
Analog Integrated Circuit Device Data
Freescale Semiconductor
45
PC34708
Functional Block Requirements and Behaviors
Power Control Logic Block Description and Application Information
With MBATT replaced by short, GBAT is grounded. The application powers up and the buck input current limit is set to 950 mA,
the constant current setting. All the charger timers are disabled. If the ILIM_1P5 SPI bit is set, the constant current charger current
setting will be set to 1500 mA, as will the input current limit.
In factory mode, input current regulation and thermal fold back regulation will be disabled. The input mode regulation interrupts
and the thermal fold back will assert, when the condition exists (if enabled and unmasked). With these interrupts, the processor
can take action to reduce the system current.
7.2
Power Control Logic Block Description and Application
Information
Figure 8. Power Control State Machine Flow Diagram
Off
On
User
Off
Memory
Hold
Warm
Start
Watchdog
Cold
Start
User Off
Wait
Internal
MemHold
Power
Cut
From any mode: Loss of Power with PCEN=0
Thermal Protection Trip, or System Reset
Unqual’d
Turn On
WDI Low,
WDIRESET=0
Unqual’d
Turn On
Event
PCT[7:0] Expired
WDI Low
WDIRESET=1
and PCMAXCNT
is exceeded
WDI Low
WDIRESET=1
and PCMAXCNT
is not exceeded
Start Up Modes
Reset Timer
Expired
Reset Timer
Expired
Watchdog Timer
Expired
Turn On Event
(Warm Boot)
Turn On Event
(Warm Start)
Processor Request
for User Off:
USEROFFSPI=1
PCUT Timeout
PCT[7:0]
Expired
PCUTEXPB
cleared to 0
Low Power
Off Modes
Warm Start
Enabled
Warm Start
Not
Enabled
WARMEN=1
WARMEN=0
Application of Power
before PCUT Timer
PCT[7:0] expiration
(PCEN=1 and
PCMAXCNT not
exceeded)
From any mode: Loss of Power
with Power Cuts enabled
(PCEN=1) and PCMAXCNT
not exceeded
Legend and Notes (refer to text for additional details)
Blue Box = Steady State, no specific timer is running
Green Circle = Transitional State, a specific timer is running, see text
Dashed Boxes = Grouping of Modes for clarification
WDI has influence only in the “On” state
Complete loss of BP and coin cell power is not represented in the state machine