Automotive-grade power modules enable 48V power systems for electric vehicles

Vicor has released three automotive-grade power modules for 48V EV systems, which deliver industry-leading power density, and support automotive OEMs and tier one production in 2025. The 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 2.5kW BCM bus converter which converts 800V from the traction battery to 48V 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 158kW/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 mega amps per second allows the BCM6135 to replace a 25lb 48V battery — by serving as a virtual 48V battery in the xEV vehicle and delivering additional cost and weight savings.

The DCM3735 2.0kW DCM DC-DC converter transforms an unregulated 48V input into a regulated 12V 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 – 16V. The DCM3735 has a power density of 300kW/L making it an attractive choice for architectures bridging a 48V distribution to 12V subsystems in zonal ECU applications.

The PRM3735 is a 2.5kW PRM regulator for 48V power that is 99.2% efficient. Its small footprint and 260kW/L power density frees up packaging space and reduces the overall DC-DC power supply. It is best suited to support regulated 48V 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 12V to 48V Zonal Architecture, these products are highly efficient in converting to and from 48V. 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 800V, 400V 48V and 12V systems.

Vicor power modules are reducing power delivery networks throughout the vehicle in innovative ways:

Active suspension

Power needs of active suspension system are too high to be met with 12V power. Switching to a 48V bus and converting down with the bidirectional BCM6135 is an efficient way to deliver high performance. This application also capitalises 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 48V battery — with the BCM serving as a virtual 48V battery in the xEV vehicle, delivering cost and weight savings. Since the BCM6135 can switch from zero current to full current at 8.0MA/s, it can step down the traction battery’s 800 to 48V and power a load as fast as drawing the power from an auxiliary 48V 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. 

48V zonal architecture adoption

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 12V power supply off the BCM6135 48V output. When used as a part of the 48V zonal architecture, the DCM3735 can be mounted remotely to create a local 12V supply in a vehicle zone, for example on the right-hand side. This application method allows the PDN designer to effectively support 12V loads while achieving up to 90% of the cost and weight savings that come from transitioning to a 48V 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 48V adoption. Whether converting the high voltage traction battery to 48V, delivering point-of-load power from a 48V bus, or enabling legacy 12V sub-systems to live in new 48V zonal architectures, Vicor’s high performance, automotive grade power modules deliver the highest power density while reducing power loss and simplifying designs.