By the application of well-known circuit analysis techniques, this paper develops an intuitive approach to model the steady state regime of the three DC/DC power converters’ basic topologies (buck, boost and buck-boost). The developed approach can be considered new, realistic, accurate, general and practical. The approach is new because it is not present in the literature; realistic because it ...

This paper summarizes recent research at the author’s laboratory into power management circuitry, including: (1) Envelope-tracking power supplies for base station power amplifiers, (2) Digital PWM generator circuitry, (3) Spreadspectrum clocking for EMI reduction in digitally-controlled power supplies, (4) High-efficiency coupled-inductor DC-DC converters with fast response and low ripple, and ...

The realization of line and load regulation in switchedcapacitor (SC)-based converters is discussed. A duty-cycle control is based on partial charging of the capacitors in the circuit. The influence on the efficiency is pointed out. The use of inductors in SC-based converters is discussed.

The ac-dc transfer standard is one of the basic electrical standards, by which the ac voltage and ac current are deduced from their dc counterparts in the frequency range between 10 Hz and 1 MHz [1,2]. The dc voltage standards are established using a Josephson voltage standard with uncertainty better than 10-7 [3-5]. The ac voltage standard in the frequency range 10 Hz to 1 MHz are derived from...

As CMOS technology is scaling down, the effect of voltage drop in power distribution network is becoming more prominent. Such voltage drops on power lines in a clock network introduces significant amount of skew, thereby degrading the signal integrity. With rising power consumption and decreasing supply voltages, the supply current will increase in future devices. The IR drops can be reduced by...

The operational limitations of the voltage and current transfer ratios are inherent to conventional current source converters (CSCs) and voltage source converters (VSCs), which prompts the multiple-stage power conversion solution for applications that demand a wide voltage or current transfer ratio. In response to the undesired characteristics of the multiple-stage solution, such as augmented c...

BACKGROUND Mild cognitive impairment (MCI) may represent an early stage of dementia conferring a particularly high annual risk of 15-20% of conversion to Alzheimer's disease (AD). Recent findings suggest that not only gray matter (GM) loss but also a decline in white matter (WM) integrity may be associated with imminent conversion from MCI to AD. OBJECTIVE In this study we used Voxel-based mo...

It is well known that undesirable harmonic line currents may be generated during a transformer-rectifier combination. The rectification of AC power to DC power itself may in general produce undesirable current harmonics. These non-linear loads cause severe current harmonics that may not be tolerated by either a shutdown of the device or unacceptable powering of the devices. The great majority o...

This topic discusses the trade-offs between fixed-frequency pulse-width modulation (PWM) and pulsefrequency modulation (PFM) for portable DC/DC converter applications. PWM converters offer the benefit of predictable operating frequency, which may simplify the design of circuitry that suppresses electromagnetic interference (EMI). They also offer low output ripple characteristics and high effici...

T RADITIONAL designs of high-speed CMOS analogto-digital (A/D) converters have used parallel (flash) architectures [1]–[13]. While flash architectures usually yield the highest throughput rate, they tend to require large silicon. areas because of the many comparators required. An important objective is the realization of high-speed A/D converters in much less area than that required by flash co...