AOZ1300

AOZ1300
Programmable 4A Power Distribution Switch
General Description
Features
The AOZ1300 is a current-limited power distribution
switch intended for applications that require circuit
protection. The device operates from a 2.7V to 6.0V
input supply and provides up to 4A load current.
AOZ1300 offers robust fault protection features including
over-current/short-circuit protection and thermal overload
protection. The current limit is programmable with an
external resistor. An open-drain fault indicator is provided
to alert a system controller of thermal overload, overcurrent, and short-circuit events. A 24ms fault blanking
time eliminates false alarms.
●
40mΩ maximum on-resistance
●
4A maximum continuous current
●
2.7V to 6.0V operating voltage
●
Resistor programmable current limit
●
Reverse current blocking
●
Thermal overload protection
●
Very fast short-circuit response time
●
Fault latch with 24ms blanking time
●
Open-drain fault indicator
The AOZ1300 employs internal soft-start circuitry to
control inrush current due to highly capacitive loads
associated with hot-plug events. An adjustable slew rate
control pin provides additional slew rate control if
needed.
●
1µA shutdown current
●
UL Listed – File No. E326264
●
Docking stations
The AOZ1300 is available in SO-8 package.
●
Notebook PCs
●
RAID systems
●
Telecom and Server hot-plug
●
USB Power Distribution
●
Compact PCI adapter Cards
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Typical Application
VOUT
VIN
IN
C1
1μF
OUT
C2
4.7μF
R1
100kΩ
TO USB
PORT
AOZ1300
FLT
FAULT
OFF ON
GND
EN
SLEW
C3
10nF
ISET
R2
70kΩ
Figure 1. High Current USB Host
Rev. 1.8 April 2010
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Page 1 of 12
AOZ1300
Ordering Information
Part Number
Temperature Range
Package
Environmental
AOZ1300AI
-40°C to +85°C
SO-8
RoHS Compliant
AOZ1300AIL
-40°C to +85°C
SO-8
Green Product
AOS Green Products use reduced levels of Halogens, and are also RoHS compliant.
Please visit www.aosmd.com/web/quality/rohs_compliant.jsp for additional information.
Pin Configuration
IN
1
8
OUT
SLEW
2
7
IC
GND
3
6
FLT
ISET
4
5
EN
SO-8
(Top View)
Pin Description
Pin Number
Pin Name
Pin Function
1
IN
Switch Power Input. IN also supplies power to internal circuitry.
2
SLEW
Slew Rate Control Pin. Leaving this pin open results in a minimum output slew rate.
Connect a capacitor from SLEW to GND to increase output slew rate.
3
GND
Ground.
4
ISET
Current-Limit Setting Pin. Connect a resistor from ISET to GND to set the currentlimit.
5
EN
Enable Input. Pull EN high to enable the device. The part enters into low-power
shutdown when EN is pulled low.
6
FLT
Fault Indicator. FLT is an open-drain output. FLT is asserted low during over-current
or thermal overload events. FLT is asserted after the fault blanking period.
7
IC
Internally Connected Pin. No external connection is allowed to this pin. Leave this
pin floating.
8
OUT
Switch Output Pin.
Rev. 1.8 April 2010
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Page 2 of 12
AOZ1300
Absolute Maximum Ratings
Recommend Operating Ratings
Exceeding the Absolute Maximum ratings may damage the
device.
The device is not guaranteed to operate beyond the Maximum
Operating Ratings.
Parameter
IN, OUT, EN, FLT, ISET, SLEW to GND
Rating
Parameter
Rating
6.5V
Input Supply Voltage (VIN)
+2.7V to +6.0V
OUT Maximum Continuous Current
5A
Junction Temperature (TJ)
-40°C to +125°C
Junction Temperature (TJ)
+150°C
SO-8 Thermal Resistance (ΘJA)(1)
87°C/W
Storage Temperature (TS)
-65°C to +150°C
Note:
1.The package ΘJA is measured with the device mounted on 1-in2 FR-4
printed circuit board with 2oz. Copper, in a still air environment with
TA = 25°C. The value may vary depending on the user’s specific
board design.
Electrical Characteristics
VIN = 5V, TA = 25°C unless otherwise stated.
