LDOs work up to 42V for direct connection to automotive batteries

Rohm has announced a series of 50mA low drop-out linear regulators designed to be connected directly to the vehicle battery circuits without an intermediate regulator.

Rohm BD7xxL05G-C automotive primary LDOs

Called BD7xxL05G-C, their inputs operate up to 42V and can survive 45V.

The parts are:
BD725L05G-C (2.5Vout, 3.5Vin min),
BD730L05G-C (3.0Vout, 3.5Vin min),
BD733L05G-C (3.3Vout, 3.8Vin min) and
BD750L05G-C (5.0Vout, 5.6Vin min).
Output voltages are ±2% accurate.


They are “optimised for redundant power supplies that are increasingly being used in automotive applications to improve the reliability of vehicle power systems”, said Rohm. “Redundant power supplies can continue to operate core functions – sub-MCUs – even in the event of a main system malfunction.”


Packaged in a 2.9 x 2.8 x 1.25mm SSOP5 (two pins are not connected), they typically consume only 6μA.

To reduce the need for large output capacitors, the internal circuit is optimised for low over-shoot when subjected to input steps (110mV overshoot with 4.9 > 16V step at 1V/μs, 5V version with Cout=1μF and 30mA load, 25°C). The capacitive load on the output can vary across 500nF to 1,000μF.

“Also, high resistance to disturbance noise is achieved, suppressing output voltage fluctuations to less than 50mV, or <±1%, over the entire frequency band under ISO 11452-2 antenna irradiation testing,” according to the company.

Operation in over -40 to +125°C (+150°C survival), and all parts are AEC-Q100 automotive grade.

Applications are foreseen in braking systems, electric power steering, automated driving control units, driving recorders, body control modules, real-time clocks and door handle modules.

The BD7xxL05G-C series data sheet can be found here


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