Power supply ICs for automotive applications

June 14, 2013 // By Graham Prophet
Rohm has announced compact, high efficiency power supplies designed to drive DDR memory, microcontrollers, and other components in car applications. The BD905xx series integrates a phase compensation circuit and feedback resistor, reducing the number of external parts considerably compared with conventional power supply ICs.

With the trend towards improved performance and decreasing model cycles in the automotive industry comes a need for easier-to-use, high efficiency power supply ICs that lighten the design load and minimise mounting area. A primary factor in the number of external components used with power supply ICs is the phase compensation circuit required to maintain a stable output voltage. Normally external capacitors and resistors are used to set the desired characteristics. However, ROHM was able to optimise the phase compensation circuit internally, reducing parts count by 80% and contributing to more compact automotive systems. In addition, phase compensation adjustment, which is a common problem with power supply designs, is no longer required, shortening design time significantly.

ROHM power supply ICs utilise synchronous rectification for high efficiency operation, in combination with Light Load Mode, ensuring superior performance with low current consumption under all load conditions. Packaging is HTSOP-J8 (6.0 x 4.9 mm, t=1.0mm max.), losses are 10% of those of an LDO in a typical configuration, and synchronous rectification, coupled with Light Load Mode, results in over 90% efficiency (max.) under all load conditions for minimal current consumption.

Rohm Semiconductor; www.rohm.com