
PEB 20324
PEF 20324
Electrical Characteristics
Hardware Reference Manual
37
04.99
5
Electrical Characteristics
5.1
Important Electrical Requirements
V
DD3
= 3.3 V
±
0.3 V
V
DD5
= 5.0 V
±
0.25 V
During all MUNICH128X power-up and power-down situations the difference
|
V
DD5
–
V
DD3
| may not exceed 3.6V. The absolute maximums of V
DD5
and V
DD3
should
never be exceeded.
Figure 5-1 shows that both V
DD3
and V
DD5
can take on any time sequence not exceeding
a voltage difference of 3.6V, for up to 50 milliseconds at power-up and power-
down.Within 50 milliseconds of power-up the voltages must be within their respective
absolute voltage limits. At power-down, within 50 milliseconds of either voltage going
outside its operational range, the voltage difference should not exceed 3.6V and both
voltages must be returned below 0.1V:
V
DD3 max
= 3.6 V
V
DD5 max
= 5.25 V
Figure 5-1
Power-up and Power-down scenarios
3.3V
+/- 0.3V
5V
+/- 0.25V
U/V
50
power up
V
DD3
limit
V
DD5
limit
t/ms
N
power down
V
DD3
limit
V
DD5
limit
N+50
0
0.1V
Within the grey boxes any shape of V
and V
signal is allowed with the requirements that the absolute
limits of each signal are not exceeded, the slew rate recommendation for V
DD3
is met to guarantee proper
boundary scan reset and the voltage difference does not exceed 3.6V.
Outside the grey boxes the voltages provided to V
DD3
and V
DD5
should be inside the normal operation range.
In this power-up example V
DD5
is enabled after V
DD3
reached its minimum operation value which is a typical
implementation.
For power-down V
DD5
is switched off before V
DD3
.