ROHM’s New Compact 300mA Automotive-Grade LDO Regulators for High Performance ADAS Sensors


ROHM developed automotive-grade LDO regulator ICs: the BUxxJA3DG-C series (BU12JA3DG-C, BU15JA3DG-C, BU18JA3DG-C, BU25JA3DG-C, BU30JA3DG-C, BU33JA3DG-C). The devices are designed for automotive applications such as sensors for ADAS (Advanced Driver Assistance Systems) which have become smaller and more powerful.

In recent years, safety requirements in the automotive sector have increased as technological innovations in accident prevention and autonomous driving continue to progress. In line with this, sensors and cameras installed in ADAS are becoming increasingly sophisticated, necessitating power supply ICs that deliver larger currents in a smaller package size.

In the past years, ROHM has already offered compact, energy-saving solutions utilizing an extensive lineup of DC-DC converters and LDO regulators for a wide range of automotive applications, including ADAS and ECUs.

The new BUxxJA3DG-C series meets the basic requirements for LDOs used in the secondary power supplies of automotive systems (i.e. compact size, compatibility with standard output voltages). On top of that, despite their small package size (2.9mm × 2.8mm), they support output currents of up to 300mA while covering an input voltage range from 1.7V to 6V. Such low input supply voltage enables the use of the LDO in 1.8V power supply systems to provide low output voltages at a higher efficiency. Furthermore, the output voltage noise is reduced to just 55μVrms which is about 40% lower than similar 3.3V low-noise LDO regulators. As a result, its series is able to provide a more quiet power supply along with greater miniaturization and performance in ADAS applications.

Going forward, ROHM will continue to support the evolution of vehicles by developing power supply ICs that contribute to greater power savings and miniaturization in automotive applications.

Overview of Secondary LDO Regulators
ROHM’s Automotive Secondary LDO Regulator Series Lineup

New Product Lineup

The BUxxJA3DG-C series meets basic requirements, including a compact size, support for 125°C operations, qualification under the AEC-Q100 automotive reliability standard, and output voltages required for automotive secondary LDO regulators.

At the same time, output currents up to 300mA are provided from 1.7V to 6.0V wide input voltage range in a small form factor. Hence, the lowest output voltage, BU12JA3DG-C ensures stable operation even at 1.7V input/300mA output, enabling use in 1.8V power supply systems. In addition, output noise is reduced by 40% over general products (ex: 55μVrms at the BU33JA3DG-C), reducing the effect on minute electrical signals. This is making them ideal for power supplies in compact, high-performance automotive applications where noise is a concern.

Secondary LDO Regulator Output Noise Comparison
Part No. Data
Difference (Max.)
[mV] (lo=300mA)
Tj [℃]
BU12JA3DG-C PDF 1.7 to 6.0 1.2 ±2 300 500 37 1 to 47 -40 to +150 SSOP5
BU15JA3DG-C 1.9 to 6.0 1.5 365
BU18JA3DG-C 2.2 to 6.0 1.8 330
BU25JA3DG-C 2.8 to 6.0 2.5 240
BU30JA3DG-C 3.3 to 6.0 3.0 220
BU33JA3DG-C 3.6 to 6.0 3.3 200

Application Examples

◇ ADAS, sensors, cameras and radar
◇ Car infotainment systems including clusters and head-up displays (HUDs)
Enables use in a wide range of applications and fields, especially secondary power supplies for noise-sensitive automotive applications.

Pricing: $1.00/unit (samples, excluding tax)
Availability: Now (in mass production)

Online Sales Information

Sales Launch Date: September 2022
Online Distributors: Digi-key, Mouser, and Farnell
Part Nos:

Online Distributors


LDO Regulator (Low Drop Out/Low Saturation Regulator)
A type of power supply IC that converts between two different DC voltage levels. Falls under the category of linear regulator (where the input/output voltages operate linearly) characterized by a small input-output voltage difference. Compared to DC-DC converter ICs (switching regulators), LDOs feature a simpler circuit configuration and lower noise.
In an automotive power supply, the side in charge of 1st stage conversion from a power source such as a battery is called the primary. Similarly, the side responsible for 2nd stage conversion is called the secondary. Power supply ICs for primary applications are required to support high input voltages, while secondary power supply ICs operate in the low input/output regime.


300mA products are now available in addition to the popular 200mA low noise series
Compact 300mA Output Secondary CMOS LDO Regulators (PDF:647KB)