STBC03 Datasheet, PDF (29/34 Pages) STMicroelectronics – Li-Ion linear battery charger with LDO and load switches

STBC03
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8.9
8.10
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8.12
8.13
8.14
Floating voltage adjustment
Operation description
The STBC03 features a floating voltage adjustment, controlled via the external resistor
RFLOAT connected between battery and BATSNSFV. For safety reasons, the battery voltage
overcharge threshold level (VOCHG) is linked to any floating voltage set.
Input overcurrent protection
When the STBC03 is powered off from a valid input voltage source, a current limitation
circuit prevents the input current from increasing in an uncontrolled manner in case of
excessive load. In fact, when VSYS is lower than VILIMSCTH, the input current is limited so to
have a reduced power dissipation. As soon as VSYS increases over VILIMSCTH, the input
current limit value is increased to IINLIM.
SYS short-circuit protection, LDO current limitation
In battery mode condition, if a short-circuit on the SYS pin happens, the STBC03 is turned
off (no deglitch). This short-circuit protection occurs until the SYS voltage drops below
VSCSYS.
If the LDO output is in a short-circuit condition, the maximum delivered current is limited to
ISC.
IN overvoltage protection
Should the input voltage source temporarily be VIN>VINOVP (for example due to a poorly
regulated voltage source), then the STBC03 is powered off from the battery, thus any load
connected to SYS is protected.
As soon as the input voltage source goes back within a valid input range (VUVLO < VIN <
VINOVP), the STBC03 is then powered off again from VIN.
Shutdown mode
Asserting the SD pin high forces the STBC03 to enter in shutdown mode (low power), the
current sunk from the battery is reduced to less than 50 nA. Both SYS and LDO pins are
not supplied. Normal operating conditions are restored either by connecting a valid input
voltage source (VUVLO<VIN < VINOVP) for at least tPW-VIN or by connecting the WAKE-UP pin to
VBAT for at least tPW-WA.
Thermal shutdown
The STBC03 is fully protected against overheating. During the charging process, if a TWRN<
TSD temperature level is detected, a warning is signaled via the CHG output (toggling at
14.2 Hz). In this condition, the programmed IPRE and IFAST are temporary halved. In case of
a further temperature increase (up to TSD) the STBC03 turns off, thus stopping the charging
process. This condition is latched and normal operation can be restored only by
disconnecting and reconnecting back again a valid input voltage source on the VIN pin.
Reverse current protection
When the input voltage (VIN) is higher than VUVLO, but lower than the battery voltage VBAT
(VUVLO < VIN < VBAT) the current path from BAT to IN is opened so to stop any reverse
current flowing from the battery to the input voltage source. This event is signaled through
the CHG flag.
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