AAT4650
5V/3V PC Card Power Switch
™
SmartSwitch
General Description
Features
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, VCC, 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 MOS-
FET 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 VCC are VCC5, VCC3, Hi-impedance, or
Ground. When in the ground state, VCC is pulled to
ground by a 5kΩ resistor. An open drain FAULT out-
put is asserted during over-current conditions.
During power up slewing, FAULT also signals that
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2.7V to 5.5V Input voltage range
85mΩ (5V) typical RDS(ON)
Low quiescent current 15µA (typ)
Reverse-blocking switches
Short-circuit protection
Over-temperature protection
FAULT flag output
Temp range -40 to 85°C
8 pin SOP or TSSOP package
Applications
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Notebook Computer
PDA, Subnotebook
Power Supply Multiplexer Circuit
VCC is out of tolerance. An internal over temperature
sensor forces VCC to a high impedance state when
an over-temperature condition exists. Quiescent
current is typically a low 15µA, as long as ICC is less
than approximately 500mA. Above this load current,
the quiescent current increases to 200µA.
The AAT4650 is available in 8-pin SOP and
TSSOP packages specified over -40 to 85°C.
Typical Application
8
VCC5
VCC5
VCC3
5
3
2
4
1
VCC3
CTL1
CTL0
FAULT
GND
6,7
VCC
VCC
CTL1
CTL0
FAULT
AAT4650
CIN5
CIN3
COUT
1µF
1µF
0.1µF
GND
GND
4650.2001.10.0.93
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