5V/3V PC Card Power Switch
General Description
The AAT4650 SmartSwitch is a single channel PC
card (PCMCIA) power switch. It is used to select
between two different voltage inputs, each between
2.7V and 5.5V. An internal switch powers the cir-
cuitry from whichever input voltage is higher. The
device's output, V
CC
, is slew rate controlled and cur-
rent limited, in compliance with PC card specifica-
tions. The current limit response time to a short cir-
cuit is typically 1µs. The internal P-channel MOSFET
switches are configured to break before make; that
is, both switches cannot be closed at the same time.
Controlled by a 2-bit parallel interface, the four states
for V
CC
are V
CC5
, V
CC3
, high impedance, or ground.
When in the ground state, V
CC
is pulled to ground by
a 5kΩ resistor. An open drain FAULT output is
asserted during over-current conditions. During
power-up slewing, FAULT also signals that V
CC
is out
of tolerance. An internal over-temperature sensor
forces V
CC
to a high impedance state when an over-
temperature condition exists. Quiescent current is
typically a low 15µA, as long as I
CC
is less than
approximately 500mA. Above this load current, the
quiescent current increases to 200µA.
The AAT4650 is available in a Pb-free, 8-pin SOP
or TSSOP package and is specified over the -40°C
to +85°C temperature range.
AAT4650
Features
•
•
•
•
•
•
•
•
•
SmartSwitch
™
2.7V to 5.5V Input Voltage Range
80mΩ (5V) Typical R
DS(ON)
Low Quiescent Current 15µA (typ)
Reverse-Blocking Switches
Short-Circuit Protection
Over-Temperature Protection
FAULT Flag Output
Temperature Range: -40°C to +85°C
8-Pin SOP or TSSOP Package
Applications
•
•
•
Notebook Computer
PDA, Subnotebook
Power Supply Multiplexer Circuit
Typical Application
V
CC5
V
CC3
CTL1
CTL0
FAULT
C
IN5
1μF
C
IN3
1μF
8
5
3
2
4
1
VCC5
VCC3
CTL1
AAT4650
VCC
CTL0
FAULT
GND
6,7
V
CC
C
OUT
0.1μF
GND
GND
4650.2006.05.1.2
1
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
