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...

This is the final part of a three-part series discussing measurement methods for high-frequency, common-mode (CM) current, voltage, and impedance using a flyback converter. Part I covered the basic principles of radiated EMI and the traditional method for measuring CM current in a flyback converter topology. Part II explored a ferrite bead solution for CM current measurement errors and how to obta...

This is the second part of a three-part series discussing measurement methods for high-frequency, common-mode (CM) current, voltage, and impedance using a flyback converter. Part I covered the basics of radiated EMI and the traditional method for measuring CM current in a flyback converter topology. Part II will propose a solution to common errors when measuring CM current, and then it will demons...

The low-carbon era is leading the development trend for smaller and highly efficient chips. First, switching power supplies replaced linear power supplies in the 1980s; now, the efficiency of power supplies has significantly improved while the overall solution size has been reduced. When considering consumer requirements for portability, switching power supplies continue to become more and more ad...

To meet the increasingly stringent requirements for environmentally friendly solutions, MPS’s AC/DC power supply products utilize advanced technologies to enhance performance and achieve energy conservation. This article is the second in a two-part series to discuss trend-setting AC/DC solutions. Part I served as an introduction for the carbon-free era and the problems that designers face with tr...

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...

To obtain an accurate EMI analysis when modeling power electronics, it is crucial to measure the impedance on the noise source and propagation path. For radiated EMI, the corresponding frequency band is typically between 30MHz and 1GHz. Due to the high frequency, it can be difficult to measure parameters such as voltage, current, and impedance. This article is the first part of a three-part serie...

MPS is committed to providing users with a variety of simulation solutions, including SIMPLIS models, SPICE models, DC/DC converter design models, and Virtual Bench Pro. The easy-to-use Design Assistant is the most popular tool provided by MPS, and its demand continues to grow each year. Figure 1 shows the annual growth of how often our Design Assistant is requested and utilized. In partic...

The flyback power supply is one of the most commonly used topologies. Typically, the transformer’s leakage inductance causes primary-side ringing, which generates voltage spikes that damage the MOSFET. It is essential to design the transformer and MOSFET components to control ringing. MPS has introduced an RCD clamp circuit design strategy to reduce leakage inductance. This circuit is described in...

As modern devices become smarter and more customizable, consumers are also demanding that they be smaller and more powerful. This has driven demand for technology that can manage thermals with ever-higher power densities as processing power increases. MPS is innovating and creating highly integrated converters and controllers with cutting-edge efficiency and power density. By integrating the entir...

This article is the second part of a two-part series exploring how to design an active-clamp forward controller for PoE-bt applications. Part I covered PoE applications, as well as the basics for forward converter topologies and active clamps. Part II will review secondary-side synchronous rectification MOSFETs, secondary spike absorption circuits, and efficiency verification processes for PoE-bt ...

When compared to traditional AC power supply modes, power over Ethernet (PoE) power supplies can simultaneously supply power and transmit data through an existing Ethernet cable. By integrating the power supply and data cables, PoE applications are cost-effective and provide flexible installation. PoE solutions are rapidly growing in popularity across multiple industries as applications continue t...

Flyback power converters are currently some of the most common converter topologies around. This is due to the simplicity of their design and the competitive size/cost/efficiency ratio their can deliver, especially in the mid-level power range (2W to 100W). Like any converter topology, a flyback converter is composed of a power path and a control path. The power path is responsible for the conver...