Symbol
Parameter
Conditions
VIN
Supply Voltage
IIN
Supply Current
Switch on, no load
Switch off, no load
VUV
Undervoltage Lockout Threshold
VIN rising
VUVHYS
Undervoltage Lockout Hysteresis
VEN
VENHYS
Enable Input Voltage
Min.
Typ.
Max.
Units
6.0
V
380
1
530
2
µA
2.3
2.68
V
2.7
1.9
300
Enable Input Low Voltage
Enable Input High Voltage
mV
0.8
Enable Input Voltage Hysteresis
400
IEN
Enable Input Current
VIN = 4.5V
RDS(ON)
Switch On Resistance
VIN = 4.5V
VIN = 2.5V
ILIM
Current Limit
RSET =76.8kΩ, TA = +25°C to +85°C
IOFF
Output Leakage Current
VOL
FLT Output Voltage
tFLT
FLT Timeout Period
ILIM to FLT assertion,
TA = +25°C to +85°C
tON
Output Turn-on Delay
RL = 10Ω, CL = 1µF
tOFF
V
2.0
mV
1
µA
35
48
45
60
mΩ
4.0
4.8
A
Switch Off
1
µA
IOL = 5mA
0.4
V
3.2
FLT Output Leakage Current
18
24
750
1
µA
30
ms
µs
Output Turn-off Delay
RL = 10Ω, CL = 1µF
43
µs
tr
Output Rise-time
RL = 10Ω, CL = 1µF
460
µs
tf
Output Fall-time
RL = 10Ω, CL = 1µF
15
µs
Rev. 1.8 April 2010
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Page 3 of 12
AOZ1300
Typical Performance Characteristics
Supply Current vs. Temperature
Enable Input Threshold (Falling) vs. Temperature
1.60
5.5V
450
1.50
400
1.40
350
1.30
Ven (V)
Supply Current (μA)
500
300
250
3.6V
200
1.10
2.5V
2.5V
-20
0.90
0
20
40
60
Temperature (°C)
80
0.80
-40
100
Enable Input Threshold (Rising) vs. Temperature
2.00
1.90
1.80
1.70
1.60
1.50
1.40
1.30
1.20
1.10
1.00
-20
0
100
3.6V
2.5V
50
40
30
2.5V, 3.6V, 5.5V
20
10
0
-20
0
20
40
60
80
100
-40
-20
0
Temperature (C)
On Resistance (mΩ)
UVLO+
2.25
2.20
2.15
2.10
UVLO-
2.05
100
-20
0
20
40
60
Temperature (°C)
80
60
55
2.5V
50
45
3.6V
40
35
5.5V
30
25
20
100
-40
26
1.40
Turn-On Delay (μS)
1.50
25
3.6V
24
5.0V
5.5V
23
-20
0
20
40
60
Temperature (°C)
80
100
80
100
Turn-On Delay vs. Temperature
Fault Delay vs. Temperature
27
22
21
20
-40
80
65
2.30
2.00
-40
20
40
60
Temperature (C)
On Resistenace vs. Temperature
UVLO Threshold vs. Temperature
2.35
UVLO (V)
80
Output Leakage Current vs. Temperature
5.5V
-40
Fault Delay (ms)
20
40
60
Temperature (°C)
60
Output Leakage (nA)
Ven (V)
3.6V
1.20
1.00
150
100
-40
5.5V
1.30
2.5V
1.20
1.10
3.6V
1.00
0.90
5.5V
0.80
-20
Rev. 1.8 April 2010
0
20
40
60
Temperature (°C)
80
100
0.70
-40
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-20
0
20
40
60
Temperature (°C)
Page 4 of 12
AOZ1300
Turn-On
Turn-Off
EN
5V/div
EN
5V/div
VOUT
2V/div
VOUT
2V/div
I OUT
1A/div
I OUT
1A/div
Time (1ms/div.)
Time (200μs/div.)
Output Slew Rate Control
Short Circuit Response
EN
5V/div
VOUT
5V/div
FLT
5V/div
FLT
5V/div
I OUT
1A/div
VOUT
2V/div
I OUT
1A/div
Time (4ms/div.)
