Application Notes

The ever-increasing demand for ESD protection in today's fast-growing mobile device market has led Diotec to
focus on providing circuit protection solutions.

Whether the application is portable electronics, a USB data port or a CAN bus in the automotive industry,
Diotec's portfolio of overvoltage and overcurrent protection products provides a solution for the application.

This Application Note will deep dive into this topic showing you conditions, standards, testing results, common protection methods and of course a selection of eligible Diotec products which get the job done.

The heart of any industrial or domestic control device is either a microcontroller, a PLC (Programmable Logic Controller) or an IPC (Industrial PC). It handles the data processing, logic control, and interfacing. The latter includes digital inputs and outputs for status and PWM signals, switches or relays. Analog inputs measure variables such as temperature, brightness or frequency, while the outputs provide signal voltages or currents. Communication with other devices works via special interfaces such as Profibus, Profinet, EtherNet/IP, CANopen, Modbus or KNX. The power supply runs on typical input voltages of 24 VDC, 48 VDC or 110/230 VAC; sometimes, communication data are transferred via the power line itself.

Diotec provides dedicated semiconductor components acting between the microcomputer device and its surrounding. This Application Note introduces it.

The so-called “Arrhenius law” states — in short — that every 10 K increase in temperature reduces the service life of a physical device by 50%. Thermal considerations are therefore essential for power semiconductors. This application note shows how to correctly measure and calculate the junction temperature, provides tips on the correct application of thermal paste, and explains how components must be mounted correctly on the heat sink.

During construction of solar modules, single cells are switched in series to so called “strings” to achieve higher system voltages.

If one or more cells are shaded (e.g. by branches of trees, antennas, etc.), the affected solar cells are no more acting like a current source, but as power consumers. Non-shaded cells are delivering further current through them, generating high power losses. “Hot spots” may occur and even cell breakdowns.

To overcome this problem, bypass diodes are switched parallel to every single or some combined cells, bypassing current flow across the darkened strings.

Like every semiconductor device, also bypass diodes have got a certain leakage current, which in normal mode of operation reduces the current supplied by the cells and therefore decreases efficiency of the solar module. Therefore leakage current especially at higher temperatures (full sun irradiation!) should be as low as possible. Compared to that, partly shading of modules is only an extreme operation mode which should be completely avoided or at least occurs only during short time periods. For this mode of operation, low forward losses are desirable.

Finally, the bypass diode has to be rugged against overvoltage spikes. Such spikes may occur during assembly of the system, if
e. g. current conducting cables are interrupted, or during operation, caused by lightning etc.

You will find more information in our Application Note Solar Bypass Diodes - you can download the PDF down below.

This board is used to demonstrate the use of the Diotec DI280N10TL in a high-power delivery unit. It is capable of switching up to 80 A at 48 V in both directions. This makes it ideally suited for battery systems which need not only to supply power, but also to receive during the charging cycle. Current, Voltage, temperature and operating mode is displayed on an OLED display. Various other Diotec parts such as LDOs, small signal MOSFETs, Rectifier Diodes, Zeners and ESD protection diodes is also used on this module.

This board is used to demonstrate the functionality of the LDI55-ADEEN linear regulator. It has wide input range up to 50V, low-dropout (LDO) voltage regulators with enable function and provides up to 1A of output current. Only two small ceramic capacitors are needed to implement the linear regulator solution. The features of low quiescent current as low as 3 µA to 5µA and almost 0.5 µA disable current is ideal for powering the battery equipment to a longer service. Simple device measurements such as line and load regulation, dropout, can be demonstrated with just a single voltage source, a voltmeter, an ammeter, and load resistor.

The BMS ensures the safety, longevity, and optimal performance of the battery in the e-vehicle. It helps extend the electric range to 500 kilometers and beyond in modern vehicles. This means that many vacation areas in Italy can already be reached without charging from southern Germany. Typically, the BMS consists of a battery management unit (BMU), sensors, a power stage, and a battery disconnect unit (BDU). The BMU monitors the battery's voltage, current, temperature, and state of charge, while the sensors provide data to the BMU. It also controls the charging process, either through a high-power DC connection or the on-board charger (OBC). The BDU disconnects the high-voltage battery from the vehicle when it is not in use. Diotec's latest application note addresses discrete semiconductor solutions for BMS, such as power MOSFETs, load dump protection, TVS diodes, Schottky, Zener, ESD diodes, and voltage regulators.

An on-board charger for electric vehicles is a device that is integrated into the vehicle and charges the battery when no charging station or wall box is available.
It works with alternating current and converts it into slip current, which charges the battery. The charger can either be built into the vehicle itself or added as an aftermarket accessory. The voltage and power range of a charger can vary depending on the make and model of the electric vehicle. However, most on-board chargers for e-vehicles operate on a voltage of 100-240 volts AC and have a power range of 3-11 kilowatts (kW).