8.4.2.2 DT Pin Left Open or Connected to a Programming Resistor between DT and GND Pins

If the DT pin is left open, the dead time duration (t_DT) is set to <15-ns. It is not recommended to leave DT pin open for noisy environment. One can program t_DT by placing a resistor, R_DT, between the DT pin and GND. The appropriate R_DT value can be determined from Equation 1, where R_DT is in kΩ and t_DT in ns:

Equation 1.

The steady state voltage at DT pin is around 0.8V, and the DT pin current will be less than 10uA when R_DT=100-kΩ. Since the DT pin current is used internally to set the dead time, and this current decreases as R_DT 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:

Figure 36. Input and Output Logic Relationship with Dead Time