88PG8226A1-NFE1C000 Marvell, 88PG8226A1-NFE1C000 Datasheet - Page 20

• Manufacturer Part Number: 88PG8226A1-NFE1C000
• Manufacturer: Marvell

V
V
OUT1
OUT2
V
EN
Figure 4: Output Voltage Window
3.1.1
Doc. No. MV-S103563-00 Rev. C
Page 20
Figure 5: Startup without
Typical V
Sequencing
1.0 ms/DIV
Soft Start and Sequencing
The 88PG82XX device’s outputs can either be sequenced to start up together or have V
followed by V
up time in the order of 100 μs, as shown in
and V
will have a soft start ramp. The POR2 output will go high 40 ms after V
limits.
Soft start is a highly desirable property in “Hot-Plug” applications. The 88PG82XX starts up in less
then 100 μs when soft-start is disabled
controls the rise time of the output voltage, thereby dramatically reducing the inrush current. The
88PG82XX rise time is roughly 0.25V/ms and it is independent of output capacitance and load
current (see
Although there is a difference in output capacitance between
voltage rise time difference is less than 0.1 ms.
OUT
88PG82XX
Datasheet
OUT2
will start as soon as V
Figure
OUT2.
When the SDI pin is low, the V
8).
Document Classification: Proprietary Information
Figure 9
2V/DIV
1V/DIV
1V/DIV
shows the output voltage rise time with a 100 μF output capacitor.
OUT1
is within its specified tolerance (see
A
B
C
D
(Figure
V
V
OUT2
OUT1
V
Figure
IN
7). However in soft-start mode, the 88PG82XX
Figure 6: Startup with Sequencing
OUT1
5. If the SDI pin is high, then V
and V
Figure 6
OUT2
and Soft Start (C
2.0
will start up together with a start
and
m
OUT2
s/DIV
Figure
Figure
PFM Mode
PWM Mode
PFM Mode
is within its regulation
Copyright © 2008 Marvell
OUT1
OUT
9, the output
6). Both outputs
April 23, 2008, 2.00
= 22
will start first
OUT1
μ
F)
start
5V/DIV
1.0V/DIV
1V/DIV