STBP120

Pin descriptions

Doc ID 15492 Rev 4

9/36

Figure 3.

Block diagram

Figure 4.

(2)

1.

required. Low ESR ceramic capacitor C1 is necessary to ensure proper function of the STBP120. Capacitor C2 is not

necessary for STBP120 but may be required by the charger IC.

2.

The STBP120 MOSFET switch topology allows the current to also flow in the reverse direction, from OUT to IN, which can

be useful for powering external peripherals from the system connector. The charger IC should not contain the reverse

diode to prevent the battery pack voltage from appearing on the system connector. If the reverse current (supply current) is

undesirable, it may be prevented by connecting a Schottky diode in series with the OUT pin. The voltage drop between IN

and charger is increased by the voltage drop across the diode.

GND

FLT

EN

IN

OUT

COUNTERS

OFF

VREF

VCC

AM00306

CONTROL LOGIC

SUPPLY

REGULATOR

OSCILLATOR

CHARGE PUMP

MOSFET DRIVER

VOLTAGE

REFERENCE

Input overvoltage

Input undervoltage

Thermal shutdown

Temperature

detector

MCU

INTERFACE

ESD

protection

ESD

protection

ESD

protection

Core

negative

protection

AM00314a

AC

adapter

POWERED

PERIPHERALS

SYSTEM

CONNECTOR

SUPPLY CURRENT

CHARGING CURRENT

C1

1 µF

IN

OUT

FLT

EN

GND

EN

ENABLE

C2

1 µF

RFLT

REN

RPU

CHARGER

IC

SUPPLY

CIRCUITS

CONTROLLER

BATTERY

PACK

STBP120

APPLICATION

DC-DC

OR

PERIPHERAL