No abstract

Under IEEE-754 standard, for the current situation of excessive time and power consumption of multiplication operations in single-precision floating-point operations, the expanded boothwallace algorithm is used, and the partial product caused by booth coding is rounded and predicted with the symbolic expansion idea, and the partial product caused by single-precision floating-point multiplication and the accumulation of partial products are optimized, and the flowing water is used to improve the throughput. Based on this, a series of verification and synthesis simulations are performed using the SMIC-7 nm standard cell process. It is verified that the new single-precision floating-point multiplier can achieve a smaller power share compared to the conventional single-precision floating-point multiplier.

This paper presents a new signal demodulator for ultra-high frequency (UHF) radio frequency identification (RFID) tag chips. The demodulator is used to demodulate amplitude shift keying (ASK) modulated signals with the advantages of high noise immunity, large input range and low power consumption. The demodulator consists of a charge pump, an envelope detector, and a comparator. In particular, the demodulator provides a hysteresis input signal to the comparator through two envelope detectors, resulting in better noise immunity. The demodulator is based on a standard 0.13 µm CMOS process. The demodulator is suitable for demodulating high frequency signals at 900 MHz with a data rate of 128 Kbps and can operate up to 78 °C. The input signal has a peak of 1.2 V and consumes as little as 113.6 nW. The demodulator also has a noise immunity threshold of approximately 3.729 V.

A new type of energy-saving magnetic amplifier controlling current and voltage of inductive load has been designed. The energy-saving magnetic amplifier with two windings wrapped across one iron core column can change impedance of the main winding by means of PWM controlling AC excitation current. The energy-saving magnetic amplifier has not used a special adjustable DC voltage circuit, has overcome disadvantages of complicated manufacturing process for the traditional excitation amplifier.The application shows the energy-saving excitation amplifier can achieve stepless dimming for high pressure sodium lamp to good energy-saving effect. The use cost of excitation amplifier is lower as simple production process, so its promotional value is great.

KEYWORD: switching power amplifiers; quasi-PID control method; single neuron; adaptive control method; protective relay test devices ABSTRACT: Protective relay test devices (PRTDs) are indispensable tools for testing protective relays and other security and automatic equipment. To promote test qualities, it is required that modern PRTDs be able to adapt to different loads, time-variant system parameters, random disturbances and fault waveforms containing various frequency components and nonperiodic components so as to ensure the accuracies of output waveforms, and this is directly determined by the performance of power amplifiers (PAs) adopted by PRTDs. Linear PAs (LPAs) are generally the preference choices, considering the difficulties in controlling the tracking accuracies of switching PAs (SPAs). Except that, however, SPAs have many advantages over LPAs. This paper presents an effective control method, named single-neuron quasi-PID control method, to improve the tracking accuracies of SPAs to make their applications in modern PRTDs feasible. Experiments show that the mean square error of this control method is less than 0.15%, meaning that the accuracy requirement of modern PRTDs is satisfactorily fulfilled. And the computational complexity of this control method is small and so it is very suitable for realization on lowperformance microprocessors.