Automotive primary LDO achieve industry-leading load response characteristics

ROHM has developed 45V rated 500mA output primary LDO regulators, BD9xxM5-C (BD933M5EFJ-C/BD950M5EFJ-C/BD900M5EFJ-C/BD933M5WEFJ-C/BD950M5WEFJ-C/BD900M5WEFJ-C). These devices are suited for supplying power to automotive electronic components, such as ECUs, which operate from vehicle batteries.

In recent years, the number of onboard power supply systems and functions 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 supply with excellent line-transient response in these conditions.

At the same time, ECUs and other downstream devices often experience load current variations throughout operation that also demand excellent load-transient response characteristics. A high-frequency response is crucial for fast output voltage recovery, but providing sufficient phase margin simultaneously has been challenging to ensure stable operation. In response, the company developed a novel solution that addresses these challenges.

The BD9xxM5-C includes original QuiCur high-speed load response technology, delivering 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 adds to lower power consumption in automotive applications. These new products will be obtainable in four packages, ranging from the compact HTSOP-J8 to the high heat dissipation TO252 (TO252-3/TO252-5) and HRP5 types. This permits users to select the most suitable package for each use case.

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

By FY2024, the lineup will be expanded to 18 models (including the TO252-3, TO252-5, and HRP5 packages).

The devices are suitable for a wide range of automotive applications, such as ECUs that operate on vehicle primary power supply systems, powertrains, body systems, and Infotainment.