STBC03 datasheet(29/34 Pages) STMICROELECTRONICS

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STBC03

Operation description

DocID029927 Rev 2

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8.8

Floating voltage adjustment

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.

8.9

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.

8.10

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.

8.11

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.

8.12

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.

8.13

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.

8.14

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.

STBC03 数据表(PDF) 29 Page - STMicroelectronics

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