TC1797_14 Datasheet, PDF (156/192 Pages) Infineon Technologies AG – 32-Bit Single-Chip Microcontroller

5.3.3 Power Sequencing
TC1797
Electrical Parameters
V
5V
3.3V
1.5V
V_DDP
+-5%
+-5%
0.5V
0.5V
+-5%
V_AREF
-12%
-12%
0.5V
t
PORST
power
down
power
fail
t
Power-Up 8.vsd
Figure 26 5 V / 3.3 V / 1.5 V Power-Up/Down Sequence
The following list of rules applies to the power-up/down sequence:
• All ground pins V_SS must be externally connected to one single star point in the
system. Regarding the DC current component, all ground pins are internally directly
connected.
• At any moment,
each power supply must be higher than any lower_power_supply - 0.5 V, or:
VDD5 > VDD3.3 - 0.5 V; VDD5 > VDD1.5 - 0.5 V;VDD3.3 > VDD1.5 - 0.5 V, see
Figure 26.
• During power-up and power-down, the voltage difference between the power supply
pins of the same voltage (3.3 V, 1.5 V, and 5 V) with different names (for example
VDDP, VDDFL3 ...), that are internally connected via diodes, must be lower than
100 mV. On the other hand, all power supply pins with the same name (for example
Data Sheet
152
V1.3, 2014-08