AAT4650_06 ANALOGICTECH [Advanced Analogic Technologies], AAT4650_06 Datasheet - Page 7

• Manufacturer Part Number: AAT4650_06
• Description: 5V/3V PC Card Power Switch
• Manufacturer: ANALOGICTECH [Advanced Analogic Technologies]

Functional Description
The AAT4650 is a single channel power switch that
can be used in any application where dual power
supply multiplexing is required. Typical applications
include PC card applications not requiring a 12V
power supply, or applications where power is
switched, for example, between 5V for operation
and 3.3V for standby mode. The AAT4650 operates
with input voltages ranging from 2.7V to 5.5V in any
combination and automatically powers its internal
circuitry off of whichever input voltage is higher. Two
identical low R
the power multiplexing circuit with a common drain
as the V
two V
determines the state of the multiplexer: V
V
or V
either of the two inputs, the multiplexing circuit will
Functional Block Diagram
4650.2006.05.1.2
CC
CC
= V
CC3
high impedance. When the state is set to
CC5
CC
and V
, V
output and independent sources as the
CC
DS(ON)
CC5
with resistive pull down to ground,
CTL1
CTL0
inputs. A 2-bit parallel interface
P-channel MOSFETs serve as
Temperature
Over-
Control
Logic
CC
Current
= V
Over-
Slew
Rate
CC3
V
CC3
,
Body Control
slowly slew the V
which protects the upstream power supply from sud-
den load transients. When the resistive pull down is
chosen for V
by the resistive pull down. The AAT4650 always
serves as an electronic fuse by limiting the load cur-
rent if it exceeds the current limit threshold. During
power-up into a short, the current will gradually
increase until the current limit is reached. During a
sudden short circuit on the output, the current limit
will respond in 1µs to isolate and protect the
upstream power supply from the load short circuit.
In most applications, because the response time is
so fast, a short circuit to V
upstream supply, so system functionality will not be
affected. In the case of an over-current condition,
an open drain FAULT flag output will signal the
event. The FAULT output is also active during out-
put voltage slew, and becomes inactive once the
output is within regulation.
V
CC5
Current
Over-
Slew
Rate
5V/3V PC Card Power Switch
CC
, the V
GND
CC
5kΩ
output to the new voltage level
CC
output is quickly discharged
FAULT
V
CC
CC
will not affect the
AAT4650
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