Datasheet

Analog Integrated Circuit Device Data
35 Freescale Semiconductor
MC34708
Functional Block Description
7.5 Power Generation
The MC34708 PMIC provides reference and supply voltages for the application processor as well as peripheral devices.
Six buck (step down) converters and one boost (step up) converter are included. One of the buck regulators can be configured
in dual phase, single phase mode, or operate as separate independent outputs (in this case, there are six 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
supplies the VUSB regulator for 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 could be supplied directly from the battery or from one of the switching regulator, and provide 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 switching and linear regulators may be utilized for other system power requirements within the
guidelines of specified capabilities.
Four general purpose I/Os are available. When configured as inputs they can be used as external interrupts.
7.5.1 Power Tree
Refer to the representative tables and text specifying each supply for information on performance metrics and operating ranges.
Table 22 summarizes the available power supplies.
Table 22. Power Tree Summary
Supply Purpose (typical application) Output Voltage (in V) Load Capability (in mA)
SW1
Buck regulator for processor VDDGP domain
0.650 - 1.4375 2000
SW2
Buck regulator for processor VCC domain
0.650 - 1.4375 1000
SW3
Buck regulator for processor VDD domain and peripherals
0.650 - 1.425 500
SW4A
Buck regulator for DDR memory and peripherals
1.200 – 1.85: 2.5/3.15 500
SW4B
Buck regulator for DDR memory and peripherals
1.200 – 1.85: 2.5/3.15 500
SW5
Buck regulator for I/O domain
1.200 – 1.85 1000
SWBST
Boost regulator for USB OTG
5.00/5.05/5.10/5.15 380
VSRTC
Secure Real Time Clock supply
1.2 0.05
VPLL
Quiet Analog supply
1.2/1.25/1.5/1.8 50
VREFDDR
DDR Ref supply
0.6-0.9 10
VDAC
TV DAC supply, external PNP
2.5/2.6/2.7/2.775 250
VUSB2
VUSB/peripherals supply, internal PMOS
2.5/2.6/2.75/3.0 65
VUSB/peripherals external PNP
2.5/2.6/2.75/3.0 350
VGEN1
General peripherals supply #1
1.2/1.25/1.3/1.35/1.4/1.45/1.5/1.55 250
VGEN2
General peripherals supply #2, internal PMOS
2.5/2.7/2.8/2.9/3.0/3.1/3.15/3.3 50
General peripherals supply #2, external PNP
2.5/2.7/2.8/2.9/3.0/3.1/3.15/3.3 250
VUSB
USB Transceiver supply
3.3 100