IR21531 Half-Bridge Driver Infineon Technologies IR21531 Half-Bridge Driver has a shutdown feature designed into the CT pin allowing gate driver outputs to be disabled using low voltage control signals. This half-bridge driver achieves improved noise immunity by lowering peak di/dt of the gate drivers and by increasing undervoltage lockout hysteresis to 1V. The IR21531 half-bridge driver features true micropower startup, tighter initial deadtime control, low-temperature coefficient deadtime, and excellent latch immunity on all inputs and outputs. This half-bridge driver offers Electrostatic Discharge (ESD) protection on all leads, lower di/dt gate driver for better noise immunity, and low side output in phase with RT. The IR21531 half-bridge driver is ideal for use in the primary side and lighting fluorescent ballast.