Infineon IR21814SPBF: A High- and Low-Side Driver IC for High-Performance Power Conversion Systems

The evolution of modern power electronics is heavily dependent on the critical components that drive their core switching elements. At the heart of many high-performance systems, from motor drives and solar inverters to industrial SMPS, lies the gate driver IC. The Infineon IR21814SPBF stands out as a pivotal component, engineered to deliver robust, efficient, and reliable control for both high-side and low-side N-channel MOSFETs and IGBTs in half-bridge configurations.

This driver IC integrates a floating channel designed for bootstrap operation, significantly simplifying the high-side drive circuitry by eliminating the need for an isolated auxiliary power supply. This architecture allows the high-side section to operate effectively at voltages far exceeding the IC's supply voltage (VCC). With a high voltage range of up to 600V, the IR21814SPBF is well-suited for demanding applications operating from standard three-phase mains voltages.

Performance is further enhanced by its sophisticated level-shifting technology. The IC translates the low-voltage input logic signals from a microcontroller (MCU) or DSP into the high-voltage, high-current pulses required to swiftly switch the power transistors. This is achieved with typical propagation delays of just 150ns, ensuring precise timing between the high-side and low-side channels. Such speed is crucial for maintaining high efficiency, as it minimizes dead time and reduces switching losses in the power devices.

Robustness and protection are fundamental to the IR21814SPBF's design. It features integrated undervoltage lockout (UVLO) for both the high-side and low-side drivers. This safety mechanism shuts down the outputs if the supply voltage drops below a specified threshold, preventing the power switches from operating in a linear region, which could lead to catastrophic failure due to excessive heat. The driver's output stages are capable of sourcing and sinking high peak currents of up to 2.0A and 2.8A, respectively. This strong drive capability ensures rapid turn-on and turn-off of large power MOSFETs or IGBTs, mitigating switching losses and improving overall system thermal performance.

The matched propagation delays between the two channels help in generating well-controlled dead time, which is essential to prevent shoot-through currents—a damaging condition where both high-side and low-side switches conduct simultaneously. Furthermore, the IC is available in a compact yet thermally efficient PDIP-14 package, making it suitable for a wide range of board layouts.

ICGOODFIND: The Infineon IR21814SPBF is an industry-proven, high-voltage gate driver that offers a compelling blend of integration, performance, and protection. It serves as a critical enabler for designers building efficient, compact, and reliable high-performance power conversion systems, effectively bridging the gap between low-power control logic and high-power switching stages.

Keywords: Gate Driver IC, Half-Bridge Driver, High-Voltage Operation, Bootstrap Circuitry, Switching Losses.