
Analog Integrated Circuit Device Data
Freescale Semiconductor
20
PC34708
General IC Functional Description and Application Information
Block Diagram
Control Interface
SPI/I2C communication protocol
6.3
Block Diagram
Figure 4. PC34708 - Functional Block Diagram
6.4
Functional Description
6.4.1
Switchers and Regulators
The PC34708 PMIC provides reference and supply voltages for the application processor as well as peripheral device.
Five buck (step down) converters and one boost (step up) converters are included. One of the buck switchers can be configured
in multiphase, single phase mode, or operate as separate independent outputs (in this case, there are 6 buck converters). The
buck converters provide the supply to processor cores and to other low voltage circuits such as IO and memory. Dynamic voltage
scaling is provided to allow controlled supply rail adjustments for the processor cores and/or other circuitry. The boost converter
provides power for the VBUS in the OTG mode, as well as the USB PHY on the processor. The VUSB regulator is powered from
the boost to ensure sufficient headroom for the LDO through the normal discharge range of the main battery.
Linear regulators are directly supplied from the battery or from the switchers, and include supplies for IO and peripherals, such
as audio, camera, Bluetooth, Wireless LAN, etc. Naming conventions are suggestive of typical or possible use case applications,
but the switchers and regulators may be utilized for other system power requirements within the guidelines of specified
capabilities. Four general purpose I/Os are available, which can be configured as inputs/outputs. As inputs they can be
configured as interrupts.
POWER
CONTROL LOGIC
State Machine
5 BUCK SWITCHERS
Processor Core
Split Power Domains
DDR Memory
I/O
8 LDO REGULATORS
5V BOOST
SWITCHER
USB On The Go
Supply
MINI/MICRO USB
USB/UART/Audio
10 BIT ADC CORE
General Purpose
Resistive Touch
GENERAL
Purpose I/O &
PWM Outputs
BIAS &
REFERENCES
BATTERY MANAGEMENT
CONTROL
INTERFACE
SPI/I2C
PC34708
Screen Interface
32.768 kHz
CRYSTAL
OSCILLATOR
Peripherals
Real Time Clock
SRTC Support
Trimmed Bandap
Single Cell Li-Ion Charger
Wall/USB Charger Input
OV/UV & Short Circuit Protection
Coin Cell Charger
Coulomb Counter
LED Charging/Fault Indicator
INTERFACE
Auto Accessory Detect