Rainbow Electronics MAX5970 - Manual (Page 26)

0V to 16V, Dual Hot-Swap Controller with 10-Bit
Current and Voltage Monitor and 4 LED Drivers
MAX5970
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If PG_ is asserted and the voltage is outside the warning
limits, the ALERT output is asserted low. Depending on
the status of the prot[] bits in register status1[7:6], the
MAX5970 can also deassert the PG_ output or turn off
the external MOSFET when the voltage is outside the crit-
ical limits (see Figure 3). Table 29 shows the behavior for
the three possible states of the PROT input. Note that the
PROT input does not affect the MAX5970 response to the
UV or OV warning digital comparators; it only determines the system response to the critical digital comparators
(see Tables 4a, 4b, and 29).
In a typical application, the UV1 and OV1 thresholds
would be set closer to the nominal output voltage, and
the UV2 and OV2 thresholds would be set further from
nominal. This provides a progressive response to a volt-
age excursion. However, the thresholds can be config-
ured in any arrangement or combination as desired to
suit a given application.
Table 29. PROT Input and prot[] Bits
Figure 3. Graphical Representation of Typical UV and OV Thresholds Configuration
OV2 CRITICAL THRESHOLD
UV2 CRITICAL THRESHOLD
UV1 WARNING THRESHOLD
OV1 WARNING THRESHOLD
NORMAL RANGE
V MON_
PROT INPUT
STATE
prot[1] prot[0]
UV/OV WARNING
ACTION
UV/OV CRITICAL ACTION
Low 0 0 Assert ALERT Assert ALERT, clear PG_, shutdown channel(s)
High 0 1 Assert ALERT Assert ALERT ,clear PG_
Unconnected 1 0 Assert ALERT Assert ALERT