AP2145/AP2155

0.5A SINGLE CHANNEL CURRENT-LIMITED POWER

SWITCH WITH OUTPUT DISCHARGE

AP2145/AP2155

Document number: DS32031 Rev. 2 - 2

10 of 13

www.diodes.com

September 2010

© Diodes Incorporated

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.

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

Device

Package

Code

Packaging

(Note 5)

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

Notes:

5. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at

http://www.diodes.com/datasheets/ap02001.pdf.