IR21531STRPBF is a self-oscillating half-bridge gate driver. It incorporates a high-voltage half-bridge gate driver with a front-end oscillator similar to the industry standard CMOS 555 timer. The IR21531 provides more functionality and is easier to use than the previous IC. A shutdown feature has been designed into the CT pin so that both gate driver outputs can be disabled using a low-voltage control signal. In addition, the gate driver output pulse width is the same once the rising undervoltage lockout threshold on VCC has been reached, resulting in a more stable profile of frequency vs time at startup. Noise immunity has been improved significantly, both by lowering the peak di/dt of the gate driver, and by increasing the undervoltage lockout hysteresis to 1V. Finally, special attention has been paid to maximizing the latch immunity of the device, and providing comprehensive ESD protection on all pins.