A4940K: Automotive Full Bridge MOSFET Driver

The A4940 is a full-bridge controller for use with external N-channel power MOSFETs and is specifically designed for automotive applications with high-power inductive loads such as brush DC motors.

A unique charge pump regulator provides full (>10 V) gate drive for battery voltages down to 7 V and allows the A4940 to operate with a reduced gate drive, down to 5.5 V.

A bootstrap capacitor is used to provide the above battery supply voltage required for N-channel MOSFETs. A unique bootstrap charge management system ensures that the bootstrap capacitor is always sufficiently charged to supply the high-side gate drive circuit.

Each of the power MOSFETs is controlled independently but all are protected from shoot-through by dead time that is userconfigured by an external resistor.

Integrated diagnostics provide indication of undervoltage and overtemperature faults.

The A4940 is supplied in a 24-pin TSSOP power package with an exposed pad for enhanced thermal dissipation (package type LP). It is lead (Pb) free, with 100% matte tin leadframe plating (suffix –T).

These parts are in production but have been determined to be NOT FOR NEW DESIGN. This classification indicates that sale of this device is currently restricted to existing customer applications. The device should not be purchased for new design applications because obsolescence in the near future is probable. Samples are no longer available. Date of status change: December 5, 2018

Recommended Substitutions: Contact Allegro Sales.

• High current gate drive for N-channel MOSFET full bridge
• Independent control of each MOSFET
• Charge pump for low supply voltage operation
• Cross-conduction protection with adjustable dead time
• 5.5 to 50 V supply voltage range
• Diagnostics output
• Low current sleep mode