Electrical Characteristics
MFR4310 Reference Manual, Rev. 2
238 Freescale Semiconductor
A.1.2 Power Supply
The MFR4310 uses several pins to supply power to the I/O pins, oscillator and the digital core.
The VDDA, VSSA pair supplies the internal voltage regulator.
The VDDX, VSSX, VDDR and VSSR pairs supply the I/O pins, VDDR supplies also the internal voltage
regulator.
VDD2_5 and VSS2_5 are the supply pins for the digital logic, VDDOSC, VSSOSC supply the oscillator.
VDDA, VDDX, VDDR as well as VSSA, VSSX, VSSR are connected by anti-parallel diodes for ESD
protection.
NOTE
In the following context, VDD5 is used for VDDA, VDDR, and VDDX;
VSS5 is used for VSSA, VSSR, and VSSX unless otherwise noted.
IDD5 denotes the sum of the currents flowing into the VDDA, VDDX, and
VDDR pins.
VDD is used for VDD2_5 and VDDOSC; VSS is used for VSS2_5 and
VSSOSC.
IDD is used for the current flowing into VDD2_5.
A.1.3 Pins
There are four groups of functional pins.
A.1.3.1 3.3V I/O pins
Those I/O pins have a nominal level of 3.3V. This class of pins is comprised of all I/O pins (all MFR4310
pins excluding EXTAL, XTAL and all power supply pins).The internal structure of all those pins is
identical, however some of the functionality may be disabled. E.g. for the input-only pins the output
drivers are disabled permanently.
A.1.3.2 Oscillator
The pins EXTAL, XTAL dedicated to the oscillator have a nominal 2.5V level. They are supplied by
VDDOSC.
A.1.3.3 VDDR
This pin is used to enable the on chip voltage regulator.
A.1.4 Current Injection
Power supply must maintain regulation within operating V
DD5
or V
DD
range during instantaneous and
operating maximum current conditions. If positive injection current (V
in
> V
DD5
) is greater than I
DD5
, the
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