DocID023755 Rev 4

19/31

STC3115

Functional description

31

Figure 11. BATD and RSTIO

The BATD/CD pin used as a battery detector is an analog I/O.The input detection threshold

is typically 1.61V.

impedance.

The RSTIO/BATD signal is used to control the application system reset during the initial

OCV measurement. The RSTIO/BATD pin is a standard I/O pin with open drain output.

BATD/CD can be connected to the NTC sensor or to the identification resistor of the battery

pack. The STC3115 does not provide any biasing voltage or current for the battery

detection. An external pull-up resistor or another device has to pull the BATD/CD pin high

when the battery is removed.

Figure 12. BATD/CD pin connection when used as battery detector

BATD/CD

RSTIO/BATD

VCC

BATD_drive_high

BATD_comp_out

RSTI

RSTO

1.61 V

+

-

STC3115

STC3115

Other biasing

and/or detection

circuit

Battery

pack

BATD/CD

Rid

BATD biasing by external circuitry

BATD resistor biasing

Battery pack

Rid

Ru

(>1 M)

1K

1K

BATD/CD