Bridgeless PFC Boosts Low-Line Efficiency
Feb 1, 2008
Wide input-voltage range power factor correction (PFC) converters present some of the most difficult component challenges in ac-dc power electronics....
Power Limits Make Hot Swapping More Robust
Jan 1, 2008
You need more than just current limiting to ensure that the hot-swap FET stays within its safe operating area under all operating conditions....
ICs Make Meter Designs Easier, Energy Theft Harder
Oct 1, 2007
Demands for greater functionality, higher reliability and lower cost have driven the development of the latest electronic energy-metering ICs. These devices, which include both system-on-a-chip metering chips and general-purpose microcontrollers with metering-oriented peripherals, target a range of single-phase and three-phase electricity meter applications for residential or commercial use....
Legacy PD Controllers Support PoE Plus Power
Oct 1, 2007
As the IEEE 802.3af standard for Power over Ethernet is superseded by 802.3at, it is possible to implement a PoE Plus-required power level of 30 W, with the aid of an external MOSFET and a controller designed for the older standard....
Controller Monitors ORing FET Current and Voltage
Sep 1, 2007
Power supplies with N+1 redundancy require the use of an ORing diode or FET to isolate the main supply from the output bus in case of failure. Although ORing diodes are easy to use, the power loss they would cause in high-current supplies is usually unacceptable....
Negative Supply Uses Positive Hysteretic Regulator
Aug 1, 2007
Frequently, the use of a hysteretic regulator is preferred because of its simplicity of use and wide input-voltage range. For example, National Semiconductor's LM5007 is a constant-on-time variation of the hysteretic topology, but offers a nearly constant frequency of operation....
Phase Management Raises Interleaved PFC Efficiency
Jul 1, 2007
Whether implemented with discrete components or integrated
within the PFC controller, phase management can
improve light-load efficiency of power supplies to meet
80 PLUS efficiency requirements....
PoE Chips Reach For Higher Power and New Features
Mar 1, 2007
With millions of power-equipped Ethernet ports shipping each year in switches, routers and midspans, power over Ethernet (PoE) is now a mainstream technology...
Electronica Showcases Latest Power Products
Nov 22, 2006
A record 78,000 attendees were reported at the Electronica event held last week in Munich and many power component vendors took advantage of this massive industry gathering to showcase their latest wares. ...
Digital Bus Makes Current Sharing More Robust
Nov 1, 2006
Power supplies in servers, storage and telecom systems often employ redundant topologies. This means that multiple supplies connected in parallel provide...
Shedding Light on HID Ballast Control
Oct 1, 2006
Aided by a new full-bridge controller, a popular electronic HID ballast topology manages lamp operation, while enhancing lamp safety....
Controllers Take On Complex Power Systems
Oct 1, 2006
Point-of-load (POL) power applications continue to inspire the development of more sophisticated power controllers with greater ability to manage power...
Switching Chip Tames Power Peaks
Jul 1, 2006
A variable frequency switching regulator for ac-dc power supplies drives peak loads from a design optimized for lower continuous loads to enable compliance with efficiency mandates....
Gain Equalization Improves Flyback Performance
Jul 1, 2006
In a discontinuous flyback converter, the gain of the output current is a function of the control voltage. A constant gain can be provided by compensating circuitry, which improves control-loop stability....
