IRS23365DMPBF_15 Datasheet, PDF (22/37 Pages) International Rectifier – Gate drive supplies up to 20 V per channel

IRS23365DM
Figure 16: Typical input filter
Figure 17: Advanced input filter
Short-Pulse / Noise Rejection
This device’s input filter provides protection against short-pulses (e.g., noise) on the input lines. If the duration of the input
signal is less than tFIL,IN, the output will not change states. Example 1 of Figure 18 shows the input and output in the low state
with positive noise spikes of durations less than tFIL,IN; the output does not change states. Example 2 of Figure 18 shows the
input and output in the high state with negative noise spikes of durations less than tFIL,IN; the output does not change states.
Figure 18: Noise rejecting input filters
Figures 19 and 20 present lab data that illustrates the characteristics of the input filters while receiving ON and OFF pulses.
The input filter characteristic is shown in Figure 19; the left side illustrates the narrow pulse ON (short positive pulse)
characteristic while the left shows the narrow pulse OFF (short negative pulse) characteristic. The x-axis of Figure 19 shows
the duration of PWIN, while the y-axis shows the resulting PWOUT duration. It can be seen that for a PWIN duration less than
tFIL,IN, that the resulting PWOUT duration is zero (e.g., the filter rejects the input signal/noise). We also see that once the PWIN
duration exceed tFIL,IN, that the PWOUT durations mimic the PWIN durations very well over this interval with the symmetry
improving as the duration increases. To ensure proper operation of the HVIC, it is suggested that the input pulse width for the
high-side inputs be ≥ 500 ns.
The difference between the PWOUT and PWIN signals of both the narrow ON and narrow OFF cases is shown in Figure 20; the
careful reader will note the scale of the y-axis. The x-axis of Figure 20 shows the duration of PWIN, while the y-axis shows the
resulting PWOUT–PWIN duration. This data illustrates the performance and near symmetry of this input filter.
22 www.irf.com © 2012 International Rectifier
3 December, 2012