IMON pin open: In this case, the IMON pin
voltage is internally pulled up to a higher voltage and exceeds the threshold
(VIREF), causing the part to perform a circuit-breaker action
even if there is no significant current flowing through the device.
IMON pin shorted to GND directly or through a
very low resistance: In this case, the IMON pin voltage is held at a low
voltage and is not allowed to exceed the threshold (VIREF) even if
there is significant current flowing through the device, thereby rendering the
primary overcurrent protection mechanism ineffective. The device relies on an
internal overcurrent sense mechanism to provide some protection as a backup. If
the device detects that the backup current sense threshold (IOC_BKP)
is exceeded but at the same time the primary overcurrent detection on IMON pin
fails, the pin triggers single point failure detection and latches a fault. The
FET is turned off and the FLT pin is asserted.