Time (4ms/div.)
Latched Output
UVLO Response
EN
5V/div
VIN
5V/div
FLT
5V/div
VOUT
5V/div
VOUT
5V/div
I OUT
5A/div
Time (4ms/div.)
Rev. 1.8 April 2010
Time (20ms/div.)
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Page 5 of 12
AOZ1300
Timing Diagrams
50%
50%
EN
90%
10%
VOUT
t ON
t OFF
Active-High Enable
ILIM
IOUT
FLT
t FLT
Over-current Fault Output Response
Functional Block Diagram
IN
OUT
Switch
Charge Pump
Gate Driver &
Slew Rate
Control
SLEW
Current Limit
ISET
2.3V
UVLO
Comparator
Thermal
Shutdown
EN
FLT
Fault Delay &
Latch
Rev. 1.8 April 2010
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Page 6 of 12
AOZ1300
Detailed Description
The AOZ1300 is a high-side, current-limited, N-channel
MOSFET switch optimized for power distribution
applications which require circuit protection. The device
operates from 2.7V to 6.0V input voltage and offers
current limiting and thermal overload protection. The
device can be programmed for load current up to 4A
using a single resistor. An open-drain fault output is
provided to indicate over-current and thermal overload
fault conditions. The AOZ1300’s soft-start circuitry
minimizes the inrush current in applications that employ
highly capacitive loads. The output slew-rate may be
increased with an external capacitor if longer soft-start
time is desired. The AOZ1300 features a circuit breaker
mode that latches the output off upon detecting an overcurrent condition lasting more than 24ms or detecting a
thermal overload condition. The AOZ1300 features
reverse current blocking function. Therefore, the output
voltage can be higher than the input voltage.
Enable
The EN pin is the ON/OFF control for the output switch.
It is an active-high input. The EN pin is active after VIN is
above the UVLO threshold of 2.3V. Conversely, the
Enable will be de-activated if the VIN falls below the
UVLO of 2.0V. The EN pin must be driven to a logic high
or logic low state to guarantee operation. While disabled,
the AOZ1300 only draws about 1µA supply current. The
EN is a high impedance input with an ESD protection
diode to ground and should not be forced below ground.
This input level is compatible with most microcontroller
outputs and other logic families.
Under-Voltage Lockout (UVLO)
The under-voltage lockout (UVLO) circuit of AOZ1300
monitors the input voltage and prevents the output
MOSFET from turning on until VIN exceeds 2.3V. The
AOZ1300 will trigger a fault condition and shut down
the device when VIN falls below 2.0V.
Over-Current and Short-Circuit Protection
The AOZ1300 is designed to shut off all power to the
load when the output current exceeds the limit for more
than the fault blanking period. In the event of an output
short circuit the current through the switch is limited by an
internal current-limiting amplifier. The current-limit circuit
employs a current- sensing algorithm that uses the
on-state resistance of the high-side MOSFET as a
current-sensing element. If the current-sense voltage is
above the current-limit threshold, the AOZ1300 will turn
off the internal MOSFET. The AOZ1300 has a very fast
short-circuit response time, nominally 25µs. Once the
Rev. 1.8 April 2010
output shuts off, it remains off until the fault load is
removed from output and the EN input is toggled or the
input power is recycled. If the fault is still present after EN
has been cycled, the AOZ1300 will again shut off all
power to the load after 24ms.
Thermal Overload Protection
The thermal overload protection of AOZ1300 is engaged
to protect the device from damage should the die
temperature exceeds safe margins due to a short circuit,
extreme loading or heating from external sources.
Thermal overload protection sets a fault latch and shuts
off the internal MOSFET and asserts the FLT output if the
junction temperature exceeds +120°C. The AOZ1300
can be re-enabled by toggling EN pin or cycling the input
supply after the die temperature drops below +110°C.
Fault Indicator
The FLT pin is an open drain output that is asserted low
when either an over-current, short-circuit or thermal
overload condition occurs. To prevent false alarm, the
AOZ1300 implements a 24ms fault blanking time for
over-current and short-circuit fault conditions. The FLT
pin becomes high impedance when the fault conditions
are removed. A 100kΩ pull-up resistor must be
connected between FLT to VIN to provide a logic signal.
