Numerical Modeling of ESD-Simulators

ESD generators are widely used for testing the robustness of electronic equipment against human electrostatic discharge via small metal pieces (e.g. key). Presently the IEC 61000-4-2 ESD standard is hotly discussed to improve test result reproducibility. This paper numerically analyzes an ESD simulator and relates its construction parameters to discharge current and field parameters. It uses FDTD method and models the relay (contact mode discharge) as a material with time dependent conductivity. The process is broken down into a charging phase and a stabilization phase until the electrostatic conditions are reached. Then the conductivity of the relay is changed and the discharge process is simulated. A self-developed code is used to simulate the model. The simulation discharge current, measured ESD simulator\u27s current and IEC reference discharge current are compared Some design choices of the generator are simulated

Searching for the Sunk Cost Fallacy

We seek to isolate in the laboratory factors that encourage and discourage the sunk cost fallacy. Subjects play a computer game in which they decide whether to keep digging for treasure on an island or to sink a cost (which will turn out to be either high or low) to move to another island. The research hypothesis is that subjects will stay longer on islands that were more costly to find. Nine treatment variables are considered, e.g. alternative visual displays, whether the treasure value of an island is shown on arrival or discovered by trial and error, and alternative parameters for sunk costs. The data reveal a surprisingly small and erratic sunk cost effect that is generally insensitive to the proposed psychological drivers.sunk cost fallacy, experimental economics

Searching for the Sunk Cost Fallacy

We seek to isolate in the laboratory factors that encourage and discourage the sunk cost fallacy. Subjects play a computer game in which they decide whether to keep digging for treasure on an island or to sink a cost (which will turn out to be either high or low) to move to another island. The research hypothesis is that subjects will stay longer on islands that were more costly to find. Nine treatment variables are considered, e.g. alternative visual displays, whether the treasure value of an island is shown on arrival or discovered by trial and error, and alternative parameters for sunk costs. The data reveal a surprisingly small and erratic sunk cost effect that is generally insensitive to the proposed psychological drivers.sunk cost fallacy

A Three-Dimensional FDTD Subgridding Method with Separate Spatial and Temporal Subgridding Interfaces

The idea of separating the spatial and temporal subgridding interfaces is introduced in this paper. Based on this idea, the spatial and temporal subgridding algorithms can be developed and analyzed separately. The spatial algorithm was given in the previous paper. In this paper, the temporal subgridding algorithm is described and the stability is illustrated by the analytical formulation of a one-dimensional model. An FDTD code that combines the spatial and temporal subgridding algorithms is implemented. Numerical test models are calculated to show the stability and accuracy of the proposed method

A Three-Dimensional FDTD Subgridding Algorithm with Separated Temporal and Spatial Interfaces and Related Stability Analysis

A finite-different time-domain subgrid algorithm locally refines the mesh at regions requiring higher resolution. A novel separation of spatial and temporal subgridding interfaces is presented that allows implementing a novel spatial subgridding method and investigating the stability of each subalgorithm individually. Details are given for a spatial subgridding algorithm having a 1:3 mesh ratio. In the spatial subgridding algorithm, the fine-mesh is constructed with a recessed interface and the interpolation scheme is designed to be symmetric to maintain the stability of the update process. The stability of the spatial subgridding algorithm is analyzed with a matrix method. Numerical examples showing stability and accuracy are provided

ESD Currents and Fields on the VCP and the HCP Modeled using Quasi-Static Approximations

The horizontal coupling plane (HCP) and the vertical coupling plane (VCP) are essential elements of the standardized electrostatic discharge (ESD) test. They are used for testing the robustness of equipment against indirect (nearby) discharges. This article analyzed the current and the fields on the HCP and the VCP using plane wave, transmission line, quasi-static theory. The objective is to illustrate the dominating physical processes on these planes. The work is based on measurements of the transient currents and fields using broadband sensors

FDTD Method Capable of Attaching Rectangular Domains

A finite-difference time-domain (FDTD) method capable of attaching rectangular computational domains is proposed herein. The aim of this approach is to reduce the size of computational domain according to the geometry of the modeled structure so as to reduce the simulation time with keeping precision of the result in an acceptable range. A multigrid algorithm is applied on the attaching interface between two rectangular domains so that different resolution can be achieved in different domains

A Three-Dimensional FDTD Subgridding Algorithm Based on Interpolation of Current Density

A three-dimensional subgridding algorithm for the finite difference time domain (FDTD) method is proposed in this paper. The method is based on interpolation of electric and magnetic current densities. The coarse-fine mesh ratio can be either 1:2 or 1:3. Results of a test model utilizing a lossless cavity excited with a dipole show no tendency of instability after 500000 time steps. The reflection in time domain at the subgridding interface was calculated to test the accuracy of the subgridding algorithm

ESD Susceptibility Characterization of an EUT by Using 3D ESD Scanning System

Electrostatic discharges (ESD) can lead to soft-errors (e.g., bit-errors, wrong resets etc.) in digital electronics. The use of lower threshold voltages and faster I/O increases the sensitivity. In the analysis of ESD problems, an exact knowledge of the affected pins and nets is essential for an optimal solution. In this paper, a three dimensional ESD scanning system which has been developed to record the ESD susceptibility map for printed circuit board is presented and the mechanisms that the ESD event couples into the digital devices is studied. The ESD susceptibility of a fast CMOS EUT is characterized by generating the susceptibility map of the EUT. A series of measurements of the noise coupled into a sensitive trace and pin during an ESD soft error event are presented

The PCB Level ESD Immunity Study by Using 3 Dimension ESD Scan System

The use of high-speed logic makes modern electronic systems highly susceptible to electrostatic discharge (ESD). Because of their wider bandwidth, faster digital devices are more susceptible to high frequency ESD transient fields. In the analysis of ESD problems, an exact knowledge of the affected PINs and nets is essential for an optimal solution. A three dimensional ESD scanning system, which has been developed to record the ESD susceptibility map for a printed circuit board, is presented, and the mechanisms that the ESD event couples into the digital devices is studied