Rainbow Electronics MAX4884 - Manual (Page 8)

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