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The SIMCOM SIM7070G initially appears to be a simple device: connect it over UART, send AT commands, register on the network, and transmit data to a server. On a laboratory bench, the first HTTP request can often be completed relatively quickly. The real problems begin later, when the device must operate autonomously for days or weeks. The network may disappear temporarily, the modem may send asynchronous URC messages, an HTTP session may close unexpectedly, and commands such

In this test, we decided to take a different approach and evaluate a SEPIC converter that anyone can easily buy from Amazon or AliExpress. The idea was simple: instead of a carefully designed lab prototype, we wanted to see how a typical off-the-shelf module behaves in a real EMC environment. The converter was tested against the CISPR 25 standard, which is considered one of the stricter EMC standards, especially for automotive applications. In practice, many electronic device

First, the measurement setup for evaluating common-mode and differential-mode currents is defined - Common-mode current is measured using a current probe clamped around both the positive and negative conductors simultaneously. Differential-mode current is evaluated by measuring each conductor individually (positive and negative). This is the measurement setup used for current testing. CISPR 25 Class 5 limits were applied to assess the feasibility of optimizing the device and

A recurring observation during EMC validation is straightforward: if conducted emissions fail, radiated emissions will also fail in most cases. The root cause is identical — excessive high-frequency current loops and poor control of switching node parasitic. This case focuses on a SEPIC-based charger that failed conducted emission limits per CISPR 11. Figure 1: Schematic 1. Hot Loop Analysis of the DC/DC Stage The dominant emission source in a SEPIC converter is the high di/d

When we approach the task of analyzing EMC redesign case studies, it is essential to maintain a clear and methodical perspective. Electromagnetic compatibility (EMC) is a critical aspect in the development of industrial and automotive electronics, where ensuring devices operate without mutual interference is paramount. By carefully examining case studies, we can extract valuable lessons that help improve design processes, reduce time to market, and ensure compliance with stri

When developing complex electronic products, especially for industrial and automotive applications, ensuring electromagnetic compatibility (EMC) is crucial. EMC compliance guarantees that devices operate correctly without causing or suffering from electromagnetic interference (EMI). Achieving this requires careful attention to printed circuit board (PCB) design, as the PCB layout significantly influences the electromagnetic behavior of the final product. In this article, we w

When developing complex electronic products, especially in industrial and automotive sectors, obtaining precise and reliable quotes for printed circuit board (PCB) design is essential. Accurate quotes help in budgeting, planning, and ensuring that the final product meets all technical and regulatory requirements. In this article, we will explore the key factors that influence PCB design quotes, how to prepare your project details for quoting, and practical tips to communicate

Task Overview The goal is to select the most suitable type of rechargeable battery for a pack rated at approximately 24 V with a capacity of about 10 Ah . The battery will be used very infrequently to power a DC motor: the motor is started roughly once every few months and runs for 15–20 minutes , after which the battery remains idle with no load for long periods . Key requirements are high energy density and long service life , with a strong emphasis on retaining charge a

Introduction A field failure investigation revealed a recurring and costly issue: a Wi-Fi module and the main MCU were burning out intermittently in a production device. The failures were not random. They were triggered by external disturbances, particularly electrostatic discharge (ESD) events near a solenoid cable. Both components were powered from independent low-voltage rails (3.3V domain), yet both were failing under transient stress conditions. This case study describes

Modern PCB design must take electromagnetic compatibility (EMC) into account from the very beginning. Below is a comprehensive set of rules and recommendations aimed at reducing electromagnetic interference (EMI) and improving immunity to it. The guidelines are organized by topic — from high-power supplies and high-speed digital signals to sensitive analog circuits, RF designs, and ESD protection measures. Each rule includes a clear title, a detailed explanation with the unde