Allegro Micro Introduces New Four-Channel High-Side MOSFET Control/Driver IC
Allegro MicroSystems, Inc. introduced a new four-channel high-side MOSFET control/driver IC to complement their existing automotive MOSFET pre-driver family. Allegro’s A3942 is designed to drive four N-channel MOSFETs in a high-side configuration with gate drive outputs that utilize a current-source topology. By using this topology, it is claimed that the A3942 eliminates the need for bootstrap capacitors.
This new device is said to contain the necessary blocks required to provide an efficient interface between the system controller and various high current loads typically found in automotive engine control systems. Allegro’s A3942 is designed to operate over a very wide voltage range (4.5 to 60V) and over the full automotive temperature range, making it a suitable choice for both 12 and 24V 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. The serial port is also used to output a wide range of diagnostics to the controller via a serial-data-out pin.
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 10µA.
Targeted at the automotive market, Allegro’s new A3942 gate driver is priced at $1.87 in quantities of 1,000 and has a 14-week typical lead-time to market.
