Three-phase MOSFET driver IC replaces relays in autos

Article By : Allegro

Allegro’s A6862 N-Channel power driver controls the in-phase isolation MOSFETs in automotives.

Allegro has launched an N-Channel power MOSFET driver capable of isolating a three-phase load by controlling the in-phase isolation MOSFETs.

Allegro’s A6862 motor driver IC is intended for automotive systems that must meet Automotive Safety Integrity Level requirements.

[Allegro A6862 motor driver IC fig1 (cr)]
Figure 1: The Allegro A6862 is designed for EPS systems, electric braking and three-phase relay driver applications, and supplied with detailed safety documentation.

In safety critical applications, motor isolation is an essential requirement that is currently addressed with discrete circuitry or relays in most competitive solutions. The A6862 three-phase isolation driver is intended to replace a relay driven motor disconnect in automotive safety critical systems. It also provides the drive for reverse battery protection and battery isolation.

[Allegro A6862 motor driver IC fig2 (cr)]
Figure 2: A6862 MOSFET driver’s functional block diagram.

The A6862 features three independent floating gate drive outputs to maintain the power MOSFETs in the on- or off- states, over the full supply range in the presence of high phase-voltage slew rates. This generation offers the addition of a single input control, two independent activation inputs to put the A6862 into a low power sleep mode, and added gate to source protection to further assist end users to achieve critical system safety goals.

[Allegro A6862 motor driver IC fig3 (cr)]
Figure 3: Diagram of A6862 MOSFET driver’s typical application.

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