SLUSDC2C November 2018 – September 2019 UCC20225-Q1 , UCC20225A-Q1
PRODUCTION DATA.
If the DT pin is left open, the dead time duration (tDT) is set to <15-ns. It is not recommended to leave DT pin open for noisy environment. One can program tDT by placing a resistor, RDT, between the DT pin and GND. The appropriate RDT value can be determined from Equation 1, where RDT is in kΩ and tDT in ns:
The steady state voltage at DT pin is around 0.8V, and the DT pin current will be less than 10uA when RDT=100-kΩ. Since the DT pin current is used internally to set the dead time, and this current decreases as RDT increases, it is recommended to parallel a ceramic capacitor, 2.2-nF or above, close to DT pin to achieve better noise immunity and better dead time matching between two channels, especially when the dead time is larger than 300-ns.
The input signal’s falling edge activates the programmed dead time for the output. An output signal's dead time is always set to the driver’s programmed dead time. The driver dead time logic is illustrated in Figure 36: