Power modules enable 48-V power systems for EVs

Aimed at automotive OEMs and tier one production, three automotive-grade power modules for 48-V EV systems have been released by Vicor.

The power modules, designated BCM6135, DCM3735 and PRM3735, use AEC-Q100 certified Vicor-designed ICs and have completed the PPAP process with automotive customers.

The BCM6135 is a 98% efficient 2.5 kW BCM® bus converter which converts 800-V from the traction battery to 48-V to provide a safety extra-low voltage (SELV) power supply for the vehicle. The BCM6135 internally provides the isolation between high voltage and low voltage which creates a large reduction the space required for the DC-DC conversion. The BCM6135’s power density of 158 kW/L allows EV system designers to reduce size of the primary DC-DC converter and reduce vehicle weight. The bidirectional rapid current transient response rate of 8 MA/s allows the BCM6135 to replace a 48-V battery — by serving as a virtual 48-V battery in the xEV vehicle and delivering additional cost and weight savings.

The DCM3735 2.0 kW DCM™ DC-DC converter transforms an unregulated 48-V input into a regulated 12-V output. The DCM3735 has a wide input range that is compatible with a variety of automotive applications because the output can be trimmed within a range of 8- to 16-V. The DCM3735 has a power density of 300 kW/L making it an attractive choice for architectures bridging a 48-V distribution to 12-V subsystems in zonal ECU applications.

The PRM3735 is a 2.5 kW PRM™ regulator for 48-V power that is 99.2% efficient. Its small footprint and 260 kW/L power density frees up packaging space and reduces the overall DC-DC power supply. It is best suited to support regulated 48-V loads that are implemented in new vehicle architectures.

The newly released Vicor modules can be arranged in over 300 configurations, offering extreme flexibility and scalability to support innovation for a variety of vehicle subsystems. Further, as the market shifts from 12-V to 48-V Zonal Architecture, these products are highly efficient in converting to and from 48-V. All three modules can be arrayed easily to increase power supply levels, and they have automatic power sharing for optimum performance in an array. These modules solve complex challenges with 800-V, 400-V 48-V and 12-V systems.

“Vicor has set a new standard for power density in the automotive industry with these scalable and flexible miniature power modules,” said Patrick Wadden, VP of the Vicor Automotive business unit. “Our high-performance converters enable new possibilities for automotive manufacturers to reduce the size and weight of power systems throughout the vehicle.”

“Our power modules make it easy to convert from the primary battery (800-V or 400-V) to 48-V and down to load,” said Wadden. “They are very versatile, and our customers are using the modules in innovative ways that are helping them remove size and weight from their power systems.”

Vicor power modules are reducing power delivery networks throughout the vehicle. Key applications include:

• Active suspension in EVs — Power needs of active suspension system are too high to be met with 12-V power. Switching to a 48-V bus and converting down with the bidirectional BCM6135 is an efficient way to deliver high performance. This application also capitalizes on the BCM6135’s high slew rate as the active suspension is a regenerative power load, which requires immediate current flow reversal to pass regenerated power back to the battery.
• Deleting or reducing the low-voltage battery — The industry-leading slew rate of the BCM6135 presents an opportunity to replace a 48-V battery — with the BCM serving as a virtual 48-V battery in the xEV vehicle, delivering cost and weight savings. Since the BCM6135 can switch from zero current to full current at 8.0 MA/s, it can step down the traction battery’s 800 to 48-V and power a load as fast as drawing the power from an auxiliary 48-V battery. No other DC-DC converter can match this speed and enables customers to reduce vehicle weight by up to 25kg while reducing vehicle costs by up to $100.00.
• 48-V zonal architecture adoption is on every roadmap — The new power modules can be easily configured to make this transition easier. The DCM3735 is used in conjunction with BCM3735 to create a regulated 12-V power supply off the BCM6135 48-V output. When used as a part of the 48-V zonal architecture, the DCM3735 can be mounted remotely to create a local 12-V supply in a vehicle zone, for example on the right-hand side. This application method allows the PDN designer to effectively support 12-V loads while achieving up to 90% of the cost and weight savings that come from transitioning to a 48-V bus.
• Pre-charging prevents current surges and saves weight — Pre-charging is a necessary step of the start-up process. It prevents current surges at battery engagement that will damage the loads (such as pumps and compressors). Currently this is done using high voltage contactors and resistors, which add 1kg and over $50 in cost. The alternative is to use BCM6135 as the main DC-DC converter and one of the low-voltage batteries installed in the vehicle. The BCM6135 can boost the low-voltage battery power up to high voltage and achieve the needed pre-charge, eliminating the legacy pre-charge contactor and power resistor.

The flexibility of the power modules enable a host of automotive applications to be powered. More importantly, they deliver on the promise of 48-V adoption. Whether converting the high voltage traction battery to 48-V, delivering point-of-load power from a 48-V bus, or enabling legacy 12-V sub-systems to live in new 48-V zonal architectures, these high performance, automotive grade power modules deliver the highest power density while reducing power loss and simplifying designs.