AAT4651 Datasheet, PDF (1/14 Pages) Advanced Analogic Technologies – 5V/3V PC Card Power Switch

General Description
The AAT4651 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 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
three states for V_CC are V_CC5, V_CC3, or ground.
When in the ground state, V_CC is pulled to ground by
an 200Ω 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 sen-
sor forces V_CC to a high impedance state when an
over-temperature condition exists. Quiescent cur-
rent 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 AAT4651 is available in a Pb-free, 8-pin SOP
or TSSOP package and is specified over the -40°C
to +85°C temperature range.
AAT4651
5V/3V PC Card Power Switch
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
VCC5
VCC3
C_IN5
1μF
GND
VCCD1
VCCD0
FAULT
C_IN3
1μF
8 _VCC5
5 _VCC3
2 _VCCD1
3 _VCCD0
4 _FAULT
1 _GND
AAT4651 ^{VCC 6,7}
C_OUT
0.1μF
VCC
GND
4651.2006.05.1.2
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