Three-phase isolator MOSFET driver IC is designed to replace mechanical relays
Allegro MicroSystems, LLC (Worcester, MA) introduced a new N-channel power MOSFET driver capable of isolating a three phase load by controlling the in-phase isolation MOSFETS. Allegro’s A6861 motor driver IC is intended for automotive systems that must meet Automotive Safety Integrity Level (ASIL) requirements. The A6861 has three independent floating gate drive outputs to maintain the power MOSFETs in the on state, or the off state, over the full supply range in the presence of high phase-voltage slew rates. With the addition of a few external components it can also isolate the load when high load currents are present. An integrated charge pump regulator provides the above battery supply voltage necessary to maintain the power MOSFETs in the on state continuously when the phase voltage is equal to the battery voltage. The charge pump will maintain sufficient gate drive (>7.5 V) for battery voltages down to 4.5 V with 100 kΩ gate-source resistors. The three gate drives can be independently controlled by a logic level control input. Key applications include:
- EPS (Electronic Power Steering) systems.
- Electric braking.
- Three-phase relay drivers.
For more information, visit www.allegromicro.com