Field Effect Rectifier Diodes (FERD)

Featured Product from Digi-Key Electronics


STMicroelectronics’ FERD family offers a unique trade-off between low forward voltage drop (VF) and low leakage current (IR) that allows designers of equipment, such as battery chargers and notebook adapters, to meet the most stringent energy-efficiency standard requirements without the expense of using synchronous rectification techniques. Standards such as Energy Star 6.0 test the limits of what can be achieved with conventional Schottky diodes in battery chargers and notebook adapters. Synchronous rectification provides superior performance but at significantly higher cost. The ST FERD family provides an attractive alternative as it meets the efficiency levels required by the energy-savings standards applicable to off-line switch mode power supplies (SMPS) while costing about 30% less than a synchronous rectification kit.

Based on patented ST FERD technology, these diodes are available in the ranges from 15 A to 2 x 30 A and from 45 V to 60 V and achieve the best-in-class VF/IR for a given silicon surface area. For example, a 30 A device using FERD technology features a forward voltage drop reduced by about 140 mV compared to a conventional 30 A Schottky diode, without increasing the leakage current. With its lower forward voltage drop and better-managed leakage current, the ST technology increases the current that can flow for a given package power-dissipation capability. Benefits include faster charging of smartphones and tablets, reduced notebook-charger size and weight, and increased lifetime of the equipment as the FERD operates at a lower temperature. The FERD technology is also well suited for applications and systems in other segments, such as freewheeling or reverse battery protection in automotive applications; OR-ing in telecom power supplies; or rectification in industrial systems, and could be offered in FERD devices with various voltage and current ratings to support the needs of the different markets. Twelve FERD devices are currently available, housed in TO-220AB, D²PAK, and PowerFLAT™ 5 x 6.

Features    
  • Advanced rectifier proprietary process
  • Stable leakage current over reverse voltage
 
  • Low forward voltage drop
  • High-frequency operation
Applications    
  • Industrial power
    • Factory automation
    • Tooling chargers
  • DC/DC converters
  • SMPS
  • USB chargers
 
  • Auxiliary power
    • Server and telecom power
    • Air conditioning
    • Home appliances
    • UPS