Features
- 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
Description
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).
Functional Block Diagram
