Raul Fizesan

Simulation for power integrity to design a PCB for an optimum cost

One of the biggest design challenges today is to properly design, manufacture, simulate and validate a Power Distribution Network (PDN) in systems with increasing speed, power dissipation and density. PDN are typically comprised of capacitors networks that have several types of capacitors and values to obtain target impedance over the required frequency range for the power/ground planes on PCBs. Capacitors provide a temporary source of localized energy for instantaneous current demands from an IC, and a low-impedance return path for high frequency noise. This paper propose a simulation test for a 4 layer PCB, with power/ground planes, to evaluate the effectiveness and importance of decoupling capacitors, using tools and methodologies to determine the important factors like performance, cost and board area.

Packaging and thermal analysis of power electronics modules

The Intermediate Data Format (IDF) is a specification designed to provide a neutral representation for exchanging printed circuit assembly (PCA) data among mechanical design (MCAD), PCA layout (ECAD), and physical design analysis (MCAE) applications. Powerful analysis software, like Ansys, Maxwell, Semcad, Altium Designer or SolidWorks – CircuitWorks, can import the idf files and use the model for electromagnetic or thermal analysis. The information can also be used for a mechanical approach point of view. The paper will present a combined analysis – starting from electrical design, then the 3D model, thermal and mechanical approach of the PCB Layout for a relative humidity and temperature controller as a case study.

Power integrity design tips to minimize the effects of mounting inductance of decoupling capacitors

The simulation and the analysis of a power distribution network (PDN), termed power integrity (PI), are performed in the frequency domain and primarily involve analyzing the power and ground planes and the decoupling capacitors. The capacitors provide a temporary source of localized energy for instantaneous current demands from a IC, and a low-impedance return path for high frequency noise. Capacitors need to be close to the device to perform the decoupling function. Efficient energy transfer from the capacitor to the integrated circuit requires placement of the capacitor at a fraction of a quarter wavelengths of the ICs power pins. The purpose of this paper is to simulate a four layer PCB, with power/ground planes, to evaluate the effectiveness and the importance of decoupling capacitors placement, using tools and methodologies to determine the important factors like performance, cost and board area.

Power integrity analysis and bypass capacitor selection using FDM on a printed circuit board

Power delivery is a major challenge in present-day systems. This challenge is expected to increase in the next decade as systems become smaller and new materials are introduced into packages and boards. Planes form an integral part of a power delivery system (PDS). They provide charge to the switching circuits at high frequencies and support return current of the signal lines. Planes pairs are widely used on high-speed printed circuit boards. Planes are capacitive at low frequencies and become inductive at high frequencies. Since lateral dimensions of planes are multiple of λ, they behave as spatially distribute systems and resonate at higher frequencies due to the reflections from the open edges. The goal of this article is to approach an efficient numerical approach based on the finite difference method (FDM) to model the power/ground plane in a printed circuit board in frequency domain and how to choose decoupling capacitors for PDSs. The power system should meet the target impedance across a broad frequency range from direct current, up to the highest frequency of interest. To maintain the impedance of a PDS below a specified level, multiple decoupling capacitors are placed at different levels of the power grid hierarchy.

Pre-layout power integrity analysis in the design flow of a PCB

The simulation and the analysis of a power distribution network (PDN), termed power integrity (PI), is performed in the frequency domain and primarily involves analyzing the power and ground planes, the decoupling capacitors and the simultaneous switching noise (SSN). The original layout is modified based on these PI analyses to account for any design flaws arising due to parasitic effects. To avoid an expensive procedure, it is add an additional simulation at the pre-layout stage to catch the major design flaws. These simulations are used to guide the final layout process. There are several commercial tools available to simulate a power distribution network. The goal is to develop a Matlab tool to perform about same functions as the commercial tools do, so it can be used to identify problems prior layout.

MATLab platform to calculate the transfer impedance of power and ground planes

Planes with dielectric layer separation form an integral part of a power delivery network. For parallel plane pairs separated by a uniform dielectric material, are available analytical expressions describing the self and transfer impedances between rectangular ports. The power delivery network should meet the target impedance across a broad frequency range from direct current, up to highest frequency of interest. The focus is power integrity, so we need to characterize primarily the high-frequency resonance peaks. There are several commercial tools available to simulate PDN planes. Our goal is to develop a MATLab platform for calculating the self impedance or the transfer impedance between two ports of a plane pair consisting of power/ground planes, using Greens function for rectangular plane pairs.

Circuit models for power/ground planes on PCBs using SPICE method

Power planes consisting of two parallel conducting planes: power and ground, are widely used on high-speed printed circuit boards. In [1] was presented an efficient numerical approach based on the 2D FDM (finite difference method) to model the power/ground planes on a PCB in frequency domain and how to choose decoupling capacitors for a PDS (Power Delivery System) using a dedicate software. The goal of this paper is to use the same numerical approach based on FDM, to analyze power/ground planes, but the power structure will be modeled using SPICE programs. Using SPICE, power/ground planes of arbitrary shape can be modeled efficiently both in the time-domain and frequency domain, along with the circuit components connected to the planes.

Weekly electronic pills dispenser with circular containers

This paper proposes the improvement of the process of health recovery by using a programmable medication dispenser. We designed and realized an electronic pills dispenser with seven circular containers. The dispenser is realized around PIC18F458 microcontroller which controls all the function of the dispenser. Using a keyboard and an LCD, the user can easily set the hour when the pills will be supplied on a plate. When the time for medication is arrived, a dose of medication is released and an audio alarm is generated. If the patient does not take the dose prescribed by the doctor, an SMS is sent to a phone number.

Mathematical analysis to control power transfer in resonant power converters

This paper aims to present a mathematical analysis method for resonant power converter, in order to control the transfer of power which is transmitted to the load. Starting from the idea that most switching power converters are using the pulse width modulation (PWM) technique to control the switching elements, the paper presents an analysis of the control method that can be applied on such converters and a mathematical analysis of the resonant load that can be found at the output of the circuit. On the other hand, the paper proposes an interactive interface to design and simulate a resonant power converter. The tool can be used by experienced engineers in power converters domain, to properly configure such a circuit, but also by those who are starting to learn and understand how these circuits are working. The tool allows seeing, not just the final values for the components that make the circuit, but also the waveforms form the main components. By doing so, the converters area of operation can be observed, allowing to adjust the design in order to improve the design.

Why the mounting inductance is important in designing a Power Distribution Network

Minimizing the noise in a Power Distribution Network (PDN) is a critical step in Power Integrity (PI) design. The main effort is to keep the PDN impedance under a certain value in a frequency range by using decoupling capacitors, which can be at Printed Circuit Board (PCB) level, in package or in chip. Although you can get the same performance with any type of capacitor for high frequencies, it is important to consider the efficiency of decoupling capacitors in small ceramic casings at the expense of the large enclosures. Each PCB designer faces certain restrictions, including those related to the gauge plate, number of components, signal traces that need to be routed, so he will be able to achieve its goal increasing the effect of certain factors, [16][20][21][22]. The proximity of the capacitor to the chip and to its vias, and also its parasitic (equivalent series inductance and equivalent series resistance) determine the speed at which the capacitor reacts to the change in current. This paper reviews possible solution to minimize the noise in a PDN by answering the question “Why the mounting inductance needs to be minimize in order to have a proper Power Distribution Network (PDN) impedance?”. To answer of this question, will be used a SPICE equivalent circuit of the PDN. This allows both frequency and transient response to be done with SPICE simulation.