Product is End of Life 12/2014
SiP4610A/B
Vishay Siliconix
Protected 1-A High-Side Load Switch
APPLICATIONS
•
Peripheral Ports
• Hot Swap
• Notebook Computers
•
PDAs
FEATURES
• 1 A Continuous Output Current
• 2.4 V to 5.5 V Supply Voltage Range
• User Settable Current Limit Level
• Low Quiescent Current
• Undervoltage Lockout
• Thermal Shutdown Protection
• Compatible with AAT4610A
• 4 kV ESD Rating-HBM
DESCRIPTION
SiP4610A/B is a protected highside power switch. It is
designed to operate from voltages ranging from 2.4 V to
5.5 V and handle a continuous current of 1 A. The user
settable current limit protects the input supply voltage from
excessive load currents that might cause a system failure.
SiP4610A/B has a low quiescent current of 9 µA and in
shutdown the supply current is reduced to less than 1 µA.
In addition to current limit, the SiP4610A/B is protected by
undervoltage lockout and thermal shutdown.
There are two versions of the SiP4610. The SiP4610A has
an active low enable input, while the SiP4610B has an active
high enable input.
The SiP4610A/B is available in a lead (Pb)-free 5-pin thin
SOT-23 package for operation over the industrial
temperature range of - 40 to 85 °C.
TYPICAL APPLICATION DIAGRAM
2.4 to 5.5
V
C
IN
Enable
IN
OUT
C
OUT
Load
SiP4610A/B
ON/ON
GND
R
SET
SET
GND
GND
Document Number: 73233
S-71061–Rev. J, 21-May-07
www.vishay.com
1
SiP4610A/B
Vishay Siliconix
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND = 0 V)
Parameter
V
IN
, V
ON
, V
ON
I
MAX
Storage Temperature
Operating Junction Temperature
Power Dissipation
a
, SOT-23 5-Pin
Thermal Impedance (Θ
JA
)
b,
SOT-23 5-Pin
Notes:
a. Derate 5.5 mW/°C above T
A
= 70 °C.
b. Device mounted with all leads soldered or welded to PC board.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation
of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.
Limit
- 0.3 to 6
2
- 65 to 150
- 40 to 150
305
180
Unit
V
A
°C
°C
mW
°C/W
RECOMMENDED OPERATING RANGE
(All voltages referenced to GND = 0 V)
Parameter
IN
Operating Temperature Range
Limit
2.4 to 5.5
- 40 to 85
Unit
V
°C
SPECIFICATIONS
a
Test Conditions Unless Specified
Parameter
Power Supplies
Supply Voltage
Quiescent Current
Shutdown Current
Switch Off Current
Enable Inputs
ON/ON High
ON/ON Low
ON/ON Leakage Current
Turn Off Time
Turn On Time
Output
On-Resistance
Current Limit
Minimum Current Limit
Current Limit Response Time
Undervoltage Lockout
UVLO Threshold
UVLO Hysteresis
Thermal Shutdown
Thermal Shutdown Threshold
Hysteresis
T
T
HYST
20
165
°C
V
UVLO
V
HYST
Rising Edge
1.8
0.05
2.4
V
r
DS
I
L
I
L(min)
t
RESP
IN = 5 V
IN = 5 V, T
A
= 25 °C
IN = 3 V, T
A
= 25 °C
R
SET
= 6.8 kΩ
0.75
145
190
1
130
4
180
230
1.25
mΩ
A
mA
µs
V
IH
V
IL
I
LH
t
OFF
t
ON
IN = 2.4 V to 5.5 V
ON/ON = 5 V
IN = 5 V, R
L
= 10
Ω
11
65
2.0
0.8
1
21
200
µA
µs
V
V
IN
I
Q
I
SD
I
S(off)
IN = 5 V, ON/ON = Active, l
OUT
= 0 A
IN = 5 V, ON/ON = Inactive
IN = 5 V, ON/ON = Inactive, V
OUT
= 0 V
2.4
9
5.5
25
1
1
µA
V
Symbol
IN = 5 V, T
A
= - 40 to 85 °C
Min
a
Limits
Typ
b
Max
a
Unit
Notes:
a. The algebraic convention whereby the most negative value is a minimum and the most positive a maximum ( - 40 to 85 °C).
b. Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing.
c. Guaranteed by design.
