Automotive multi-regulators for smaller, cheaper car-infotainment systems

December 03, 2015 // By Graham Prophet
A series of highly integrated automotive-grade power-management devices from STMicroelectronics incorporates multiple voltage regulators on a single die, allowing manufacturers of car-infotainment systems to reduce the cost and size of their products.

The first member of the new series, the L5963, integrates two switching regulators for step-down DC-DC conversion, a linear low-dropout regulator, and a high-side driver. The L5963 is made using ST's state-of-the-art BCD8s Automotive process technology with Deep Trench Isolation (DTI). BCD (Bipolar-CMOS-DMOS) is a technology pioneered by ST that allows low-voltage and high-voltage devices to be integrated on the same chip. This means that all of the three integrated voltage regulators can be directly connected to the vehicle battery without any intermediate circuitry, while the DTI technology increases the isolation between internal blocks and reduces interferences among them.

Features of the L5963 include:

Compact solution with three voltage regulators in one small (PSSO36) package;

Maximum flexibility - all regulators can be directly connected to the car battery, with their output voltages determined by simple resistor-resistor external components, while each regulator can be independently enabled or disabled via hardware pins;

High switching frequency up to 2 MHz, minimising the size of external components;

High current capability, up to 3A for each DC-DC regulator, meeting the needs of demanding automotive applications;

Low power dissipation, with a high efficiency of more than 90% at 250 kHz;

Extremely low quiescent current (25 µA typ.) in standby mode, essential for automotive applications when subsystems are always connected to the vehicle battery;

500 mA integrated high-side driver for protected connection of sub-systems to the vehicle battery;

180° phase shift between the DC-DC regulators minimises EMI emissions;

Automotive-qualified (AEC Q100) for use in any car electronic systems.

The high level of integration and the BCD technology eliminate the need to use pre-regulators between the battery and the voltage regulators and allow designers to reduce cost and PCB area by using a single device instead of multiple voltage regulators.

L5963 costs $2.40 (1000). Two PSSO36 package options are offered - slug down for low-power applications and slug up for higher-power applications where a heat-sink is needed.