LDMOS versus GaN RF power amplifier comparison based on the computing complexity needed to linearize the output

In order to maximize the efficiency of telecommunications equipment, it is necessary that the radio frequency (RF) power amplifier is situated as closely as possible to its compression ¿point. This makes its response nonlinear, and therefore it is necessary to linearize it, in order to minimize the interference that nonlinearities cause outside the useful band (adjacent channel). The system used for this linearization occupies a high percentage of the hardware and software resources of the telecommunication equipment, so it is interesting to minimize its complexity in order to make it as simple as possible. This paper analyzes the differences between the laterally diffused MOSFET (LDMOS) and gallium nitride (GaN) power amplifiers, in terms of their nonlinearity graphs, and in terms of the greater or lesser difficulty of linearization. A correct choice of power amplifier will allow for minimization of the linearization system, greatly simplifying the complexity of the final design

A Low-quiescent Current Full on-chip 1.2 V CMOS Low Drop-Out Regulator

This paper presents a fully-integrated low-power 0.18 µm CMOS Low-Dropout (LDO) regulator for battery operated portable devices. It provides an accurate 1.2 V output voltage from 3.3 V to 1.3 V input voltages up with only 5.9 µA quiescent current, including an all-MOS 0.4 V reference voltage

A CMOS low pass filter for soc lock-in-based measurement devices

This paper presents a fully integrated Gm–C low pass ¿lter (LPF) based on a current ¿steering Gm reduction-tuning technique, specifically designed to operate as the output stage of a SoC lock-in amplifier. To validate this proposal, a first-order and a second-order single-ended topology were integrated into a 1.8 V to 0.18 µm CMOS (Complementary Metal-Oxide-Semiconductor) process, showing experimentally a tuneable cutoff frequency that spanned five orders of magnitude, from tens of mHz to kHz, with a constant current consumption (below 3 µA/pole), compact size (<0.0140 mm2 /pole), and a dynamic range better than 70 dB. Compared to state-of-the-art solutions, the proposed approach exhibited very competitive performances while simultaneously fully satisfying the demanding requirements of on-chip portable measurement systems in terms of highly efficient area and power. This is of special relevance, taking into account the current trend towards multichannel instruments to process sensor arrays, as the total area and power consumption will be proportional to the number of channels

1.0 v-0.18 µm CMOS tunable low pass filters with 73 db dr for on-chip sensing acquisition systems

This paper presents a new approach based on the use of a Current Steering (CS) technique for the design of fully integrated Gm–C Low Pass Filters (LPF) with sub-Hz to kHz tunable cut-off frequencies and an enhanced power-area-dynamic range trade-off. The proposed approach has been experimentally validated by two different first-order single-ended LPFs designed in a 0.18 µm CMOS technology powered by a 1.0 V single supply: a folded-OTA based LPF and a mirrored-OTA based LPF. The first one exhibits a constant power consumption of 180 nW at 100 nA bias current with an active area of 0.00135 mm2 and a tunable cutoff frequency that spans over 4 orders of magnitude (~100 mHz–152 Hz @ CL = 50 pF) preserving dynamic figures greater than 78 dB. The second one exhibits a power consumption of 1.75 µW at 500 nA with an active area of 0.0137 mm2 and a tunable cutoff frequency that spans over 5 orders of magnitude (~80 mHz–~1.2 kHz @ CL = 50 pF) preserving a dynamic range greater than 73 dB. Compared with previously reported filters, this proposal is a competitive solution while satisfying the low-voltage low-power on-chip constraints, becoming a preferable choice for general-purpose reconfigurable front-end sensor interfaces

A Low Pass Filter With sub-Hz Cutoff Frequencies for a Portable On-Chip Lock-in Microinstrument

This paper presents a first-order single-ended fully-integrated Low Pass Filter (LPF) tunable from 114 mHz to 2.5 kHz, designed to conform the output stage of a portable lock-in amplifier requiring fc = 0.5 Hz, 5 Hz cutoff frequencies. It achieves the two target fc over a -40 to 120 °C range with a power consumption of 2.7 μW at 1.8 V supply, compact size and dynamic range above 80 dB.Este artículo presenta un filtro pasa baja (LPF) completamente integrado de primer orden programable de 114 mHz a 2.5 kHz, diseñado para formar parte de la etapa de salida de un Amplificador Lock-In portátil que requiere frecuencias de corte fc = 0.5, 5 Hz . Alcanza las dos frecuencias de corte objetivo en un rango de -40 a 120 °C con un consumo de energía de 2.7 μW, una tensión de alimentación de 1.8 V, un tamaño compacto y un rango dinámico por encima de los 80 dB

A Digitally Programmable Analog Quadrature Sine Oscillator for on-chip Lock-In Measurement Systems

This paper presents a CMOS 1.8V-180nm analog quadrature sine oscillator. Thanks to a custom 12-bit bidirectional DAC-based architecture, the frequency can be digitally programmed over two decades with high accuracy, making it suitable as the actuation system in low-cost high-performance embedded lock-in measurement systems

A compact energy harvesting system for outdoor wireless sensor nodes based on a low-cost in situ photovoltaic panel characterization-modelling unit

This paper presents a low-cost high-efficiency solar energy harvesting system to power outdoor wireless sensor nodes. It is based on a Voltage Open Circuit (VOC) algorithm that estimates the open-circuit voltage by means of a multilayer perceptron neural network model trained using local experimental characterization data, which are acquired through a novel low cost characterization system incorporated into the deployed node. Both units—characterization and modelling—are controlled by the same low-cost microcontroller, providing a complete solution which can be understood as a virtual pilot cell, with identical characteristics to those of the specific small solar cell installed on the sensor node, that besides allows an easy adaptation to changes in the actual environmental conditions, panel aging, etc. Experimental comparison to a classical pilot panel based VOC algorithm show better efficiency under the same tested conditions

Hertz-Resolution Analog Quadrature Sine Oscillator. Application to Portable Lock-In Amplifiers

This paper presents the implementation of an analog quadrature sine oscillator capable of generating variable frequency quadrature signals, ranging from 1-100 kHz with less than 2 Hz resolution and a peak-to-peak voltage of 3 V operating at a 3.3 V single supply, to be utilized in high performance portable instrumentation

A Digitally Programmable Active-RC Filter for On-Chip Portable Sensor Applications

An enhanced digital tuning approach for RC-active circuits is presented. Simulations of a 12-bit CMOS second-order filter provide a 11.46-bit effective resolution to linearly control the frequency over three decades with THD<-70 dB. Its low power, 0.5 mW, and low active area, 0.087 mm2, prove its suitability for on-chip sensing systems

A 180nm CMOS Capacitorless Low Drop-Out Regulator for Battery-operated System

This paper presents a fully-integrated 180nm CMOS low drop-out regulator based on a simple telescopic cascode-compensated amplifier driving a PMOS pass-device. It provides a high precision 1.8V output voltage for battery voltages from 3.6V to 1.93V up to a 50mA load current with only 22μA quiescent current