®
ACT5830
Rev 2, 20-Jan-11
SYSTEM MANAGEMENT
FUNCTIONAL DESCRIPTIONS
The ACT5830 offers a wide array of system
management functions that allow it to be configured for
optimal performance in a wide range of applications.
(LDO5), TX_EN (LDO6), and PWR_HOLD (REG
and LDO1) pins.
This start-up procedure requires that the push-
button be held until the microprocessor assumes
control of PWR_HOLD, providing protection against
inadvertent momentary assertions of the push-
button. If desired, longer “push-and-hold” times can
be easily implemented by simply adding an
additional delay before assuming control of
PWR_HOLD. If the microprocessor is unable to
complete its power-up routine successfully before
the user lets go of the push-button, the ACT5830
will automatically shut itself down.
I²C Serial Interface
At the core of the ACT5830’s flexible architecture is
an I2C interface that permits optional programming
capability to enhance overall system performance.
Use standard I2C write-byte commands to program
the ACT5830 and read-byte commands to read the
IC’s status. Figure 1: I2C Serial Bus Timing provides
a standard timing diagram for the I2C protocol. The
ACT5830 always operates as a slave device, with
address 1010101.
Once a successful power-up routine is completed,
the user can initiate a shutdown process by
pressing the push-button a second time. Upon
detecting a second assertion of PWR_ON (by
depressing the push-button), the ACT5830 asserts
nON to interrupt the microprocessor which initiates
an interrupt service routine that will reveal that the
user pressed the push-button. If HF_PWR and
CHG_OK are both low, the microprocessor then
initiates a power-down routine, the final step of
which will be to de-assert PWR_HOLD, disabling
REG and LDO1.
System Startup & Shutdown
The ACT5830 features
a
flexible enable
architecture that allows it to support a variety of
push-button enable/disable schemes. Although
other startup routines are possible, a typical startup
and shutdown process would proceed as follows
(referring to Figure 2):
System startup is initiated whenever one of the
following conditions occurs:
1) The user presses the push-button, asserting
PWR_ON high,
Open Drain Outputs
2) A valid supply (>4V) is connected to the
charger input (CHG_IN), or
The ACT5830 includes two n-channel open drain
outputs (OD1 and OD2) that can be used for driving
external loads such as WLEDs or a vibrator motor,
as shown in the functional diagram. Each of the OD
outputs is enabled when either it's respective ODIx
pin in driven to a logic high.
3) A headset is connected, asserting HF_PWR
high.
The ACT5830QJ1CF begins its system startup
procedure by enabling REG, LDO7 and LDO8, then
LDO1 are enabled when VBUCK reaches 87% of
its final value; The ACT5830QJ182 begins its
system startup procedure by enabling REG, LDO1,
LDO7 and LDO8. nRST is asserted low when
VOUT1 reaches 87% of its final value, holding the
microprocessor in reset for a user-selectable reset
period of 65ms. If VBUCK and VOUT1 are within
13% of their regulation voltages when the reset
timer expires, the ACT5830 de-asserts nRST so that
the microprocessor can begin its power up
sequence. Once the power-up routine is successfully
completed, the microprocessor asserts PWR_HOLD
high to keep the ACT5830 enabled after the push-
button is released by the user.
nACOK Output
The ACT5830's nACOK output provides a logic-level
indication of the status of the voltage at CHG_IN.
nACOK is an open-drain output which sinks current
whenever VCHG_IN > 4V.
Thermal Overload Protection
The ACT5830 integrates thermal overload protection
circuitry to prevent damage resulting from excessive
thermal stress that may be encountered under fault
conditions, for example. This circuitry disables all
regulators if the ACT5830 die temperature exceeds
160°C, and prevents the regulators from being
enabled until the die temperature drops by 20°C
(typ), after which a normal startup routine may
commence.
Once the power-up routine is completed, the
remaining LDOs can be enabled/disabled via either
the I2C interface or the TCXO_EN (LDO4), RX_EN
Innovative PowerTM
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