Digital power chipset optimizes dead time to deliver highest efficiency

Texas Instruments (TI) has introduced the first power management chipset with intelligent digital control and a 'unique' body-diode sensing feature to optimize secondary-side synchronous rectification in next-generation AC/DC and isolated DC-DC power supplies. The UCD3138A digital controller and UCD7138 low-side gate driver improve system efficiency and cut synchronous rectification MOSFET voltage stress in half compared to other digital-power solutions. Accurate control of dead time in the synchronous rectifiers helps minimize power losses and reduces the risk of MOSFET failure. The UCD3138A and UCD7138 chipset use body-diode voltage information in fast digital control algorithms to dynamically optimize dead-time and compensate for power-stage component variations without calibration or screening during mass production. This helps telecom and server end-equipment manufacturers more easily bring to market energy-efficient 80 PLUS Titanium-grade power supplies, which saves energy costs to information technology service providers. Key features : 1 - Intelligent diode voltage sensing optimizes dead time: Adjusting timing for minimal diode conduction increases efficiency and reliability, while eliminating the signal-to-noise ratio challenges of traditional MOSFET VDS ON sensing devices. 2 - High peak current supports wide load range: The UCD7138’s asymmetrical, rail-to-rail 4-A source and 6-A sink peak-current drive supports load range of a few-hundred watts to a kilowatt where multiple paralleled FETs are used. 3 - Compact solution enables fast, efficient switching: A 3mm x 3mm QFN package reduces board space as well as parasitic inductances when placed alongside the synchronous rectifier MOSFETs. 4 - and fast rise / fall times with minimized tolerances in UCD7138 enable extremely high frequencies. Along with the chipset, TI has also recently released a new solution for lower-power AC/DC fly-back converters. The UCC24630 synchronous rectifier controller delivers the highest efficiency with low sensitivity to board layout and MOSFET package parasitics. Auto low-power detection and 110-uA standby current also allow designers to easily achieve ultra-low standby power consumption. Tools and support can quickly develop and debug applications with TI’s Code Composer Studio (CCS) integrated development environment (IDE) or refer to the TI Designs 340W digital controlled LLC resonant half-bridge DC-DC power conversion reference design, says the company.