600 V BLDC MOSFET gate driver IC for EVs and HEVs

Allegro’s A4900 provides six gate drives capable of driving a wide range of N-channel IGBT or power MOSFET switches. The gate drives are configured as three high-voltage high-side drives and three low-side drives. The high-side drives are isolated up to 600 V to allow operation with high bridge (motor) supply voltages. Highside drives use a bootstrap capacitor to provide greater than the supply gate drive voltage needed for N-channel FET’s. Each FET can be controlled with a TTL logic level input compatible with 3.3 V or 5 V logic systems. 

A single supply input provides the gate drive supply and the bootstrap capacitor charge source. An internal regulator from the single supply provides the lower internal voltage for the logic circuit. The A4900 provides internal monitors to ensure that the gate-source voltage of both high-side and low-side external FET above 9 V when active.

The control inputs to the A4900 provide a very flexible solution for many motor control applications. Each driver can be driven with an independent PWM signal allowing implementation of all motor excitation methods including trapezoidal and sinusoidal drive. Integrated diagnostics provide indication of under voltage, over temperature and power bridge faults that can be configured to protect the power switches under most short circuit conditions. Detailed diagnostics are available as a serial data word.

The A4900KLQTR-T is supplied in a 44 lead QSOP (suffix ‘LQ’) package.

Key features:

• High voltage 3-phase gate drive,
• Floating high-side gate drive to 550 VDC supply,
• Tolerant to high voltage slew rates,
• Cross-conduction protection with fixed dead time,
• 15 V gate drive supply voltage,
• TTL compatible logic inputs,
• Undervoltage detection,
• Overcurrent detection with integrated fault blanking,
• Overtemperature shutdown,
• Matched propagation delays,
• Detailed fault reporting.