SRC0 datasheet(10/48 Pages) STMICROELECTRONICS

10 / 48 page

Pin descriptions

SRC0

10/48

DocID026008 Rev 2

PB - power ON switch

This input is equipped with a voltage detector with a factory-trimmed threshold and has

± 8 kV HBM ESD protection.

When the PB button is pressed and held, the battery voltage is detected and EN (or EN) is

asserted if the battery voltage is above the threshold VTH+ during the whole tDEBOUNCE

period (see Figure 13).

A short push of the push-button during normal operation can initiate an interrupt through

debounced INT output (see Figure 14) and a long push of PB and SR simultaneously can

either assert reset output RST (see Figure 18) or deassert the EN or EN output (see

Figure 19) based on the option used.

Note:

A switch to GND must be connected to this input (e.g. mechanical push-button, open drain

output of external circuitry, etc.), see Figure 1. This ensures a proper startup signal on PB

(i.e. a transition from full VCC below specified VIL). PB input has an internal 100 k pull-up

resistor connected.

VCCLO - high threshold detection output

During power-up, VCCLO is low when VCC supply voltage is below the VTH+ threshold. After

successful power-up (i.e. during normal operation) VCCLO is low anytime undervoltage is

detected (see Figure 13).

Output type is active low and open drain by default. Open drain output type requires a pull-

up resistor. A 10 k

 is sufficient in most applications.

VCCLO is floating when SRC0 is in standby mode.

PBOUT - PB input state

If the push-button PB is pressed, the pin stays low during the tDEBOUNCE time period.

If PB is asserted for the entire tDEBOUNCE period, PBOUT will then stay low for at least

tINT_Min. If PB is asserted after tINT_Min expires, PBOUT will return high as soon as PB is

deasserted (see Figure 22). PBOUT ignores PB assertion during an undervoltage condition.

At startup on the SRC0 PBOUT will respond only to the first PB assertion and any other

assertion will be ignored until tON_BLANK expires. This output is active low and open drain by

default. Open drain output type requires a pull-up resistor. A 10 k

 is sufficient in most

applications.

SRC0 데이터시트(PDF) 10 Page - STMicroelectronics