Integrated Grade 0 BLDC motor driver shrinks 48-V motor-drive systems

Texas Instruments motor driver enables Automotive Safety Integrity Level ASIL D and achieves the industry’s highest gate-drive current.


Texas Instruments introduced a highly integrated Grade 0 brushless DC (BLDC) motor driver for 48-V high-power motor control systems, such as traction inverters and starter generators in mild hybrid electric vehicles (MHEVs). The DRV3255-Q1 can help designers shrink their motor system size by 30% while providing the industry’s highest gate-drive current for increased protection and output power. The new motor driver was designed according to TI’s TÜV SÜD-certified functional safety development process, enabling Automotive Safety Integrity Level (ASIL) D. 

To help decrease greenhouse gas emissions globally, automobile manufacturers are increasing the production of MHEVs, which use 48-V motor-drive systems to help reduce emissions from a vehicle’s internal combustion engine. The TI Functional Safety-Compliant DRV3255-Q1 allows manufacturers to design a motor-drive system to help enable MHEV systems up to ASIL D, supplying as much as 30 kW of motor power which, can improve the response time of a 48-V motor-drive system in heavy vehicles.

Asif Anwar, Director of the Powertrain, Body, Chassis and Safety Service, Strategy Analytics, said: “A 48-V system is a step-change that original equipment manufacturers [OEMs] can implement to meet goals around reducing emissions, while also adding power for advanced driver-assistance system features and managing power-hungry loads, such as the heating, ventilation and air conditioning system. Combining leading-edge performance characteristics with functional safety and Grade 0 translates to real-world, system-level operational benefits that will help OEMs achieve these goals.”

The active short-circuit logic feature gives system designers the flexibility to arrange metal-oxide-semiconductor field-effect transistor (MOSFET) connections based on system needs and helps prevent catastrophic system failures due to overvoltage. The dynamic fault response automatically switches the motor driver to active short-circuit mode in overvoltage conditions, which protects the vehicle’s motor and electrical components from overvoltage stress while optimizing system performance.

Built with functional safety in mind, the DRV3255-Q1 was designed using TI’s certified functional safety hardware development process and includes built-in safety mechanisms and documentation such as failure modes, effects and diagnostic analysis and a functional safety manual. In addition to the safety mechanisms for the device’s internal failure modes, the digital input/output pins withstand up to 75-V absolute maximum ratings to protect the DRV3255-Q1 against an external 12-V power-supply overvoltage.

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