Intel PXA27X manual Batteries, Main Battery, Backup Battery

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Intel® PXA27x Processor Family Power Requirements

these supplies must come up at the required voltage to operate reliably and to avoid damage to the external components. VCC_IO must be the highest potential of the system I/O supplies1. VCC_IO can be connected to any of VCC_LCD, VCC_MEM, VCC_USIM, VCC_USB and VCC_BB, but none of these supplies can exceed VCC_IO.

The power-up voltage requirement must be communicated by some input strapping mechanism on the PMIC if a PMIC can provide more than one voltage level for any of these domains. This ensures that each regulator powers up to its designated voltage without processor intervention. Software must read this configuration information using an I2C command.

2.2Batteries

The PXA27x processor supports a variety of system battery configurations with both a main battery and backup battery, and a main battery alone.

In systems with only a main battery, the main battery must drive VCC_BATT directly or use a regulator. In systems with a backup battery, the backup battery connects directly to VCC_BATT or the backup battery can be connected to a power controller, which in turn drives the PXA27x processor VCC_BATT.

2.2.1Main Battery

The main battery is a rechargeable single cell (or multiple cells in parallel) using lithium-ion or lithium-polymer technology. These batteries typically present a voltage as high as 4.2 V when fully charged, declining to under 3.0 V as they discharge. A main battery capacity of 500 to 1200 mAh is typical for most applications.

2.2.2Backup Battery

The backup battery is a lithium or lithium-manganese coin cell with an output voltage of approximately 3.0 V. The backup battery is a small rechargeable coin cell permanently mounted to the printed circuit board (PCB) in many handset applications. The PMIC must include a regulator and associated circuitry for recharging this type of backup battery. The two backup battery configurations are shown in Table 6.

1.excluding VCC_BATT and VCC_USB

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Application Note

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Contents Intel PXA27x Processor Family Power Requirements Application NoteApplication Note Contents Figures Introduction Naming ConventionsPower Domain Enable1 Units Specified Levels Tolerance Volts Intel PXA27x Processor Power Supply DomainsExternal Power Supply Descriptions Sram PLLPxtal DMAPower Domains and System Voltage/Current Requirements Intel PXA27x Processor Power SuppliesIntel PXA27x Processor Voltage Domains Sheet 1 Voltage DescriptionPower Supply Configuration in a Minimal System Intel PXA27x Processor Voltage Domains Sheet 2Intel PXA27x Processor Vcccore Supply Current Modeling Intel PXA27x processor power consumptionRegulators Required to Power the Intel PXA27x Processor Regulator DescriptionIntel PXA27x Processor Vcccore Supply Current Supply Current For Each Power DomainFrequency Dhrystones Power MPEG4 Decode Power Stress Name Functional Units Current mA @ Power Default Reset ValuesIntel PXA27x Processor Supply Current For Each Power Domain VccbattBatteries Main BatteryBackup Battery Backup Battery Description Battery Chargers and Main PowerPossible Backup Battery Configurations Typical Battery and External Regulator Configuration Intel PXA27x Processor Low Power Operating Modes Intel PXA27x Processor Operating ModesCPDIS=0 Power Controller Interface SignalsCPDIS=1 Power Manager I2C Clock Pwrscl / GPIO3 Power Enable PwrenSystem Power Enable Sysen / GPIO2 Power Controller Interface SignalsUser-Initiated Hard Reset Input Power Manager I2C Data Pwrsda / GPIO4On, Off, and Reset System-Level Considerations for I2CUniversal Subscriber Identity Module Usim Power Manager Capacitor SignalsNRESET Output from Pmic to the Intel PXA27x Processor Cold-Start Power-On and Hardware Reset Power Mode SequencingPower-On Initial Power Up and Deep Sleep Exit Sequence Vcccore Vccpll VccsramHardware Reset Behavior Intel PXA27x Processor Family Power Requirements Sysdel PwrdelSleep and Deep Sleep Sleep Entry and ExitDeep Sleep Entry and Exit Dynamic Voltage Management DVM Vcccore Regulator and Dynamic Voltage ManagementIntel PXA27x Processor Voltage Manager NVDDFAULT Fault ManagementPower Manager I2C Interface DVM SequencingGeneral Pmic Characteristics Power Management Integrated Circuit RequirementsNBATTFAULT Characteristic Description Features of a PmicGeneral Pmic Characteristics Programmable Voltage Control DVM Control RegisterDVM Control and Status Register Other Aspects of an Integrated Power ControllerSummary Intel PXA27x Processor Family Power Requirements
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