Four-channel high-side control/driver IC for automotive systems

The A3942, which complements Allegro’s existing automotive MOSFET pre-driver family, is designed to drive four N-channel MOSFETs in a high-side configuration with gate drive outputs that use a current-source topology, thereby eliminating the need for bootstrap capacitors.

The new device offers a high degree of flexibility for automotive engine control systems. It is designed to operate over a very wide voltage range (4.5 V to 60 V) and over the full automotive temperature range, making it an ideal choice for both 12 V and 24 V engine control systems.

The four outputs can be controlled with either four parallel input lines or through an integrated serial peripheral interface (SPI). The serial interface greatly increases the flexibility of the IC by allowing software control of channel-specific blanking times for short-to-ground detection.

Extensive fault protection and diagnostic capabilities include use of the serial port to output a wide range of diagnostic signals to the controller via a serial data output pin. The A3942 provides full protection against open-load, short-to-ground and short-to-battery events, and reports all diagnostics back to the controller. Short-circuit fault thresholds can be adjusted on a ‘per channel’ basis with inexpensive external resistors.

Multiple A3942 devices can share an SPI interface by either connecting them in parallel or in a ‘daisy chained’ series using the chip select pin to address the appropriate IC. A ‘sleep’ mode is provided to reduce the quiescent current draw to less than 10 µA.

The A3942 is supplied in the automotive 38L TSSOP package.

A data sheet of this product can be viewed and downloaded from: http://www.allegromicro.com/en/Products/Part_Numbers/3942/3942.pdf