An operational amplifier (op amp) is an analog circuit block that takes a differential voltage input and produces a single-ended voltage output. Op amps usually have three terminals: two high-impedance inputs and a low-impedance output port. The inverting input is denoted with a minus (-) sign, and the non-inverting input uses a positive (+) sign. Operational amplifiers work to amplify the voltag...

A voltage regulator is a circuit that creates and maintains a fixed output voltage, irrespective of changes to the input voltage or load conditions. Voltage regulators (VRs) keep the voltages from a power supply within a range that is compatible with the other electrical components. While voltage regulators are most commonly used for DC/DC power conversion, some can perform AC/AC or AC/DC power c...

Although there are various power supply types, this article will focus on Power over Ethernet (PoE) power supplies. In particular, PoE power supplies where the power sourcing equipment (PSE) supplies power to the powered device (PD) terminal equipment through the network cable. Figure 1 shows common PoE power supply equipment, including the PoE switch as well as power-receiving equipment (e.g. wir...

Reliable and affordable energy sources are required to power the economy and meet daily needs. Without these energy sources, economic growth and development stalls. Dependence on foreign sources for energy can also lead to vulnerability to geopolitical conflicts. With ongoing concerns regarding climate change, ensuring energy security has environmental implications as well, with efforts to increas...

When designing a motor control circuit, it is vital to determine how to deliver the high current required to drive the motor. Designers must choose whether to use monolithic integrated circuits that have internal power devices, or gate driver ICs and discrete external power MOSFETs. This article discusses the advantages and disadvantages of each approach and provides guidance on when to choose eit...

Battery-powered applications have become commonplace over the last decade, and such devices require a certain level of protection to ensure safe usage. The battery management system (BMS) monitors the battery and possible fault conditions, preventing the battery from situations in which it can degrade, fade in capacity, or even potentially harm the user or surrounding environment. It is also the r...

When designing a battery management system (BMS), designers can face challenges when obtaining an accurate estimate of the battery’s state-of-charge (SoC), which is the level of a charge a battery has in relation to its capacity. This article is the second of a two-part series discussing SoC estimations. Part I explored the complex application of battery conditions in SoC estimation, as well one ...

With the dramatic improvement in battery performance, applications are increasingly utilizing battery packs to provide energy. In the battery management system (BMS), designers face the challenge of accurately estimating the battery’s state-of-charge (SoC), which is the level of charge a battery has in relation to its capacity. SoC is commonly represented as a percentage between 0% and 100%. A ba...

For the 2022 Beijing Winter Olympics, all Olympic venues used green electricity to promote the goal for carbon neutrality. Green electricity mainly comes from solar photovoltaic and wind power generation. Utilizing more renewable photovoltaic energy is an effective approach to reach the greenhouse gas pollution target by 2030. Photovoltaic cells have many subdivisions of applications, including...

The demand for fast charging has driven the unprecedented evolution of high-density adapters. In practical adapter designs, there are countless implementations of new switching power devices, topologies, and control schemes. With the introduction of these cutting-edge technologies, the power density of adapter products has significantly increased. 1W/cm3 is becoming the common density for high-de...

Li-ion battery charger ICs are devices that regulate battery charging current and voltage, and are commonly used for portable devices, such as cellphones, laptops, and tablets. Compared to other battery chemistries, Li-ion batteries have one of the highest energy densities, provide a higher voltage per cell, can tolerate higher currents, and do not have to be trickle charged when the battery is fu...

The HR1211 is an integrated, multi-mode PFC and current mode LLC controller solution that was designed to meet the power requirements of the fast-charge adapter market. To achieve a simplified peripheral circuit, the HR1211 integrates a high-voltage current source, a safety-certified X-capacitor discharge circuit, and high-voltage drive circuits for PFC and LLC. In addition, a capacitor resistor i...

MPS recently released an integrated, compact gate driver circuit with six power MOSFETs. This article discusses the MP6540 series, including the MP6540A, MP6540H, and the MP6540HA. The MP6540 is a 3-phase, brushless DC (BLDC) motor driver that integrates three half-bridges consisting of six N-channel power MOSFETs. Conventional motor driver architecture combines a motor driver chip and the power ...