sp2525-2en Exar Corporation, sp2525-2en Datasheet - Page 4

• Manufacturer Part Number: sp2525-2en
• Description: 3.0v To 5.5v Usb Power Control Switch
• Manufacturer: Exar Corporation

FEATURES
The SP2525 device is a single +3.0V to +5.5V
USB Supervisory Power Control Switch ideal
for self-powered and bus-powered Universal
Serial Bus (USB) applications. USB provides
a +5.0V bus and ground return line in addition
to a twisted pair line for data.
Features of the SP2525 device include current
limiting, a +2.7V undervoltage lockout, over-
temperature shutdown, error flag output, soft
start power up, a switch-on resistance of 140m
over the entire supply range, and a supply
current of 80 A. The SP2525-1 device has
active-high inputs. The SP2525-2 device has
active-low inputs.
THEORY OF OPERATION
There are operational conditions that will en-
able or disable one or more of the output
transistors, depending on the type of hazard.
Certain conditions will activate the open-drain
error flag transistors forcing the flag output to
ground. The SP2525 device is a single inte-
grated high-side power switch optimized for
self-powered and bus-powered Universal Se-
rial Bus (USB) applications. The SP2525 de-
vice provides the following functions:
1) Solid State Switch : MOSFET M1 connects
the IN pin to the OUT pins when enabled by a
logic signal at the EN pin.
2) Fault Flag Conditions : The FLG pin is an
N-channel, open-drain MOSFET output ca-
pable of sinking a 10mA load to typically
100mV above ground.
3) Undervoltage Lockout : The lockout mecha-
nism monitors the input voltage and will enable
the MOSFET switch only when the input sig-
nal is >2.7V.
4) Current Limiting Threshold : A current
limiting threshold is set internally to prevent
any damage to the device and external load.
Rev. 8/21/01
SP2525 +3.0 to +5.5 Power Control Switch
4
5) Thermal Shutdown : This mechanism pro-
tects the device switch and signals a fault condi-
tion if the die temperature exceeds 135
function has 10
MOSFET switches from turning on until the die
temperature drops to 125
Input and Output
The independent solid state switch connects the
IN pin to the OUT pin when enabled by a logic
signal at EN. The IN pin is the power supply
connection to the internal circuitry and the drain
of the output MOSFET. The OUT pin is the
source of the MOSFET.
Typically, the current in USB application will
flow through the switch from IN to OUT towards
the load. If V
is enabled, the current will flow from OUT to the
IN pin because the MOSFET channels are bidi-
rectional when switched on.
Under normal operating conditions, the MOSFET
switch will present 140m maximum resistance
when closed. The device is designed to allow
out pin to be externally forced to a higher voltage
than the IN pin when the switch is off.
Fault Flag Conditions
The fault flag is an N-channel, open drain
MOSFET output. The active low fault flag is
asserted when one of the following conditions
exist:
Undervoltage Lockout
This voltage lockout mechanism prevents the
output MOSFET switches from turning on until
V
After the switch turns on, if the voltage at V
drops below +2.5V, the lockout circuitry shuts
off the output MOSFET switch and signals the
FLG fault flag. In the undervoltage lockout
state, the FLG pin will be at a logic low. This
detection functions only when the MOSFET
switch is enabled.
IN
is >2.7V.
1. Undervoltage
2. Soft Start
3. Overcurrent
4. Overtemperature
OUT
O
C of hysteresis that prevents the
is greater than V
© Copyright 2001 Sipex Corporation
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