Diodes AP2145/ AP2155 - Manual (Page 10)

AP2145/ AP2155
Document number: DS32031 Rev. 3 - 2
10 of 13
www.diodes.com
March 2013
© Diodes Incorporated
AP2145/ AP2155
Application Information
(cont.)
Under-Voltage Lockout (UVLO)
Under-voltage lockout function (UVLO) keeps the internal power switch from being turned on until the power supply has reached at least 1.9V, even
if the switch is enabled. Whenever the input voltage falls below approximately 1.9V, the power switch is quickly turned off. This facilitates the design
of hot-insertion systems where it is not possible to turn off the power switch before input power is removed.
Generic Hot-Plug Applications
In many applications it may be necessary to remove modules or pc boards while the main unit is still operating. These are considered hot-plug
applications. Such implementations require the control of current surges seen by the main power supply and the card being inserted. The most
effective way to control these surges is to limit and slowly ramp the current and voltage being applied to the card, similar to the way in which a
power supply normally turns on. Due to the controlled rise times and fall times of the AP2145/AP2155, these devices can be used to provide a
softer start-up to devices being hot-plugged into a powered system. The UVLO feature of the AP2145/AP2155 also ensures that the switch is off
after the card has been removed, and that the switch is off during the next insertion.
By placing the AP2145/AP2155 between the V
CC
input and the rest of the circuitry, the input power reaches these devices first after insertion. The
typical rise time of the switch is approximately 1ms, providing a slow voltage ramp at the output of the device. This implementation controls system
surge current and provides a hot-plugging mechanism for any device.
Ordering Information
AP 21 X 5 XX G - 13
4 : Active Low
5 : Active High G : Green 13 : Tape & Reel 5 : 1 Channel
Channel Green Package Enable Packing
S : SO-8
MP : MSOP-8EP
Part Number Package Code Packaging
13” Tape and Reel
Quantity Part Number Suffix
AP21X5SG-13 S SO-8 2500/Tape & Reel -13
AP21X5MPG-13 MP MSOP-8EP 2500/Tape & Reel -13
Marking Information
(1) SO-8
AP21X X
( Top view )
YY WW X X
Part Number
Logo
WW : Week : 01~52; 52
YY : Year : 08, 09,10~
G : Green
X : Internal Code
8 7 6 5
1 2 3 4
4 : Active Low
5 : Active High
5 : 1 Channel
represents 52 and 53 week