Allegro MicroSystems Releases 4x4mm 50V Full Bridge Grid Drivers for Automotive and Industrial Applications

     Allegro MicroSystems announced the launch of two new full bridge grid drivers for automotive and industrial applications. These devices have direct control (A89505) and pulse width modulation (A89506) options. They can upintegrate key functions to simplify system design, and replace mechanical relays with solid drivers to improve performance and reliability. With flexible interface logic circuit, programmable gate drive to reduce EMI, motor current feedback, multiple diagnostic features and other built-in functions, these devices only need few external components. They are packaged with 4x4mm QFN, 36% smaller than similar 5x5mm devices

     The A89505 and A89506 are ideal for applications such as window and door actuators, electric vehicle charger locks, electronic parking brakes, and folding mirrors. The solid-state design of these devices also makes them very suitable for battery powered applications including brushless DC motors, such as building automation and robotics, which can improve system reliability and battery life, while helping to achieve a smaller footprint design.

These two drivers both contain built-in current sensing functions, without external current sensing resistors. The number of external components required can be reduced to seven, and the integrated diagnostic functions can also eliminate the need for additional microprocessor programming and other additional circuits. Designers can integrate the required functions into a smaller system space, reduce bill of materials (BOM) and PCB size, while improving performance and improving the consumer experience.

 
     The A89505 and A89506 build on Allegro's decades of motor control expertise. Both products can provide an absolute maximum power supply voltage of 50V, provide higher grid drive voltage at low VBB, and provide higher efficiency when using battery power supply, thus allowing designers to use lower cost FETs. These devices can also reduce the low current consumption in standby mode to reduce the total battery load.

     Steve Lutz, Allegro Motor Drive Business Director, said: "As the automobile continues to develop towards full electrification, designers are looking for motor drives that can improve system performance and battery life without increasing the design size of the system, as are designers of the Internet of Things and industrial applications. In addition to being 36% smaller than other drives on the market, A89505 and A89506 also integrate more advanced features and functions, which can help designers reduce the overall PCB size, And can incorporate everything needed into a more compact module. Both drivers are easier to use and implement than relays or discrete systems, reducing power consumption and improving overall reliability. "

     Compared with mechanical relays, A89505 and A89506 grid drivers can provide better motor control and reduce the number of external components required. The programmable gate driver can reduce EMI and transient caused by fast switching, and both drivers can adjust the gate current to better control the slew rate of external MOSFETs.

     Both A89505 and A89506 gate drivers contain current limit detection flags that are triggered when programmable current limits are reached. This function allows the vehicle electronic control unit (ECU) to detect emergencies (pinches) or stops (stalls), and can overspeed drive the motor in case of icing or freezing.