IR Gate Driver ICs Simplify Design
 Driving a MOSFET or IGBT in the high side position of a half-bridge topology or 3 phase inverter leg offers the additional challenge that the gate voltage is referenced to the source rather than to ground. The source voltage is a floating point at up to the maximum bus voltage, or voltage rating of the MOSFET or IGBT, 600V and up for motor drive, lighting or SMPS applications. IR gate driver uses a patented level shifter technology for high voltage application and offers the only 1200V rating in the industry.
These ICs simplify circuit designs by integrating extensive functionality. They use a low cost bootstrap supply, while opto-coupler-based circuits typically require an auxiliary power supply. IR Gate Driver ICs offer optional single input or dual input programmable deadtime control for low side and high side drivers as well as for 3 phase drivers to provide design flexibility and allows to minimize cross-conduction. Unique 3-phase drivers allow driving a 3 phase inverter using a single IC.
IR Gate Driver ICs enable rugged driver designs
IR Gate Driver ICs are specifically designed with motor drive applications in mind. The newest soft-turn-on limits voltage and current spike and reduce EMI. In addition, they have up to 50V/ns dV/dt immunity and are tolerant to negative voltage transient. The under-voltage lock-out available for most drivers prevents shoot-through currents and device failures during power-up and power-down without any additional circuitry. The output drivers feature a high pulse current buffer stage designed for minimum driver cross-conduction.
Noise immunity is important for the high-side position which has a floating voltage and is susceptible to high noise levels, particularly in motor drive applications. Noise immunity ensures that the MOSFET or IGBT doesn't turn on accidentally. Noise immunity is obtained by using Schmitt-triggered input with pull-down. Additional noise immunity is obtained with separate logic and ground pins in some ICs, such as the 600V ICs in 14-pin packages.
IR Gate Driver ICs enable fast switching speeds
IR Gate Drive ICs have ten times better delay matching performance than opto-coupler-based solutions. Delay matching between the low-side and high-side driver is typically within ± 50ns (and as low as ± 10ns for some specialty products), allowing complete dead-time control for better speed range and torque control in motor drive applications. Fast switching also reduces switching power losses and allows leveraging the full benefits of the fastest IGBTs available on the market today for better torque control over a wider speed range.
Application Notes:
AN-978: HV Floating MOS-Gate Driver ICs
AN-985: Six Output 600V MGDs Simplify 3-Phase Motor Drives
Design Notes:
DN500: Short Circuit Protection for Power Inverters
DN501: Accurate Current Sensing in High Voltage Motor Drives
DN502: Short Circuit Protection for Three-Phase Power Inverters
Design Tips:
DT92-2: High Current Buffer for Control ICs
DT04-4: Using Monolithic High Voltage Gate Drivers
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