ROHM develops automotive primary LDOs

ROHM’s primary LDO regulators models are: BD9xxM5-C (BD933M5EFJ-C/BD950M5EFJ-C/BD900M5EFJ-C/BD933M5WEFJ-C/BD950M5WEFJ-C/BD900M5WEFJ-C). These devices are suitable for supplying power to automotive electronic components such as ECUs that operate from vehicle batteries.

In recent years, the number of onboard power supply systems and functions continues has continued to grow as electrification in the automotive industry progresses. This increases the demand for primary LDOs that can convert the battery voltage directly to MCUs and other components used in ECUs. However, the energy supplied by the vehicle’s lead-acid battery is often subject to sudden voltage fluctuations, which primary LDOs provide with excellent line-transient response in these conditions.

At the same time, ECUs and other downstream devices often experience load current variations during operation that also demand excellent load-transient response characteristics. A high frequency response is essential for fast output voltage recovery, but it has been difficult to provide sufficient phase margin at the same time to ensure stable operation. In response, ROHM developed a novel solution that addresses these challenges.

The BD9xxM5-C incorporates original QuiCur high-speed load response technology that delivers excellent response characteristics to load current fluctuations. For example, the LDO can maintain output to within 100mV of set voltage even as the load changes between 0 and 500mA in 1µs (Rise time/Fall time). Furthermore, low 9.5µA (typ.) current consumption contributes to lower power consumption in automotive applications. These new products will be available in four packages, ranging from the compact HTSOP-J8 to the high heat dissipation TO252 (TO252-3/TO252-5) and HRP5 types. This allows users to select the most suitable package for each use case.

Going forward, ROHM will continue to improve reliability while reducing power consumption in automotive applications by developing products utilising its strengths in analog and other technologies.

Product lineup

The new BD9xxM5-C meets the basic requirements for automotive products, including 150°C operation and qualification under the AEC-Q100 automotive reliability standard. A wide range of packages will be available to select from depending on the application environment, all featuring excellent response performance and low current consumption using proprietary QuiCur technology.

The lineup will be expanded to comprise a total of 18 models, (including the TO252-3, TO252-5, and HRP5 packages) by FY2024.