Biasing Circuitry (ABC), which its devices operate at the weak inversion to allow low power dissipation of 0.62mW. The 0.064us settling time and 37.016V/μs slew rate parameters improved by the ABC technique, reducing the power dissipation by operating the ABC devices in weak inversion. The phase margin is more than 100 degrees for the DC gain of 13.97dB, which is a reasonable margin when temperature range increases.

Implementation of a Fractional-Order Electronically Reconfigurable Lung Impedance Emulator of the Human Respiratory Tree

The fractional-order lung impedance model of the human respiratory tree is implemented in this paper, using Operational Transconductance Amplifiers. The employment of such active element offers electronic adjustment of the impedance characteristics in terms of both elements values and orders. As the MOS transistors in OTAs are biased in the weak inversion region, the power dissipation and the dc bias voltage of operation are also minimized. In addition, the partial fraction expansion tool has been utilized, in order to achieve reduction of the spread of the required time-constants and scaling factors. The performance of the proposed scheme has been evaluated, at post-layout level, using MOS transistors models provided by the 0.35 μ m Austria Mikro Systeme technology CMOS process, and the Cadence IC design suite.

Extended lens reconstructions with grale: exploiting time-domain, substructural, and weak lensing information

ABSTRACT The information about the mass density of galaxy clusters provided by the gravitational lens effect has inspired many inversion techniques. In this article, updates to the previously introduced method in grale are described, and explored in a number of examples. The first looks into a different way of incorporating time delay information, not requiring the unknown source position. It is found that this avoids a possible bias that leads to ‘overfocusing’ the images, i.e. providing source position estimates that lie in a considerably smaller region than the true positions. The second is inspired by previous reconstructions of the cluster of galaxies MACS J1149.6+2223, where a multiply imaged background galaxy contained a supernova, SN Refsdal, of which four additional images were produced by the presence of a smaller cluster galaxy. The inversion for the cluster as a whole was not able to recover sufficient detail interior to this quad. We show how constraints on such different scales, from the entire cluster to a single member galaxy, can now be used, allowing such small-scale substructures to be resolved. Finally, the addition of weak lensing information to this method is investigated. While this clearly helps recover the environment around the strong lensing region, the mass sheet degeneracy may make a full strong and weak inversion difficult, depending on the quality of the ellipticity information at hand. We encounter ring-like structure at the boundary of the two regimes, argued to be the result of combining strong and weak lensing constraints, possibly affected by degeneracies.

High Performance Bulk Driven Operational Trans Conductance Amplifier and Applications

In this paper a bulk driven Fully cascoded operational transconductance amplifier(FCOTA) is designed. OTA applications are designed for voltage controlled current amplifier, filters and analog subtractor. With the current sizing method, all transistors in FCOTA work under weak inversion field. The total current in the proposed amplifier in terms of nano amperes only. As part of low power the circuit operated with the power supply of 0.8V. The main important features of the design are good linearity and accuracy. Full input and output voltage swings. This circuit has been constructed using CMOS technology with UMC90 nm. The circuit’s total power consumption is 620nW