Manual

8. To set the slew rate, click the Slew Rate selection on the upper left portion of the screen.
9. Set the power-up delay by clicking Power-Up Delay in the lower left portion of the screen. The power-up
delay is the amount of time it takes for a channel to track up after another channel goes into power-good
mode.
10. Set the Fault Up Timer and the Fault Down Timer. These are the maximum allowable times for a channel
output to ramp from zero volts to the channel input voltage, or from the channel input voltage to zero volts.
Be very careful when setting the fault timers: it is possible to generate an unnecessary fault by using slow
slew rates and fast fault timers. The time for a single voltage to track up from zero volts can be calculated
with the following formula:
For example, with a V
IN
of 3.3V, a Power Good Threshold of 95%, and a Slew Rate of 100V/s, the time
required to ramp-up/-down is 31.35ms. Therefore, the Fault Up Timer and Fault Down Timer must be set
to at least 50ms—the 25ms option would cause FAULT to be asserted. If more than one channel is
ramping-up/-down at the same time, the two voltages will track; it is, therefore, possible for the ramp-up/-
down time period to be longer than the theoretical calculation.
Figure 5. Power-Up and Fault Timings for the MAX6876.
11. Set the Fault Behavior option. In Latch-Off mode, the device shuts off after a fault and waits for ENABLE
to be toggled before trying again. In Auto-Retry mode, the device tries again at the specified interval.
12. The Over Current Timer setting determines how long an overcurrent condition must be present in order to
assert the OC output. Set the Over Current timer to a value that will not cause glitches to prematurely
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