User Manual

MAX4881–MAX4884
Overcurrent Flag Output ( FLAGI )
The MAX4881–MAX4884 have an overcurrent-fault flag
output (FLAGI) to indicate a current fault condition.
FLAGI asserts low to indicate a fault when the current
reaches the current limit for longer than the 50ms blank-
ing time. Toggle IN or CB or EN to release FLAGI latched
condition. FLAGI does not assert if the current-limit fault
occurs for less than the blanking time (Figure 5).
FLAGI is disabled when EN goes high. When CB is low,
the switch opens, but FLAGI is not active.
FLAGI is an open-drain active-low output. Connect a
pullup resistor from FLAGI to the logic I/O voltage of the
host system, or to any voltage source up to 6V.
Overvoltage Protection Controllers with
Current Limit in TDFN
8 _______________________________________________________________________________________
LOAD
CURRENT
SWITCH
STATUS
OFF
CURRENT
LIMIT
ON
FLAGI
LOAD
CURRENT
SWITCH
STATUS
t
BLANK
t
BLANK
t
BLANK
t
BLANK
CURRENT
LIMIT
ON
(b) MAX4883C/MAX4884C
(a) MAX4881/MAX4882/MAX4883B/MAX4884B
FLAGI
Figure 5. Current-Limit Fault Timing
LOAD
CURRENT
SWITCH
STATUS
t
BLANK
t
BLANK
OFF
ON
EN
STATUS
(a)
FLAGI
PIN STATUS
LOAD
CURRENT
SWITCH
STATUS
t
BLANK
t
BLANK
OFF
ON
(b)
FLAGI
CB
STATUS
(c)
UVLO
LOAD
CURRENT
SWITCH
STATUS
OFF
ON
FLAGI
t
BLANK
t
BLANK
STATUS
IN
STATUS
STATUS
Figure 6. Latch-Off Fault Blanking (MAX4881/MAX4882/
MAX4883B/MAX4884B