SP619 Datasheet, PDF (4/7 Pages) Sipex Corporation – High Current Power Switch

The SP619 is a switch capable of handling
up to 800mA of current. 7V capability al-
lows the user to have a wide input voltage
range that covers the typical Lithium bat-
tery range as well as higher 5V input volt-
age rails commonly found in USB power.
The SP619 also can be used as a 3V or 5V
power distribution switch. It is intended for
power distribution applications where short
circuits are likely to be encountered.
Short circuit operation
When the SP619 enters a short circuit con-
dition, the switch is disabled. The output
of the SP619 will not restart until the out-
put impedance is greater than 15KΩ. The
enable pin can be used to re-enable the
SP619 into any load condition that is not
a fault condition. Refer to the truth table on
page 4 for more information on the differ-
ent SP619 switch states. The typical deac-
tivation time is about 2ms.
Enable
The enable pin allows easy control of the
SP619. The enable pin should not be en-
abled high prior to a voltage being pres-
ent on the input of the device. The enable
pin should not exceed the input voltage by
more than 0.1V due to an internal ESD di-
ode. Doing so will affect the operation of
the SP619 and could damage the device.
In a typical application an 80KΩ resistor to
GND should be used on the enable pin.
This resistor will pull the enable low when
an enable signal is not present. This pre-
vents the SP619 from falsely turning on.
The enable pin can also be used to restart
the part into a load condition that is high in
current. Please refer to the truth table on
page 4 for more details.
Inrush Current
The SP619 is a simple resistive switch.
When the switch is turned on into a highly
capacitive load there could be a significant
THEORY OF OPERATION
inrush current that can be encountered.
At 6 volts in, the inrush current was about
250mA into a 100µF capacitor.
Output Voltage Rise Time
The output voltage of the SP619 has an
output capacitance dependency on the
slope of Vout. A simple RC circuit is cre-
ated when the switch is turned on.
Equation 1
( ^V(t)=Vo+Vin
-t
1-e^{Rds(on) • Cout}
Where Vo is initial Voltage condition typi-
cally 0V
Vin is the input voltage
Rds(on) is the switch resistance
Cout is the output capacitance
For 4.2V Vin and 100µF output capacitance
we get about 150ns delay in figure 2.
4.17
3.33
VOUT 2.5
1.67
0.83
0
0
0.33
0.67
1
1.33
1.67
2
time in uS
This is comparable to actual measured
value in figure 3.
Jul23-07 Rev K
SP619 High Current Power Switch

© 2007 Sipex Corporation