TC1765 Datasheet, PDF (58/88 Pages) Infineon Technologies AG – 32-Bit Single-Chip Microcontroller

TC1765
Preliminary
Ports Power Supply
The TC1765’s port power supply concept is shown in Figure 19. The External Bus Unit
(EBU) I/O lines are in the core and EBU V_DD power supply group for 2.5 V nominal
operating voltage. The general purpose input/outputs (GPIOs) provide 3.3 to 5 V nominal
voltage input/output acceptance and drive characteristics.
V_DD
(2.5 V)
V_DDP
(3.3 - 5 V)
V_SS
EBU I/O Lines
(Pads)
&
Schmitt Trigger
Ports 0 to 5
(Pads)
&
Schmitt Trigger
Port Logic
MCA05226
Figure 19 Ports Power Supply Concept
Power-up Sequence
During Power-up the reset pin PORST has to be held active until both power supply
voltages have reached at least their minimum values.
During the Power-up time (rising of the supply voltages from 0 to their regular operating
values) it has to be ensured, that the difference between V_DDP and V_DD never drops
below -0.5 V.
Power Loss
If V_DDP is dropping below V_DD, external circuitry in the power supply has to ensure, that
V_DD is also limited to the same level.
If V_DDI is dropping below the operating range, V_DDP may stay active.
Powering Down
During powering down (falling of the supply voltages from their regular operating values
to zero), it has to be ensured, that the difference between V_DDP and V_DD never drops
below -0.5 V.
Data Sheet
54
V1.2, 2002-12