National Semiconductor Introduces Industry’s First 20V Synchronous Buck Controller to Integrate Key Four Features

A new addition to National’s PowerWise® energy-efficient product family, the LM27402’s advanced features make it the industry’s most feature-rich 20V synchronous buck controller. Until today, point-of-load controllers have incorporated one or two complex features, such as a wide input voltage range, integrated high-current gate drivers with adaptive dead-time, inductor DCR current sensing or on-chip bias supply sub-regulator. National’s LM27402, however, is the first universal point-of-load controller to integrate all these advanced features into a single chip - key features required for many types of DC-DC applications.

A wide input voltage range of 3V to 20V allows the LM27402 to interface with all intermediate bus voltages, including 3.3V, 5.0V and 12V rails. Integrated inductor DC resistance current sense eliminates the need for resistive power train elements to detect output current. This increases overall power conversion efficiency and allows accurate continuous current limit sensing. The current sense threshold level is programmable to accommodate a wide range of load current levels using the smallest inductor possible.

Output voltage is adjustable down to 0.6V with a one percent voltage reference providing output voltage set-point accuracy over the full -40 degrees C to 125 degrees C operating temperature range. An integrated bias supply sub-regulator eliminates the external bias voltage supply to simplify PC board layout. Integrated, high-current MOSFET gate drivers with adaptive dead-time control enable ultra-efficient power conversion with load currents as high as 30A. It also supports programmable soft-start, tracking and pre-biased startup.