AAT4626

USB Dual-Channel Power Switch

10

4626.2006.05.1.2

Hot-Plug Applications

Application circuit cards with a high inrush current

potential can be limited by use of the AAT4626.

The AAT4626 has both slew rate limited turn on

characteristics and current limit controlled outputs,

which make it ideally suited for power port hot-plug

applications. A host power back plane or hot-plug

receptacle may be sensitive to short duration, high

power surges. The AAT4626 will turn on in a linear

ramping fashion and regulate the inrush current

within the specified current limit for the device. The

error flag usually will not be affected during appli-

cation turn-on since the 10ms fault flag blanking

time is intended for these types of events. If an

application turn-on current surge exceeds 10ms,

an RC delay filter may be added to the flag output

to prevent the system from receiving an error dur-

ing the start-up sequence.

Figure 1: Fault Flag Delay RC Filter.

R1

10k

Ω

100k

Ω

C1

0.1

μF

AAT4626

1

2

3

45

6

7

8

ENA

FLGA

FLGB

ENB OUTB

GND

IN

OUTA

V+

USB Controller

Over-Current

Flag Input

Figure 2: AAT4626 Input Inrush Current Protected Dual Output Application.

4.7

μF

AAT4626

1

2

3

45

6

7

8

ENA

FLGA

FLGB

ENB

OUTB

GND

IN

OUTA

(120

μF)

Card

Application

Circuit A

V+

GND

Dual Channel

Inrush Current Protected

Application Card

Cable / Connector

to Hot-Plug Port

GND

Hot-Plug

Receptacle

Card

Application

Circuit B

(120

μF)

0.1

μF