TC1791 Datasheet, PDF (123/153 Pages) Infineon Technologies AG – 32-Bit Single-Chip Microcontroller

5.3.2 Power Sequencing
TC1791
Electrical ParametersAC Parameters
V
5V
3.3V
1.3V
5.25V
4.75V
3.47V
3.0V
1.365V
1.235V
V_DDP
0.5V 0.5V
V_AREF
-12%
-12%
0.5V
t
PORST
power
down
power
fail
t
Power-Up 10.vsd
Figure 14 5 V / 3.3 V / 1.3 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 in time to avoid increased latch-up risk,
each power supply must be higher then any lower_power_supply - 0.5 V, or:
V_DD5 > V_DD3.3 - 0.5 V; V_DD5 > V_DD1.3 - 0.5 V;V_DD3.3 > V_DD1.3 - 0.5 V, see Figure 14.
– The latch-up risk is minimized if the I/O currents are limited to:
– 20 mA for one pin group
– AND 100 mA for the completed device I/Os
– AND additionally before power-up / after power-down:
1 mA for one pin in inactive mode (0 V on all power supplies)
• During power-up and power-down, the voltage difference between the power supply
pins of the same voltage (3.3 V, 1.3 V, and 5 V) with different names (for example
V_DDP, V_DDFL3 ...), 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 all V_DDP),
Data Sheet
116
V 1.1, 2014-05