Datasheet

DocID024654 Rev 2 21/29
STNS01 Operation description
8.6 Battery discharge overcurrent protection
When the STNS01 is powered from the BAT pin, a discharge overcurrent protection circuit
disables the device if the battery current exceeds I
BATOCP
for more than t
DOD
. A valid input
voltage (V
IN
) must be connected to restore normal operating conditions.
8.7 Input overcurrent protection
When the STNS01 is powered from the IN pin, a current limitation circuit prevents the input
current from increasing up to potentially destructive values. When V
SYS
is lower than
V
ILIMSCTH
, the input current is limited to I
INLIMSC
in order to have reduced power dissipation
in short-circuit conditions. As soon as V
SYS
increases over V
ILIMSCTH
, the current limitation
value is increased to I
INLIM
.
8.8 SYS and LDO short-circuit protection
In case of an abrupt short-circuit on SYS or LDO, the STNS01 is immediately turned off (no
deglitch). This short-circuit protection intervenes when the SYS voltage drops below V
SCSYS
or the LDO output voltage drops below V
SCLDO
.
8.9 IN overvoltage protection
The STNS01 is normally powered from the battery when V
IN
> V
INOVP
while it is powered
from the IN pin when V
UVLO
< V
IN
< V
INOVP
. In the latter case, if the input voltage temporarily
increases over V
INOVP
due to a poorly regulated power supply, the STNS01 switches to
battery power to protect any external circuit connected to SYS.
If the input voltage (V
IN
) returns into the normal range, the device's supply voltage is
switched back to the IN pin.
8.10 Shutdown mode
A high level on the shutdown digital input pin (SD) when no valid input voltage is connected
makes the device enter shutdown (low power) mode. Battery drain is then reduced to less
than 500 nA. The exit conditions for the shutdown mode are the same as for the
overdischarge state (valid V
IN
connected and V
BAT
> V
ODCR
).
8.11 Thermal shutdown
The STNS01 is protected against overheating which might be generated by the combination
of ambient temperature and internal heating due to power dissipation. When the die
temperature exceeds T
SD
the device is turned off.
In order to restore normal operation the input voltage (V
IN
) must be disconnected and re-
connected.