The input pins of the UCC27624-Q1 gate driver device are based on a TTL compatible input threshold logic that is independent of the VDD supply voltage. With a high threshold of 2 V and a low threshold of 1 V, the logic level thresholds are conveniently driven with PWM control signals derived from 3.3-V and 5-V digital power controller devices. Wider hysteresis (1-V typical) offers enhanced noise immunity compared to traditional TTL logic implementations, where the hysteresis is typically less than 0.5 V. UCC27624-Q1 devices also feature tight control of the input pin threshold voltage levels, which eases system design considerations and ensures stable operation across temperature (refer to Typical Characteristics). The very low input capacitance on these pins reduces loading and increases switching speed.

The UCC27624-Q1 device features an important protection feature that holds the output of a channel low when the respective input pin is in a floating condition. This is achieved through the internal pulldown resistors to ground on both of the input pins (INA, INB), as shown in .

The input pins can handle wide range of slew rate. In most power supply applications, the gate driver is either driven by the output of a digital controller or logic gates. Therefore, in most applications the input signal slew rate is fast and is no concern for the UCC27624 family of devices. The wide hysteresis offered in UCC27624-Q1 alleviates the concern of chattering compared to many other drivers that have very small hysteresis at the input. If limiting the rise or fall times to the power device is the primary goal, then an external gate resistor is highly recommended between the output of the driver and the gate of the switching power device. This external resistor has the additional benefit of reducing part of the gate-charge related power dissipation in the gate driver device package and transferring it into the external resistor itself. In short, some of the power gets dissipated in the gate resistor rather than inside of the gate driver. Additionally, the input pins of UCC27624-Q1 are capable of handling –10 V. This improves the system robustness in noisy (electrical) applications. This also enables the driver to directly connect to the output of a gate drive transformer without the use of rectifying diodes, which saves board space and BOM cost.