ACT81460
Rev 1.0, 18-Dec-2018
FUNCTIONAL DESCRIPTION
General
The ACT81460 is highly flexible and contains many I2C
configurable functions. The IC’s default functionality is
defined by its default CMI (Code Matrix Index), but
much of this functionality can be changed via I2C. I2C
functionality includes OV and UV fault thresholds,
switching frequencies, current limits, precharge and fast
charge current settings, charging termination voltage,
JEITA settings, and more. The CMI Options section
shows the default settings for each available CMI option.
Contact sales@active-semi.com for additional infor-
mation about other configurations.
The ACT81460 is optimized for low power battery
applications, but can also be used in higher power
applications requiring small size with high integration.
The ACT81460 has one main power input, the VIN pin.
This input supply is passed through the Smart Switch
which serves three functions: VSYS softstart, VSYS
linear regulator, and VIN overvoltage blocking. VSYS is
the system voltage, which is limited to a maximum of
5.5V by the Smart Switch. The VSYS output powers the
rest of the system and the other converters. The smart-
switch doubles as a linear regulator to regulate VSYS to
voltages lower than VIN.
I2C Serial Interface
The ACT81460 powers the system with several buck
converters, a buck-boost converter, a boost converter,
three LDOs, and three load switches. All of these are
fully integrated and highly configurable. The buck
converters each provide 400mA. The buck-boost can be
configured in either buck-boost mode or boost mode
and provides up to 400mA of output current. The boost
converter provides up to 20V and can be configured in
either voltage or current mode. In voltage mode, it
powers higher voltage loads. In current mode, it
regulates a constant current to a string of LEDs. The
three LDOs provide up to 100mA. LDO3 is also
configurable as a load switch. All three LDOs have
dedicated input power pins to help optimize overall
system efficiency. The three load switches provide very
flexible system level power sequencing and allow the
user to design voltage “islands” to turn off parts of the
system in low power modes.
To ensure compatibility with a wide range of systems,
the ACT81460 uses standard I2C commands. It sup-
ports clock speeds up to 1MHz. The ACT81460 always
operates as a slave device, and can be factory config-
ured to one of four 7-bit slave addresses. The 7-bit slave
address is followed by an eighth bit, which indicates
whether the transaction is a read-operation or a write-
operation. Refer to each specific CMI for the IC’s slave
address
Table 1: ACT2861 I2C Addresses
7-Bit Slave Address
8-Bit Write
Address
0x4Ah
0x4Eh
0xCEh
8-Bit Read
Address
0x4Bh
0x4Fh
0xCFh
0x25h
0x27h
0x67h
0x6Bh
010 0101b
010 0111b
110 0111b
110 1011b
0xD6h
0xD7h
I2C commands are communicated using the SCL and
SDA pins. SCL is the I2C serial clock input. SDA is the
data input and output. SDA is open drain and must have
a pull-up resistor. Signals on these pins must meet tim-
ing requirements in the Electrical Characteristics. For
more information regarding the I2C 2-wire serial inter-
face, refer to the NXP website: http://www.nxp.com.
The ACT81460 also contains a configurable linear
charger that provides up to 800mA. It is fully JEITA
compliant and autonomously charges a single cell Li-
Ion battery. It contains a full complement of charging
protection features to ensure safe and reliable operation.
The ACT81460’s four GPIOs can be configured for a
variety of functions. They can be used as standard
digital inputs, push-pull outputs, open drain outputs,
LED drivers, or as analog input/outputs. Typical
configurations include nRESET, Power Good (PG),
interrupt request or interrupt pin (nIRQ), digital output
from power okay (POK) signal from individual regulators,
digital input to control power sequencing or regulator
ON/Off, digital inputs to put the IC into SLEEP and
DPSLP modes, input/output lines to sequence external
regulators as part of the power sequence, Dynamic
Voltage Scaling (DVS) inputs, and as LED drivers.
I2C Registers
The ACT81460 has an array of internal registers that
contain the IC’s basic instructions for setting up the IC
configuration, output voltages, switching frequency,
fault thresholds, fault masks, etc. These registers give
the IC its operating flexibility. The two types of registers
are described below.
Basic Volatile – These are R/W (Read and Write) and
RO (Read only). After the IC is powered, the user can
modify the R/W register values to change IC functional-
ity. Changes in functionality include things like masking
certain faults. The RO registers communicate IC status
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