The power management IC (PMIC) is often a vital part of the lower-voltage DC subsystem, as circuits have multiple power rails with tight individual specifications as well as mandated relationships among them. It’s one thing to develop needed low-voltage DC rails via DC/DC converters or regulators, but there’s also a need to manage these power […]
FAQ
GaN FETs boost efficiency in electric vehicle chargers
The role gallium-nitride FETs play in the design of an EV charging circuit help illustrate how these wide-bandgap semiconductors facilitate energy efficiency. FENG QI, TRANSPHORM THE PHASE-SHIFT FULL BRIDGE (PSFB) is a classic topology for applications that must accommodate a wide range of operating voltages, as with battery chargers. A PSFB converter generally uses four […]
Optimizing the energy efficiency of converters and controllers
Here’s how to evaluate energy efficiency associated with components that make up widely used power conversion circuitry. FRANK DE STASI, MATHEW JACOB, TEXAS INSTRUMENTS INC. IN SOME WAYS, selecting a module, converter or controller for power conversion resembles deciding whether to take a flight, board a train, or drive from point A to B. Once […]
Prepare for IEC 62368-1, the new hazard-based safety standard
Get ready to evaluate safety measures in a different way. JEFF SCHNABEL, CUI THE FAMILIAR 60950-1 AND 60065 SAFETY STANDARDS for information and communication technology (ICT) and audio-visual (AV) equipment are being phased out in 2020, in favor of a single, harmonized standard based on a more modern approach to safety and testing. OEMs must […]
Transforming ac to dc without transformers
Substituting special capacitors for transformers helps realize ac-to-dc power supplies that are both efficient and compact. JEFF SORENSEN, HELIX SEMICONDUCTORS POWER SUPPLIES that convert ac to dc have been a part of nearly every electronics-based product since the popularization of the vacuum tube radio. While the voltage levels have changed, the conversion process has always […]
Power-supply overvoltage protection, Part 2: Clamps
Part 1 of this FAQ discussed the context of overvoltage protection and crowbars which provide OVP. This part will look at clamps for OVP use. Q: What does the clamp do? A: A clamp conducts just-enough current to maintain the voltage across it at a safe, desired value when the transient is above the clamp’s […]
Power-supply overvoltage protection, Part 1: Crowbars
Engineers who deal with power supplies (as most eventually do) often see the circuit-protection terms “crowbar” and “clamp.” No, there are no references to items purchased at the local hardware store, but they are essential “hardware” elements, meaning autonomous circuit components and functions with no related software. They are used to provide protection to a […]
FAQ: Piezoelectric motors, Part 2: drive circuits
Unlike better-known electromagnetic motors, the widely used piezoelectric-based motor/actuator provides precise, repeatable linear motion over short distances, and requires a voltage drive rather than a current drive. Part 1 of this FAQ looked at the moving piezoelectric element of the actuator. Part 2 looks at their drive requirements, which are very different than those of […]
FAQ: Piezoelectric motors, Part 1: actuators
Unlike better-known electromagnetic motors, the widely used piezoelectric-based motor/actuator provides precise, repeatable linear motion over short distances, and requires a voltage drive rather than a current drive. When we think “motor”, we usually think of rotating motion or perhaps a special “linear motor” which is a rotary motor which has been rolled out flat. To […]
Optocouplers, Part 2: Parameters and applications
Part 1 of this FAQ explored the basics of the optocoupler. This part looks at key parameters and some application examples. Q: What are the primary factors used when assessing an optocoupler? A: While there are many important factors, there are several which are noteworthy: isolation, current-transfer ratio (CTR), linearity (for analog use), and speed. […]