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This paper investigates a high power factor switch-based wireless power transfer front-end circuit for heterogeneous systems. This circuit uses an integrated switching rectifier, implemented in 0.18um 1.8V/5V CMOS process. An integrated pair of phase synchronizers is used to align the waveshape of a wirelessly-coupled sinusoidal voltage source in the receiving coil to the corresponding conducting...
A 7GS/s 6b sub-ranging ADC is implemented in 32nm CMOS SOI with reconfigurable comparators, and adjustable input differential pairs are exploited to change converter characteristics for hardware-based cybersecurity. To achieve low-power consumption at high-speed operation with small-size transistors, an on-chip calibration to reduce process mismatches is utilized in the design. The presented ADC achieves...
In this paper, effects of amplifier distortion in DT sigma-delta modulator are discussed. A second order modulator with single-bit quantizer is modeled and dead-zone effect of ring amplifiers in integrators is simulated by using MATLAB. For the evaluation of dead-zone effect on modulator distortion, test chip was fabricated in 65nm CMOS. SNDR of 62dB and 1MHz signal bandwidth was experimentally demonstrated...
This paper presents the design of a zero-voltage-ripple (ZVR) buck dc-dc converter. The circuit uses an autotransformer for ripple cancellation in the output voltage. The principle of operation is discussed in brief. The relationship between the currents through the magnetizing inductance and the auto-transformer windings is developed. The auxiliary inductance for ripple cancellation in series with...
The audio-susceptibility of the average current-mode controlled buck dc-dc converter in continuous-conduction mode is presented in this paper. The average current-mode control scheme used in this paper regulates the true average component of the sensed inductor current and is not affected by a high inductor current ripple at low duty ratios. The principle of negative feedback for converters with the...
In this paper, we illustrate, through examples, a novel graph-based modeling technique of two-state (on-off) PWM power converters. Differential equations of power converters are derived by inspection, based on two incident matrices, β(u) and J(u). We associate to each circuit (on, u = 1, or off, u = 0, circuits) a digraph and identify current loops (inductor-capacitor, voltage source-inductor, current...
A Li-ion battery charger with dual input source capability and high efficiency is proposed in this work. An internal source determination circuit could choose the sufficient energy source for charging system. Also, a new approach of smooth transition to avoid oscillation between charging mode switching is used through current-mode-like smooth transition circuit. Pulse frequency modulation with adaptive...
The future naval surface combatant will be an all-electric medium-voltage dc integrated power and energy system; capable of supporting future dynamic loads, such as electric weapons and sensors. This system will be different from typical terrestrial distribution systems in that current carrying conductors are in close proximity to the conductive ship hull structure, and there is no well-defined ‘earth’...
In this paper, an analytical approach is proposed for solving a special set of transcendental equations, which are often encountered for eliminating harmonics in converters. Typically, numerical solutions are used for solving the transcendental equations. The disadvantage of numerical approach is overhead in computational effort as it requires a PC with expensive software and solution time can also...
Recently a discrete Hankel transform (DHT) has been introduced using a symmetric involutory kernel matrix T. Although Namias contributed the fractional Hankel transform (FRHT) in 1980, no discrete counterpart has appeared till now. Here a definition is proposed for a discrete fractional Hankel transform (DFRHT) based on the eigen decomposition of the diagonalizable matrix T. Being a real symmetric...
This paper presents an original and unique embedded FFT hardware algorithm development process based on a systematic and scalable procedure for generating permutation-based address patterns for any power-of-2 transform size algorithm and any folding factor in a Kronecker Pease FFT hardware implementation. This is coupled by a procedure to perform automatic code generation of Kronecker FFT cores. The...
The Sun has the potential to provide 89,300 tera Watts of power to our planet. Our ability to convert even a fraction of this energy for human use makes a significant impact on current energy generation and consumption trends. World-wide we now add more renewable energy capacity every year than (combined) fossil fuel energy capacity. Solar panels provide a reliable, renewable, non-polluting energy...
This paper presents the steps we have taken towards implementing a reliable and robust data link that is necessary for an intraoral Tongue Drive System (iTDS), which is a wireless and wearable assistive technology (AT). The iTDS detects the user's intention from a set of user-defined commands that are defined based on tongue gestures to control wheelchair, phone, PC, etc. To deal with potential sources...
We review two generations of smart bandages and sensors developed in our group. These devices are capable of monitoring and treating chronic wounds through O2, pH and strain measurement and on-demand drug delivery. First we seek to close the gap between patient and caregivers through continuous monitoring of wound healing status with oxygenation measurements coupled with wireless data acquisition...
A CMOS integrated frequency domain near infrared spectroscopy (fdNIRS) and transcranial direct current stimulation (tDCS) is designed for simultaneous brain stimulation and monitoring. The combination of optical sensing and electrical stimulation solves the incompatibility between EEG and tDCS in both time and spatial domains. A real-time closed-loop brain stimulation can be realized for neurological...
We present the design and implementation of a monolithic microwatt analog front end and asynchronous level-crossing ADC for efficient capture of sparse biopotentials. The low-noise differential AC-coupled front-end provides +40 dB gain, and the signal is digitized by an asynchronous level-crossing ADC which encodes the signal slope into a stream of pulses. For temporally-sparse signals such as single-unit...
This work is aimed toward the goal of investigating the influence of different materials on the signal-to-noise ratio (SNR) of passive neural microelectrode arrays (MEAs). Noise reduction is one factor that can substantially improve neural interface performance. The MEAs are fabricated using gold, indium tin oxide (ITO), and chemical vapor deposited (CVD) graphene. 3D-printed Nylon reservoirs are...
Simulation of complex hardware circuits is the basis for many EDA tasks and is commonly used at various phases of the design flow. State-of-the-art simulation tools are based upon discrete event simulation algorithms and are highly optimized and mature. Symbolic simulation may also be implemented using a discrete event approach, or other approaches based on extracted functional models. The common...
High performance chip design is always a hot topic in integrated circuit (IC) field. Clock design plays a critical role in improving chip performance and affecting power consumption. The regular clock layout has always been the ideal way to improve the timing of results. In this paper, we propose a symmetrical clock tree synthesis algorithm for top-level design, including tree architecture planning,...
A formal modeling and verification methodology for Pre-Charge Half Buffer (PCHB) gates and circuits is presented. PCHB gates have hysteresis and incorporate a handshaking protocol. Thus, we model gates as transition systems and provide correctness property templates that capture safety and liveness. The methodology is demonstrated using several circuits.
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