CARD-PCI/GX Hardware Manual
Rev.A
EPSON
51
5.4.2 Power sequence
(for power supply which is not turned ON/OFF from the software)
Follow the power ON/OFF sequence shown below.
Figure 5.2 Power sequence (for power supply which is not turned ON/OFF from the software)
*1: POFF is not used. (Set it to NC.)
*2: I
3V
is the current of V
CC3V
supplied to SCE8720Cxx.
If V
CCORE
starts up after V
CC3V
, or if V
CCORE
shuts down before V
CC3V
, peak current
such as I
PK
is supplied to V
CC3V
. (typical I
PK
=1.8A)
As a system power supply, it must be designed so that it is not damaged if a peak
current is supplied. For that, the following measures are available.
1) Suppress the peak current from the current control circuit. Voltage drop due to this
measure is acceptable.
2) Increase the current capacity.
*3: Connect V
CCSTB
to V
CC5V
.
0.
33V
0.
33V
t
p2
V
CCCORE
V
CC5V
V
CC3V
POFF(*1)
POWERGOOD
t
p1
t
p3
t
p5
t
p7
t
p8
t
p10
I
3V
(*2)
I
PK
4.
75V
0.
5V
3.
15V
4.
75V
t
p4
t
p6
t
p9
3.
15V
I
PK
V
CCSTB
=V
CC5V
(*3)