Datasheet

18
32133D–11/2011
UC3D
4.2.3.2 3.3V + 1.8V Dual Supply Mode
In dual supply mode the internal regulator is not used (unconnected), VDDIO is powered by 3.3V
supply and VDDCORE is powered by a 1.8V supply as shown in Figure 4-3.
Figure 4-3. 3.3V + 1.8V Dual Power Supply Mode.
4.2.4 Power-up Sequence
4.2.4.1 Maximum Rise Rate
To avoid risk of latch-up, the rise rate of the power supplies must not exceed the values
described in Supply Characteristics table in the Electrical Characteristics chapter.
Recommended order for power supplies is also described in this table.
4.2.4.2 Minimum Rise Rate
The integrated Power-Reset circuitry monitoring the VDDIN powering supply requires a mini-
mum rise rate for the VDDIN power supply.
VDDIO
VDDOUT
CPU,
Peripherals,
Memories,
SCIF, BOD,
RCSYS,
PLL
Linear
Regulator
+
-
3.0-3.6V
VDDANA
ADC
VDDIN GND
GNDANA
I/O Pins
+
-
3.0-3.6V
VDDCORE
1.65-1.95V
+
-