Automotive grade 3-phase isolator MOSFET drivers
The A6861 is an N-channel power capable of controlling MOSFETsMOSFET drivers, connected as a three-phase solid state relay in phase-isolated applications. The A6861 is intended for automotive systems that must meet ASIL requirements. Motor isolation is a critical safety requirement in safety-critical applications that is currently addressed by discrete circuits or relays. Allegro A2-SILTM products include specific features that enable proper system design, allowing users to achieve ASIL-D system ratings.
The A6861 has three independent floating gate drive outputs, allowing the power MOSFETs to maintain the on (ON) state beyond the full supply range in the presence of high phase slew rates. An integrated charge pump regulator provides the necessary voltage above the battery supply voltage to keep the power MOSFET running in the on (ON) state when the phase voltage is equal to the battery voltage. The charge pump provides sufficient gate-level drive (>7.5 V) for battery voltages as low as 4.5 V through a 100 kΩ gate resistor.
The three gate-level drives can be controlled independently by using a logic hierarchy control input. In a typical application, the MOSFET will start up within 8 μ seconds and shut down within 1 μ seconds.
The undervoltage monitor checks that the pump supply voltage is high enough to ensure that the MOSFET remains in a safe conductive state.
The A6861 is available in a 16-pin TSSOP (LP) package with an exposed heat shield for enhanced heat dissipation. The packages are Pb-free and the leadframes are 100% matte tin.
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- Three-phase safe disconnect system
- Electronic Power Steering (EPS)
- Electronic brake
- Three-phase solid state relay driver
- 3 floating N-channel MOSFET drivers
- VGS is maintained with a 100 kΩ gate resistor
- Integrated charge pump controller
- 4.5 to 50 V supply voltage operating range
- Each phase has an independent TTL input
- 150°C ambient (165°C solder joint temperature) conditions
- A2-SILTM Products – Devices built for safety-critical systems