AAT4672 Datasheet, PDF (1/24 Pages) Advanced Analogic Technologies – Power Supply Selector Switch

SmartSwitch^TM
General Description
The AAT4672 SmartSwitch™ is a member of AnalogicTech’s
Application Specific Power Management IC™ family. This
device is a dual input, single output power supply selec-
tor switch, designed to operate from USB ports, AC
adapter inputs, batteries, or any other power supply with
an input voltage up to 6V.
The AAT4672 connects the supply on the MAIN pin to the
OUT pin through a very low on-resistance power MOSFET
when the device is enabled, the MAIN pin voltage is
higher than the under voltage lockout (UVLO) threshold,
and MAIN pin voltage is greater than the AUX pin voltage
plus 200mV. The AUX pin connects to the OUT pin only
when the MAIN pin voltage drops 0.2V below the AUX pin
voltage and the AUX pin voltage is greater than the
UVLO threshold. If both input supplies (MAIN/AUX) are
below the UVLO threshold, then the OUT pin floats.
The two internal power switches are current limited and
the thresholds can be programmed through resistors on
the IMAIN and IAUX pins respectively. A power level
selection pin, PWRSEL, is provided to toggle the AUX
current limit between 100% and 20% of the current limit
setting programmed by the resistor on the IAUX pin. This
is particularly useful for USB applications where the
power supply can be powered by either a 500mA or a
100mA USB port.
The AAT4672 is available in a thermally enhanced,
space-saving, Pb-free 12-pin TSOPJW package and is
specified for operation over the -40°C to +85°C tem-
perature range.
Typical Application
PRODUCT DATASHEET
AAT4672
Power Supply Selector Switch
Features
• Input Voltage Supply Range: 2.5V to 6V
• High Level of Integration:
▪ Reverse Blocking Diode
▪ Current Sensing
▪ Programmable Current Limiting
▪ Automatic Power Supply Switching
• Break-Before-Make Switch-Over
▪ Minimum Output Voltage Drop During Change-Over
• Shutdown Current < 1µA
• Thermal Protection
• TSOPJW-12 Package
Applications
• Bluetooth™ Headsets
• Cell Phones
• Digital Still Cameras
• MP3 Players
• Personal Data Assistants (PDAs)
AC Adapter
USB Port
USB H/L select
Enable
MAIN
AUX
PWRSEL
EN
OUT
IMAIN
IAUX
GND
System Load
R_IAUX
R_IMAIN
4672.2008.04.1.0
www.analogictech.com
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