August 1, 2017
Allegro MicroSystems, LLC announces two new N-channel power MOSFET driver ICs capable of controlling MOSFETs connected in a half-bridge arrangement. Allegro’s A4926 and A4927 are specifically designed for automotive applications with high-power inductive loads, such as, DC Pumps (Braking, Oil, Water, and Fuel), HVAC (Blower Fan), solenoids, and actuators. These devices are intended for automotive systems that must meet ASIL requirements. In common with other Allegro A2SIL™ products, this device incorporates features to complement proper system design, allowing users to achieve the required ASIL level.
A unique charge pump regulator provides full gate drive for battery voltages down to 5.5 V for most applications. A bootstrap capacitor, with optional bootstrap management, is used to provide the above-battery supply voltage required for N-channel MOSFETs. The half-bridge can be controlled by independent logic-level inputs or through the SPI-compatible serial interface. The external power MOSFETs are protected from shoot-through by a programmable dead time.
Integrated diagnostics provide indication of multiple internal faults, system faults, and power bridge faults, and can be configured to protect the power MOSFETs under most short-circuit conditions. In addition to providing full access to the bridge control, the serial interface is also used to alter programmable settings such as dead time, VDS threshold, gate drive current, and fault blank time. Detailed diagnostic information can be read through the serial interface. In addition, the A4927 includes an integrated low side current amplifier with programmable gain and offset.
The A4926 is supplied in a 20-lead eTSSOP (suffix LP). This package is lead (Pb) free, with 100% matte-tin leadframe plating (suffix –T).
The A4927 is supplied in a 24-lead eTSSOP (suffix LP). This package is lead (Pb) free, with 100% matte-tin leadframe plating (suffix –T).