FPF2174 Fairchild Semiconductor, FPF2174 Datasheet - Page 9

• Manufacturer Part Number: FPF2174
• Description: IC LOAD SWITCH ADVANCED 6MLP 3X3
• Manufacturer: Fairchild Semiconductor
• Series: IntelliMax™r
• Type: High Side Switchr

Specifications of FPF2174

• Number Of Outputs: 1
• Rds (on): 125 mOhm
• Internal Switch(s): Yes
• Current Limit: 200mA
• Voltage - Input: 1.8 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 6-MLP
• Input Voltage: 5.5V
• On / Enable Input Polarity: Active High
• Power Dissipation Pd: 1.4W
• No. Of Outputs: 1
• Internal Switch: No
• Distribution Switch Case Style: MLP
• No. Of Pins: 6
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: FPF2174TR

FPF2174 Rev. F
Description of Operation
The FPF2174 is a current limited switch that protects systems
and loads which can be damaged or disrupted by the
application of high currents. The core of the device is a 0.125
P-channel MOSFET and a controller capable of functioning over
a wide input operating range of 1.8-5.5V paired with a low
forward voltage drop Schottky diode for reverse blocking and a
16V zener diode for output clamp. The controller protects
against system malfunctions through current limiting, under-
voltage lockout and thermal shutdown. The current limit is
preset for 200mA.
On/Off Control
The ON pin controls the state of the switch. Activating ON
continuously holds the switch in the on state so long as there is
no under-voltage on V
150°C. ON is active HI and has a low threshold making it
capable of interfacing with low voltage signals. When the
MOSFET is off, the Schottky diode acts as a barrier so that no
reverse current can flow when V
Fault Reporting
Upon the detection of an over-current, an input under-voltage,
or an over-temperature condition, the FLAGB signals the fault
mode by activating LO. The FLAGB goes LO at the end of the
blanking time and is latched LO and ON must be toggled to
release it. FLAGB is an open-drain MOSFET which requires a
pull-up resistor between V
pull-down on FLAGB is disabled to reduce current draw from
the supply.
Current Limiting
The current limit guarantees that the current through the switch
doesn't exceed a maximum value while not limiting at less than
a minimum value. The minimum current is 200mA and the
maximum current is 400mA. The device has a blanking time of
10ms, nominally, during which the switch will act as a constant
current source. At the end of the blanking time, the switch will
be turned-off and the FLAGB pin will activate to indicate that
current limiting has occurred.
Under-Voltage Lockout
The under-voltage lockout turns-off the switch if the input
voltage drops below the under-voltage lockout threshold. With
the ON pin active the input voltage rising above the under-
voltage lockout threshold will cause a controlled turn-on of the
switch which limits current over-shoots.
IN
or a junction temperature in excess of
IN
and FLAGB. During shutdown, the
OUT
is greater than V
IN
.
9
Thermal Shutdown
The thermal shutdown protects the die from internally or
externally generated excessive temperatures. During an over-
temperature condition the FLAGB is activated and the switch is
turned-off.
temperature of the die drops below the threshold temperature.
Transient Safe Operating Area of Zener Diode
Integrated zener diode is designed to protect systems from a
transient over voltage stress resulting from a flyback voltage
(L*di/dt) such as connecting the output of switch to an active
rails.
When the transient voltage exceed the zener threshold (Vz) the
zener starts conducting and prevents the output of loadswitch
from experiencing those transient over voltages and protects
any reverse current from flowing through the switch. For reliable
operation, user should not exceed the SOA curve shown in
Figure 13.
The
switch
automatically
turns-on
www.fairchildsemi.com
again
if