
MSC7116 Data Sheet, Rev. 13
Hardware Design Considerations
Freescale Semiconductor
46
3.2.2.4
Case 4
The power-up sequence is as follows:
1.
Turn on the VDDIO (3.3 V) supply first.
2.
Turn on the VDDC (1.2 V), VDDM (2.5 V), and VREF (1.25 V) supplies simultaneously (second).
Note:
Make sure that the time interval between the ramp-up of VDDIO and VDDC is less than 10 ms.
The power-down sequence is as follows:
1.
Turn off the VDDC (1.2 V), VREF (1.25 V), and VDDM (2.5 V) supplies simultaneously (first).
2.
Turn of the VDDIO (3.3 V) supply last.
Use the following guidelines:
Make sure that the time interval between the ramp-up or ramp-down time for VDDC and VDDM is less than 10 ms for
power-up and power-down.
Refer to Figure 33 for relative timing for Case 4.
Figure 33. Voltage Sequencing Case 4
Time
V
o
lt
age
Ramp-down
Ramp-up
VDDIO = 3.3 V
VDDM = 2.5 V
VDDC = 1.2 V
VREF = 1.25 V
<10 ms