Texas Instruments (TI) today announced the industry's first power management chipset with intelligent digital control and unique body diode sensing to optimize secondary side synchronous rectification in next-generation AC/DC power supplies. The UCD3138A digital controller and the UCD7138 low-side gate driver improve system efficiency by halving the synchronous rectified MOSFET voltage stress compared to other digital power solutions.

Precise control of dead time in the synchronous rectifier minimizes power loss while reducing the risk of MOSFET power failure. The UCD3138A and UCD7138 chipsets use body diode voltage information in fast digital control algorithms to dynamically optimize dead time and compensate for power stage component variations, eliminating the need for calibration or screening in mass production. This can help server and telecom equipment vendors accelerate time-to-market for 80 PLUS Titanium Gold certified power supplies while helping IT service providers save energy costs.

Key features and benefits of the UCD3138A and UCD7138:

Smart Diode Voltage Sensing Optimizes Dead Time: Improves efficiency and reliability by more accurately detecting the conduction of parasitic diodes in synchronous rectifiers while eliminating the signal-to-noise ratio of traditional MOSFET VDS ON sensing devices.

High peak current support for a wide load range: UCD7138's asymmetrical, rail-to-rail 4 A supply current and 6 A peak sink current drive can support load ranges from a few hundred watts to one kilowatt with multiple parallel FETs .

• Compact solution for fast, efficient switching: A single 3 mm x 3 mm quad flat no-lead (QFN) package reduces board space and reduces the amount of wiring that is placed next to the synchronous rectifier MOSFET Parasitic inductance.

• Efficient operation at frequencies up to 2 MHz: Hardware peripherals in the UCD3138A and 14 ns propagation delay, fast rise/fall times, and minimized tolerance in the UCD7138 enable extremely high frequencies.

　In conjunction with this chipset, TI has also recently released a new lower power AC/DC Flyback converter. TI's UCC24630 synchronous rectification controller provides the highest efficiency and low sensitivity to board layout and MOSFET package parasitics. In addition, automatic low-power detection and 110μA standby current also allow designers to easily achieve ultra-low standby power consumption.

Tools and support

Designers will be able to quickly develop and debug applications using TI's Code Composer StudioTM (CCS) integrated development environment (IDE) or TI's Designs 340 W digitally controlled LLC resonant half-bridge DC/DC power conversion reference design .

Availability

Currently, UCD3138A and UCD7138 devices are available through TI Store and the company's authorized distribution network. The UCD7138 MOSFET driver is available in a 6-pin QFN package. The UCD3138A digital controller is available in a 40-pin QFN package.