TC1767
Electrical Parameters
5.3.3
Power Sequencing
V
+-5%
5V
VAREF
+-5%
3.3V
1.5V
-12%
+-5%
0.5V
-12%
0.5V
0.5V
t
VDDP
PORST
power
down
power
fail
t
Power-Up 8.vsd
Figure 24
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 VSS must be externally connected to one single star point in the
system. Regarding the DC current component, all ground pins are internally directly
connected.
1. 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 24.
2. 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 internaly connected via diodes must be lower than 100 mV.
On the other hand, all power supply pins with the same name (for example all VDDP
), are internaly directly connected. It is recommended that the power pins of the same
voltage are driven by a single power supply.
Data Sheet
102
V1.3, 2009-09
INFINEON [ Infineon ]
