The input thresholds have 3.3 V logic sensitivity over the full range of V_DD voltages; it is equally compatible with 0 to V_DD signals. The inputs of the UCC2742x driver family are designed to withstand 500-mA reverse current without damaging the IC for logic upset. The input stage of each driver should be driven by a signal with a short rise or fall time. This condition is satisfied in typical power supply applications where the input signals are provided by a PWM controller or logic gates with fast transition times (<200 ns). The input stages to the drivers function as a digital gate, and they are not intended for applications where a slow changing input voltage is used to generate a switching output when the logic threshold of the input section is reached. While this may not be harmful to the driver, the output of the driver may switch repeatedly at a high frequency.

Users should not attempt to shape the input signals to the driver in an attempt to slow down (or delay) the signal at the output. If limited rise or fall times to the power device is desired, an external resistance can be added between the output of the driver and the load device which is generally a power MOSFET gate. The external resistor may also help remove power dissipation from the device package, as discussed in the section on Thermal Considerations.

Importantly, input signal of the two channels, INA and INB, which has logic compatible threshold and hysteresis. If not used, INA and INB must be tied to either V_DD or GND; it must not be left floating.