Compact LDO regulators for high-performance ADAS sensors

ROHM has created automotive-grade LDO regulator ICs: the BUxxJA3DG-C series (BU12JA3DG-C, BU15JA3DG-C, BU18JA3DG-C, BU25JA3DG-C, BU30JA3DG-C, BU33JA3DG-C). The devices are intended for automotive applications, including sensors for ADAS, which have become smaller and more powerful.

The new BUxxJA3DG-C series satisfies the basic needs for LDOs employed in the secondary power supplies of automotive systems with the compact size and compatibility with standard output voltages. Despite the small package size (2.9mm × 2.8mm), they support output currents of up to 300mA whilst including an input voltage range from 1.7V to 6V. Such low input supply voltage allows the use of the LDO in 1.8V power supply systems to deliver low output voltages at a higher efficiency. Also, the output voltage noise is lowered to only 55µVrms which is about 40% lower than similar 3.3V low-noise LDO regulators. Its series can provide a quieter power supply and greater miniaturisation and performance in ADAS applications.

The series satisfies basic demands, including a compact size, support for 125C operations, qualification under the AEC-Q100 automotive reliability standard, and output voltages needed for automotive secondary LDO regulators.

Also, output currents up to 300mA are supplied from 1.7V to 6V wide input voltage range in a small form factor. Consequently, the lowest output voltage, BU12JA3DG-C, provides stable operation even at 1.7V input/300mA output, allowing use in 1.8V power supply systems. Furthermore, output noise is decreased by 40% over general products (ex: 55µVrms at the BU33JA3DG-C), lessening the effect on minute electrical signals. This makes them excellent for power supplies in compact, high-performance automotive applications where noise is a concern.

Typical application examples include ADAS, sensors, cameras and radar, and car infotainment systems, including clusters and HUDs.