Learn More
—This paper discusses the presence of steady-state limit cycles in digitally controlled pulse-width modulation (PWM) converters, and suggests conditions on the control law and the quantization resolution for their elimination. It then introduces single-phase and multi-phase controlled digital dither as a means of increasing the effective resolution of(More)
—This paper develops the architecture of a digital PWM controller for application in multiphase voltage regulation modules (VRMs). In this context, passive current sharing and VRM transient response with nonzero controller delay are analyzed. A scheme for sensing a combination of the VRM output voltage and output current with a single low-resolution window(More)
BACKGROUND The growing use of transcranial electric and magnetic (EM) brain stimulation in basic research and in clinical applications necessitates a clear understanding of what constitutes the dose of EM stimulation and how it should be reported. METHODS This paper provides fundamental definitions and principles for reporting of dose that encompass any(More)
BACKGROUND Various transcranial magnetic stimulation (TMS) coil designs are available or have been proposed. However, key coil characteristics such as electric field focality and attenuation in depth have not been adequately compared. Knowledge of the coil focality and depth characteristics can help TMS researchers and clinicians with coil selection and(More)
—This paper describes a dual-mode digitally controlled buck converter IC for cellular phone applications. An architecture employing internal power management is introduced to ensure voltage compatibility between a single-cell lithium-ion battery voltage and a low-voltage integrated circuit technology. Special purpose analog and digital interface elements(More)
—A consistent framework for load-line regulation design is presented, applicable to microprocessor voltage regulators (VRs) using either electrolytic or ceramic output capacitors. With conventional feedback control, the loop bandwidth is limited by stability constraints linked to the switching frequency. The output capacitor has to be chosen sufficiently(More)
We present the first computational study comparing the electric field induced by various electroconvulsive therapy (ECT) and magnetic seizure therapy (MST) paradigms. Four ECT electrode configurations (bilateral, bifrontal, right unilateral, and focal electrically administered seizure therapy) and three MST coil configurations (circular, cap, and double(More)
In this article, we review the parameters that define the electroconvulsive therapy (ECT) electrical stimulus and discuss their biophysical roles. We also present the summary metrics of charge and energy that are conventionally used to describe the dose of ECT and the rules commonly deployed to individualize the dose for each patient. We then highlight the(More)
We present a quantitative comparison of two metrics-neural stimulation strength and focality-in electrocon-vulsive therapy (ECT) and magnetic seizure therapy (MST) using finite-element method (FEM) simulation in a spherical head model. Five stimulation modalities were modeled, including bilateral ECT, unilateral ECT, focal electrically administered seizure(More)