High Speed 650V Half-Bridge Driver for GaN Power Switches

The NCP51820 high−speed, gate driver from ON Semiconductor is designed to meet the stringent requirements of driving enhancement mode (e−mode), high electron mobility transistor (HEMT) and gate injection transistor (GIT), GaN power switches in off−line, half−bridge power topologies.

The NCP51820 offers short and matched propagation delays with advanced level shift technology providing −3.5V to +650V (typical) common mode voltage range for the high−side drive and −3.5V to +3.5V common mode voltage range for the low−side drive. In addition, the device provides stable dV/dt operation rated up to 200V/ns for both driver output stages in high speed switching applications.

Typical Applications:

• Driving GaN Power Transistors used in Full or Half−Bridge, LLC, Active Clamp Flyback or Forward, Totem Pole PFC and Synchronous Rectifier Topologies
• Industrial Inverters and Motor Drives
• AC-DC Converters

To fully protect the gate of the GaN power transistor against excessive voltage stress, both drive stages employ a dedicated voltage regulator to accurately maintain the gate−source drive signal amplitude. The circuit actively regulates the driver's bias rails and thus protects against potential gate−source over−voltage under various operating conditions.

The NCP51820 offers important protection functions such as independent under−voltage lockout (UVLO), monitoring VDD bias voltage and VDDH and VDDL driver bias and thermal shutdown based on die junction temperature of the device. Programmable dead−time control can be configured to prevent cross−conduction.

Summary of Features

• 650V, Integrated High−Side and Low−Side Gate Drivers
• UVLO Protections for VDD High and Low−Side Drivers
• Dual TTL Compatible Schmitt Trigger Inputs
• Split Output Allows Independent Turn−ON/Turn−OFF Adjustment
• Source Capability: 1A; Sink Capability: 2A
• Separated HO and LO Driver Output Stages
• 1ns Rise and Fall Times Optimized for GaN Devices
• SW and PGND: Negative Voltage Transient up to 3.5V
• 200V/ns dV/dt Rating for all SW and PGND Referenced Circuitry
• Maximum Propagation Delay of Less Than 50ns
• Matched Propagation Delays to Less Than 5ns
• User Programmable Dead−Time Control
• Thermal Shutdown (TSD)