Datasheet

Vybrid Power Consumption and Options, Rev. 0
Freescale Semiconductor 9
Powering options
8 Powering options
LDO or DC/DC converters can be used. The correct selection depends on the maximal current taken from
a selected branch or rail.
8.1 Vybrid power rails
Vybrid requires up to four different voltages; the first two are essential:
• 3.3V for input/output pins and internal LDOs
• 1.2V for core power supply and video ADC analog front end
• 1.2V/1.5V for SDRAM interface (optional)
• 5V for USB (optional)
Two power rails must be supplied for normal run. The first power rail is 1.2V for the core. This rail is also
used for Video ADC analog front end. The second rail used is 3.3V voltage level for input/output pins and
to power Vybrid internal LDOs. The 1.2V supply voltage can be stabilized using the internal LDO
regulators (LPREG) for low power modes or with the internal LDO control with the external ballast
transistor (HPREG) for the normal run mode. If SDRAM (LP-DDR2 or DDR3) is used, an additional
power supply is needed. The voltage level depends on the type of memory used. In the case of LP-DDR2,
it is 1.2V. In the case of DDR3, it is 1.5V. If USB is used in host mode, a 5V voltage level is needed to
provide VBUS. 5V is usually power source for 3.3V and 1.5V DC/DC converters.
The block scheme of the internal Vybrid power configuration and the recommended external circuit are
shown in the Figure 3. The block scheme is taken from the Vybrid datasheet.