Functional pin description

STBC03

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DocID029927 Rev 2

6.9

SYS

The internal LDO input voltage and external unregulated supply pin. The maximum current

deliverable through this pin depends on the following two conditions: LDO load and battery

status. However, if none of the above loads sinks current, the maximum SYS current

budget is 650 mA, provided that the input voltage source can deliver that amount of

current.

SYS voltage source can be either IN or BAT, depending on the operating conditions (refer

to the following table). A ceramic bypass capacitor of 1 µF must be connected to GND.

Table 7: SYS voltage source

SYS status

LDO status

< VODC(1)

Not powered

Off

VBAT(2)

On

X (don’t care)(3)

On

Not powered

Off

VBAT(2)

On

Notes:

6.10

LDO

LDO output voltage pin. The maximum current capability is anyhow 150 mA. A 1 µF

ceramic bypass capacitor must be connected to GND.

6.11

WAKE-UP

Wake-up input pin. To restore normal operations of the STBC03, so to exit from a

shutdown condition, connect the WAKE-UP pin to the battery voltage. The STBC03 is

enabled to operate in normal conditions again, only if the battery voltage is higher than

above-described WAKE-UP pin functionality is disabled when a valid VIN voltage source is

detected. The pin has an internal 50 kΩ pull-down resistor.