PMICs optimize power in advanced driver assistance systems

By Warren Miller, contributing writer

Advanced driver assistance systems (ADAS) are seemingly ubiquitous in newer-model automobiles. ADAS functions do everything from engaging the brakes when a collision is imminent to regulating the speed at which the cruise control is set to optimizing the distance between your vehicle and the car in front of you. Applications include collision avoidance, GPS/navigation, adaptive cruise control, lane centering, lane-departure warning, and back-up/surround video. With that in mind, Maxim Integrated Products, Inc. has recently released a new series of power management integrated circuits (PMICs) specifically designed for ADAS power optimization .

Managing DC power in the harsh operational conditions commonly found in automotive environments can be challenging for designers. Package size, electrical protection, and operational efficiency all need to be optimized to ensure high performance. The new Maxim PMIC series includes an array of devices that address the varying needs of ADAS designers. These include the following devices:

• The MAX20019 dual-synchronous step-down converter claims to be the smallest 3.2-MHz dual step-down power supply in a 2 × 3-mm package size.
• The MAX20087 quad-camera power protector monitors as many as four 600-mA coax channels and can identify faults from individual cameras while an I² C interface reports on voltage fault conditions.
• The MAX20075 and MAX20076 synchronous step-down converters boast a 91% high-peak efficiency rate while featuring the lowest quiescent current on the market, according to Maxim.
• The MAX200014 triple-output converter provides a 2.2-MHz switching frequency as well as two synchronous step-down converters and a single synchronous boost converter, allowing for more compact and cost-effective designs compared to its nearest competitors, said Maxim.

(Each product link above provides access to datasheets and ordering information.)

As seen in the graphic below, ADAS uses multiple cameras to help drivers see and react to changes in the environment. You can bet that the number of cameras used in ADAS is going to increase as more applications are found that improve safety.

The MAX20087, by delivering power over coax to up to four cameras, is well-positioned for increased camera use in ADAS. According to the datasheet, the device can deliver up to 600-mA load current to each output channel. Each output is individually protected from short-to-battery, short-to-ground, and overcurrent conditions. The device provides a convenient I² C interface to read system diagnostic status. An on-board ADC enables reading of the current through each switch. The ASIL B- and ASIL D-compliant versions include support for reading an additional seven diagnostic measurements through the ADC, ensuring high-fault coverage.

Applications for Maxim PMICs in ADAS systems. Image source: Maxim.

“Designers must meet demanding requirements along with difficult constraints, which standard catalog parts cannot do effectively,” according to Warren Tsai, director of business management for the Automotive Business Unit at Maxim Integrated. “With this array of carefully tailored, application-specific ICs, Maxim is addressing the complex and unique needs of ADAS designers.”