Allegro MicroSystems, Inc. (“Allegro”), today announced two new full-bridge gate drivers for automotive and industrial applications. Available with direct control (A89505) and pulse-width modulation (A89506) options, these devices up-integrate critical features to make system design easier, replacing mechanical relays with solid-state drivers to improve performance and reliability. With built-in capabilities including flexible interface logic, EMI mitigation with programmable gate drive, motor current feedback and multiple diagnostic features, these devices require very few external components and are available in a 4×4 mm QFN package, 36% smaller than comparable 5×5 mm devices.
The A89505 and A89506 are ideal for vehicle applications such as window and door actuators, EV charger locks, electronic parking brakes, and folding mirrors. Their solid-state design also makes them ideal for battery-powered applications that incorporate brushed DC motors such as building automation and robotics, improving reliability and battery life while facilitating smaller design footprints.
Both drivers include built-in current sensing capabilities, eliminating the need for external current sense resistors and reducing external component requirements to as few as seven. Integrated diagnostics further obviate the need for additional microprocessor programming and additional circuitry. Designers can fit the functionality they need into smaller system footprints, reducing bills of materials (BOMs) and printed circuit board (PCB) sizes while increasing performance and improving the consumer experience.
The A89505 and A89506 build on Allegro’s decades of motor control expertise. Both are capable of 50V absolute maximum supply voltages and offer higher gate drive voltage at low VBB and better efficiency when running on battery power, allowing designers to specify lower-cost FETs. They even enable lower current draw in standby states to reduce total battery load.
“As cars continue down a path toward full electrification, designers are looking for motor drivers that increase performance and battery life without adding size to system designs. The same goes for people designing for Internet of Things and industrial applications,” says Steve Lutz, Business Line Director for Motor Drivers at Allegro. “In addition to being 36% smaller than other drivers on the market, the A89505 and A89506 include advanced features and capabilities that help designers shrink overall PCB sizes and fit everything into more compact modules. Both drivers are easier to use and implement than relays or discrete systems, and increase overall reliability while reducing power consumption.”
Integrated Features Increase Design Flexibility
The A89505 and A89506 gate drivers help provide better motor control than mechanical relays and reduce the need for external components. A programmable gate drive reduces EMI and transients caused by fast switching, and both drivers can adjust the gate current to better control the slew rate of external MOSFETs.
Both devices include current limit detection flags, which are triggered when the programmable current limit is reached. This feature allows a vehicle electronic control unit (ECU) to detect pinches or stalls, with the ability to overdrive a motor in case of ice or freezing.
