SmartSwitch
™
AAT4644
4-Channel Current Limited Load Switch
Preliminary
Information
4644.2002.01.0.92 1
General Description
The AAT4644 is a four-channel resettable fuse. It
utilizes independent current-limited and thermally
protected P-channel MOSFETs to protect against
short circuits. Each switch's current limit is factory
programmed at 1A. Additional protection is provid-
ed with undervoltage lockout; the switches are
turned off when the input voltage drops below a
preset level. The quiescent supply current is typi-
cally 20µA. The AAT4644 is a flexible solution,
allowing system designers to gang outputs togeth-
er for lower R
DS(ON)
and higher current limit.
The AAT4644 is available in 8 pin TSSOPor SOP
packages, specified over -40 to 85°C.
Features
• 500mAper channel steady state
• 4 X 1Acurrent limit trip point
• Over-temp protection
• Fast transient response:
• 1µs (typ) response to short circuit
• 100mΩ typical R
DS(ON)
• Undervoltage Lockout
• Temp range -40 to 85°C
• 8 pin TSSOPor SOPpackages
Applications
• USB ports
• Peripheral ports
• Desktop PCs
Typical Application
AAT4644
2,7 1
3
8
6
4
IN
INPUT
3.3V - 5V
GND
OUT1
OUT2
OUT3
OUT4
OUTPUT1
OUTPUT2
OUTPUT3
OUTPUT4