BLDC motor driver shrinks motor-drive systems in MHEVs

Texas Instruments (TI) has released an 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). MHEvs use 48-V motor-drive systems to help reduce emissions from a vehicle’s internal combustion engine as well as add power for advanced driver assistance features and manage power-hungry loads, according to TI.

TI claims the DRV3255-Q1 motor driver is the industry’s first three-phase, 48-V BLDC motor driver to integrate high- and low-side active short-circuit logic, eliminating external transistors and control logic. The DRV3255-Q1 can shrink motor system size by as much as 30%, said TI, while providing the industry’s highest gate-drive current for increased protection and output power.

The integrated active short-circuit logic feature enables system designers to arrange MOSFET connections based on system needs, and helps prevent catastrophic system failures due to overvoltage, said TI, while the integrated dynamic fault response automatically switches the motor driver to active short-circuit mode in overvoltage conditions to protect the motor and electrical components from overvoltage stress.

The motor driver was designed according to TI’s TÜV SÜD-certified functional safety development process. It also includes built-in safety mechanisms and documentation such as failure modes, effects and diagnostic analysis, and a functional safety manual.

The TI Functional Safety-Compliant device helps manufacturers to design a motor-drive system 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, said TI.

TI DRV3255-Q1 motor driver common applications schematic (Image: Texas Instruments)

The DRV3255-Q1 also claims the industry’s highest output power levels to improve 48-V motor-drive system response times, so drivers even in heavy vehicles can accelerate more quickly after stopping. For motors requiring currents as high as 600 A, the DRV3255-Q1 delivers the industry’s highest gate-drive current, which can directly drive up to 1,000-nC gate-charge MOSFETs, said TI.

The Automotive Electronics Council (AEC)-Q100 Grade 0 motor driver also protects 48-V powertrain systems from switching transients as high as 95 V and load-dump conditions over a wide temperature range of -40°C to 150°C, eliminating the need for protection circuitry.

The DRV3255-Q1 is available now from TI in a 64-pin quad flat package with prices starting at $3.99 in quantities of 1,000. Full and custom quantity reels are available now, only on TI.com.

TI recently introduced a wireless battery management system for EVs that complies with ASIL-D requirements. The wireless BMS is the first independently assessed functional safety concept through TÜV SÜD, according to TI.