IEEE Transactions on Circuits and Systems I: Regular Papers

Analysis simplified with circuit insights reveals the major sources of distortion in a passive FET-switch-based sampling circuit: 1) $R_{mathrm{scriptscriptstyle ON}}$ -modulation; 2) turn-OFF-time instant; and 3) signal-dependent charge-injection. Explicit expressions for second- and third-order distortions advance intuitive understanding of the processes of distortion. Circuit simulations and me... View full abstract»

As the integrated circuit (IC) technology advances into smaller nanometre feature sizes, a fixed-error noise known as device mismatch is introduced owing to the dissimilarity between transistors, and this degrades the accuracy of analog circuits. In this paper, we present an analog co-processor that uses this fixed-pattern noise to its advantage to perform complex computation. This circuit is an e... View full abstract»

A low-power low-noise chopper amplifier for biosensor applications is proposed. To tackle the inherent ripple artifacts, it employs a simple ripple reduction method using a bandpass amplifier. The chopper amplifier is a linear periodic time-varying system. The method of harmonic transfer matrix is used to derive the signal and the noise harmonic transfer functions, and the theoretical results are ... View full abstract»

Traditionally, a transconductor-C (Gm-C)-based delta sigma modulator (DSM) has its performance limited by the nonlinearity of its Gm circuits. To achieve sufficient linearity, source degeneration is typically applied to a Gm circuit, which inevitably reduces the Gm circuit's transconductance and thermal noise efficiencies. This paper presents new ways to change this paradigm. First, a DSM topology... View full abstract»

We present a novel BiCMOS-based temperature compensation technique aiming at complete correction of the curvature in the temperature response of bandgap references. The source of the appearance of this curvature is because the well-known nonlinear term T ln(T) in the base-emitter voltage (VBE) is not completely canceled across all temperature points. Here, we show that the gate-source v... View full abstract»

A unique readout circuit topology aimed at integration with a novel type of magnetic random access memory (MRAM) is presented. The properties of the new MRAM bitcell are introduced, and the specifics of the circuit used to interface with the CMOS circuitry are described. The noise transfer function and effectiveness of the proposed topology with its practical limitations are discussed. Post-silico... View full abstract»

A novel modeling methodology of Schottky diode for microwave rectifier design is proposed in this paper. The challenge was to consider the effective capacitance of the diode under different status being usually ignored in previous works. In addition, the charging and discharging behaviors causing extra power consumption had been considered for a higher modeling accuracy. To improve the diode model... View full abstract»

Gain-cell embedded DRAM (GC-eDRAM) is a possible alternative to traditional static random access memories (SRAM). While GC-eDRAM provides high-density, low-leakage, low-voltage, and inherent2-ported operation, its limited retention time requires periodic, power-hungry refresh cycles. This drawback is further aggravated at scaled technologies, where increased subthreshold leakage currents and decre... View full abstract»

A 128-kb ultra-low voltage SRAM, based on a leakage optimized single-WELL 7T bitcell in 28-nm FD-SOI technology is presented. An ideal power management scenario in a single supply system is achieved by permanently keeping the storage elements in the vicinity of the retention voltage. Performance and reliability is regained by boosting the voltage on critical nodes. The cost of voltage boost genera... View full abstract»

This paper proposes a novel approach to enhance the STT-MRAMs read margin based on the concept of dynamic reference (DR). Our dynamic reference scheme dynamically adjusts the sense amplifier reference voltage according to the bitline voltage, aiming to widen the difference between the bitline and the reference voltage (i.e., the read margin). As a result, larger variations can be accommodated, thu... View full abstract»

This paper introduces a new concept of a true random number generator (TRNG) based on two stages of randomness. The first stage is based on a novel chaotic circuit, which utilizes time as a continuous random variable in a feedback loop. The second stage is based on metastability; however, in contrast to known digital solutions, a flip-flop is stimulated by chaotic initial conditions. The advantage... View full abstract»

Soft errors produced by radiation events can cause malfunctions in modern day electronics. To preserve the system functionality, its elements must be protected against the effects of these events. Two of the possible techniques usually employed to implement fault tolerant registers are triple modular redundancy (TMR) and single error correcting (SEC) codes. However, the use of these techniques inc... View full abstract»

Filter design with short transient state is a problem encountered in many fields of circuits, systems, and signal processing. In this paper, a novel low-pass filter design technique with time-varying parameters is introduced in order to minimize the rise-time parameter. Through the use of calculus of variations a method is developed to obtain the optimal closed-form expression for adjusting the pa... View full abstract»

Edge analytics support industrial Internet of Things by pushing some data processing capacity to the edge of the network instead of sending the streaming data captured by the sensor nodes directly to the cloud. It is advantageous to endow machine learners for data reduction with suitable security primitives for privacy protection in edge computing devices to conserve area and power consumption. In... View full abstract»

This paper considers a large class of memristor circuits of arbitrary order, and containing an arbitrary number of flux- or charge-controlled memristors, for which a state equation (SE) description can be obtained. By means of the SEs, it is shown that the state space of each circuit can be decomposed in infinitely many manifolds, and that in the autonomous case, each manifold is positively invari... View full abstract»

With advantages of small size, light weight, and fast tuning capability, electronic impedance synthesizer (EIS) presents game-changing opportunities for industry. However, their widely acceptance is still restrained by the understanding of power-handling capacity and linearity issues. This work addresses both issues through the development of a voltage distribution theory which enables simulating ... View full abstract»

In the past few years, the demand for real-time hardware implementations of deep neural networks (DNNs), especially convolutional neural networks (CNNs), has dramatically increased, thanks to their excellent performance on a wide range of recognition and classification tasks. When considering real-time action recognition and video/image classification systems, latency is of paramount importance. T... View full abstract»

In this paper, a novel analysis method based on wave digital (WD) principles is presented. The method is employed for modeling and efficiently simulating large photovoltaic (PV) arrays under partial shading conditions. The WD method allows rapid exploration of the current-voltage curve at the load of the PV array, given: the irradiation pattern, the nonlinear PV unit model (e.g., exponential junct... View full abstract»

The cooperative output regulation problem for singular multi-agent systems subject to static networks was studied recently under the assumption that each follower system satisfies the standard assumption. In this paper, we further study the same problem for singular multi-agent systems subject to jointly connected switching networks. First, by introducing a static output feedback control, we remov... View full abstract»

This paper investigates the event-based control for network systems. Edge-based approach is utilized to predict the value of edge state between two event instants. Different from the node-based approach, it can significantly reduce the communication burden at event instants. Based on the small gain theorem, the closed-loop system is expressed as the feedback interconnection of a linear time-invari... View full abstract»

In this paper, we design a no-overloading error feedback quantizer based on a AΣ modulator, composed of an error feedback filter and a static quantizer. To guarantee no-overloading in the quantizer, we impose an l∞ norm constraint on the feedback signal in the quantizer. Then, for a prescribed l∞ norm constraint on the error at the system output induced b... View full abstract»

This paper presents a millimeter-wave fully differential transformer-based passive reflection-type phase shifter (RTPS) capable of performing full span 360° continuous phase shift from 58 to 64 GHz. It consists of two transformerbased 90° couplers and two transformer-based multi-resonance reflective loads to provide 360° phase shift with low loss and ultra-compact chip size. O... View full abstract»

Powerful forward error correction (FEC) schemes are used in optical communications to achieve bit-error rates (BERs) below 10-15. These FECs follow one of two approaches: the concatenation of simpler hard-decision codes or the usage of inherently powerful soft-decision codes. The first approach yields lower net coding gains (NCGs), but can usually work at higher code rates and have lowe... View full abstract»