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2
Document Number: 73233
S-71061–Rev. J, 21-May-07
SiP4610A/B
Vishay Siliconix
DETAILED DESCRIPTION
The SiP4610 limits load current by sampling the pass
transistor current and passing that through an external
resistor, R
SET
. The voltage across R
SET
, V
SET
, is then
compared with an internal reference voltage, V
REF
. In the
event that load current surpasses the set limit current, V
SET
will exceed V
REF
causing the pass transistor gate voltage to
increase, thereby reducing the gate to source voltage of the
PMOS switch and regulating its current back down to I
LIMIT
.
P = I
LOAD
x (V
IN
- V
OUT
)
Once this exceeds the maximum power dissipation of the
package, the die temperature will rise. When the die
temperature exceeds an over-temperature limit of 165 °C,
the SiP4610 will shut down until it has cooled down to 145
°C, before starting up again. As can be seen in the figure
below, the SiP4610 will continue to cycle on and off until the
load is reduced or the part is turned off (See Figure 2).
The maximum power dissipation in any application is
dependant on the maximum junction temperature, T
J(MAX)
=
125 °C, the junction-to-ambient thermal resistance for the
SOT23-5 package,
θ
J-A
= 180 °C/W, and the ambient
temperature, T
A
, which may be formulaically expressed as:
Setting the Current Limit Level
Setting the current limit level on the SiP4610 requires some
care to ensure the maximum current required by the load will
not trigger the current limit circuitry. The minimum current
limit threshold should be determined by taking the maximum
current required by the load, I
LOAD
, and adding 25 %
headroom. The SiP4610 has a current limit tolerance of
25 %, which is largely a result of process variations from part
to part, and also temperature and V
IN
/V
OUT
variances. Thus,
to ensure that the actual current limit is never below the
desired current limit a 1/0.75 = 1.33 coefficient needs to be
added to the calculations. Knowing the maximum load
current required, the value of R
SET
is calculated as follows.
R
SET
= R
SET
coefficient/I
LIMIT
where I
LIMIT
= (I
LOAD
x 1.33) x 1.25 and R
SET
coefficient is
7100 for a 1 A current limit. For typical R
SET
coefficient
values given a limit current refer to the "Typical
Characteristics" section.
P (max) =
T
J
(max) − T
A
θ
J −A
=
125 − T
A
180
It then follows that assuming an ambient temperature of
70 °C, the maximum power dissipation will be limited to about
305 mW.
Reverse Voltage
The SiP4610 is designed to control current flowing from IN to
OUT. If the voltage on OUT is raised higher than IN current
will flow from OUT to IN but the current limit function will not
be available, as can be inferred from the block diagram in
Figure 1. Thus, in applications were OUT is used to charge
IN, careful considerations must be taken to limit current
through the device and protect it from becoming damaged.
Operation at Current Limit and Thermal Shutdown
In the event that a load higher than I
LIMIT
is demanded of the
SiP4610, the load current will stay fixed at the current limit
established by R
SET
. However, since the required current is
not supplied, the voltage at OUT will drop. The increase in
V
IN
- V
OUT
will cause the chip to dissipate more heat. The
power dissipation for the SiP4610 can be expressed as
R
SET
= 3.32 kΩ
V
OUT
= (1 V/div)
I
OUT
(500 mA/div)
20 ms/div
Figure 2. Current Over load Condition. Load Switch turned on with 0.1
Ω
load at time = 0 ms.
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4
Document Number: 73233
S-71061–Rev. J, 21-May-07
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