ACT81460
Rev 1.0, 18-Dec-2018
PIN FUNCTIONS
NTC
VIN
NTC is the battery temperature sense input. Connect a
negative temperature coefficient thermistor from NTC to
AGND. This pin provides a constant current output and
the resulting voltage at this pin is used to calculate the
battery temperature.
VIN is the ACT81460 input power pin. The VIN operat-
ing range is 4.0V to 5.5V, but it withstands voltage
surges up to 20V.
VIN power the Smart Switch, two back-to-back protec-
tion FETs that actively disconnect VIN from VSYS when
the input voltage goes above 5.8V. The Smart Switch
also acts as a linear regulator to control the VSYS volt-
age, which powers the linear charger and other power
rails. The regulated Smart Switch regulates VSYS to
4.8V.
VINLx
The VINL123 pins are dedicated input pins for LDO1,
LDO2, and LDO3. The three LDO inputs are independ-
ent from each other. They can be connected to the
same or to different input voltage rails. The VINL123
voltages should be higher than their respective LDO
output voltages to maintain regulation. Connect 1uF ce-
ramic input bypass capacitor directly between each
VINL123 pin and PGND.
Connect a 1uF ceramic input bypass capacitor directly
between VIN and PGNDx
VSYS
VSYS is the output of the Smart Switch. It powers the
rest of the system, the linear charger, and the switching
converters. Connect a 10uF ceramic bypass capacitor
from VSYS to PGND.
SWx
The SWx pins are the switch nodes for their respective
switching converters. Connect the inductors directly to
the SWx pins.
VBAT
VBST
The VBAT pins are the output of the linear charger. Note
that the battery voltage is not regulated at VBAT, but at
the VBATS pin. Connect 10uF ceramic output bypass
capacitor directly between VBAT and PGND.
VBST is the boost converter output pin. The VBST pin
must have a dedicated ceramic bypass capacitor that is
connected to PGND. Proper capacitor selection and
placement are critical to good power supply perfor-
mance.
VBATS
VBATS is the battery voltage sense pin. The battery
voltage is regulated at the VBATS pin. Kelvin connect
input VBATS as close to the battery input terminals as
possible.
ISNS
ISNS is the current sensing input pin for the boost con-
verter when it is configured for a constant current output.
Connect the return side of the constant current load to
ISNS. The load’s return side is typically the cathode of
an LED string. Note that ISNS is always regulated to
0.25V.
OUTLx
The OUTLx pins are the outputs of the LDO linear reg-
ulators. These are also LDO regulation points.
VINLSx
VINBx
The VINLS456 pins are dedicated input pins for Load
Switch 4, 5, and 6. Connect 1uF ceramic input bypass
capacitor directly between each VINLS123 pin and
ground. The capacitor’s ground should be connected to
load switch’s input supply’s output capacitor’s ground.
The VINBx pins are the inputs to the buck and buck-
boost regulators. Each pin is a dedicated input to its
switching regulator. The VINBx pins must be directly
connected to the VSYS output. Each VINBx pin must
have a dedicated ceramic bypass capacitor that is con-
nected to PGND. Proper capacitor selection and place-
ment are critical to good power supply performance.
GPIOx
The GPIOx pins can be configured as inputs, outputs,
or other special functions. See the GPIO Functionality
section of the DS for more details.
ISET
ISET sets the maximum battery charge current. Con-
nect a 1.2kohm to 15kohm resistor between ISET and
AGND to set the fast charge current. See the Active
Path Linear Charger section for more information.
NC
This pin is not internally connected to the IC. It can be
left open, shorted to GND, or shorted to the VIO_IN pin.
Active Semi recommends shorting NC to VIO_IN.
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ActiveSwitcherTM is a trademark of Active-Semi
www.active-semi.com
Copyright © 2018 Active-Semi, Inc.
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