The UCC44273 features very low quiescent I_DD currents. The typical operating-supply current in Undervoltage-Lockout (UVLO) state and fully-on state (under static and switching conditions) are summarized in Figure 6-3, Figure 6-3 and Figure 6-4. The I_DD current when the device is fully on and outputs are in a static state (DC high or DC low, refer Figure 6-2) represents lowest quiescent I_DD current when all the internal logic circuits of the device are fully operational. The total supply current is the sum of the quiescent I_DD current, the average I_OUT current due to switching. Knowing the operating frequency (f_SW) and the MOSFET gate (Q_G) charge at the drive voltage being used, the average I_OUT current can be calculated as product of Q_G and f_SW.

A complete characterization of the I_DD current as a function of switching frequency at different V_DD bias voltages under 1.8-nF switching load is provided in Figure 6-12. The strikingly-linear variation and close correlation with theoretical value of average I_OUT indicates negligible shoot-through inside the gate-driver device attesting to the high-speed characteristics of I_OUT.