The A4957 is used with an external N-channel power MOSFETFull-bridge controllerIt is especially designed for applications using high-power inductive loads, such as DC brush motors.
Unique charge pump regulator provides complete (>10 V)Gate driversto handle battery voltages as low as 7 V and allow the A4957 to operate when the gate driver voltage drops to 4.5 V.
The bootstrap capacitor is used to provide the above battery supply voltage required for the N-channel MOSFET. A unique bootstrap charge management system ensures that the bootstrap capacitor is always fully charged to supply the high-side gate driver circuitry.
The user-configurable inductive time of the external resistor independently controls each power MOSFET and protects it from breakdown.
Integrated diagnostics indicate undervoltage and overtemperature faults.
The A4957 is available in a 24-contact 4 mm × 4 mm × 0.75 mm QFN package with exposed pads for enhanced heat dissipation. The packages are Pb-free and feature 100% matte tin plating (suffix –T).
- N-channel MOSFET full-bridge high current gate driver
- Control each MOSFET independently
- Charge pump for operation at low supply voltages
- Cross-conduction protection with adjustable non-inductive time
- The supply voltage range is 4.5 to 50 V
- Diagnostic output
- Low current sleep mode