Slew Rate Control
The output voltage rise time is controlled to a minimum of
400µs and is controlled by an internal slew-rate limiting
circuit. The slew-rate can be increased by placing a
capacitor between SLEW and ground. As a result, longer
rise times can be achieved for specific applications. The
slew rate is independent from the load. Please see Slew
Rate Setting section for detailed information.
Applications Information
Input and Output Capacitor Selection
The input capacitor prevents large voltage transients
from appearing at the input, and provides the instantaneous current needed each time the switch turns on
and to limit input voltage drop. Also it is to prevent
high-frequency noise on the power line from passing
through the output of the power side. The choice of the
input capacitor is based on its ripple current and voltage
ratings rather than its capacitor value. The input capacitor should be a low ESR type and located as close to the
VIN pin as possible. A 0.1µF 6.3V ceramic cap is
recommended. However, higher capacitor values further
reduce the voltage drop at the input.
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Page 7 of 12
AOZ1300
Current Limit Setting
The output capacitor acts in a similar way. A small 0.1µF
capacitor prevents high-frequency noise from going into
the system. Also, the output capacitor has to supply
enough current for a large load that it may encounter
during system transients. This bulk capacitor must be
large enough to supply fast transient load in order to
prevent the output from dropping.
The AOZ1300 features internal current-limiting circuitry
with a maximum programmable value of 4.5A. This
current limit remains in effect throughout the input
supply-voltage range. The current limit is program by
using external resistor connected to the ISET pin. The
current-limit adjustment resistor range is from 60kΩ to
600kΩ.
Current Limit vs. Rset @ 3.6V
600
500
500
400
400
Rset (kΩ)
Rset (kΩ)
Current Limit vs. Rset @ 5.5V
600
300
300
200
200
100
100
0
0.5
1.0
1.5
2.0
2.5
3.0
Current Limit (A)
3.5
4.0
0
0.5
4.5
1.0
1.5
2.0
2.5
3.0
Current Limit (A)
4.0
4.5
3.5
4.0
4.5
Current Limit vs. Rset @ 2.7V
600
Rset (kΩ)
500
400
300
200
100
0
0.5
1.0
1.5
2.0
2.5
3.0
Current Limit (A)
Slew Rate Setting
Slew rate is set by changing the capacitor value on the
Slew pin of the device. A capacitor connected between
this pin and ground will reduce the output slew-rate. The
3.5
capacitor requires a 6.3V rating or greater. The capacitive range is 0.001µF to 0.1µF. Please see graph for Output Slew Rate Adjustment vs. Capacitance.
4.00
70.000
3.50
60.000
3.00
5.5V
50.000
3.6V
40.000
2.5V
30.000
20.000
Output Slew Rate Adjustment
5.5V
2.50
3.6V
2.00
1.50
2.5V
1.00
0.50
10.000
0.000
0
Slew Rate (mS)
Slew Rate (mS)
Output Slew Rate Adjustment
80.000
0.00
0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
Capacitance (μF)
Rev. 1.8 April 2010
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0
1
2
3
Capacitance (nF)
4
5
Page 8 of 12
AOZ1300
Power Dissipation Calculation
Calculate the power dissipation for normal load condition
using the following equation:
PD = RON x (IOUT)2
The worst case power dissipation occurs when the load
current hits the current limit due to over-current or short
circuit faults. The power dissipation under these conditions can be calculated using the following equation:
PD = (VIN – VOUT) x ILIMIT
PCB Layout Guidelines
Proximity of passive devices and adequate power and
ground planes are critical for reliable operation of the
circuit. In general, use the top layer for the high current
connections and the bottom or inner layer for the quiet
connections such as GND. The power traces must be
as short and wide as possible, because of large current.
Long metal traces and component leads may cause
unwanted parasitic inductance and capacitance. In order
to achieve the best performance special care has to be
taken for proper grounding. A good practice is always the
use of a separate ground plane or at least a single point
ground structure. It is recommended to use a PCB with at
least two sides. It is very important to place the input and
output capacitor as close as possible to the pin of the
device.
Silk Screen Top
Top Layer
Bottom Layer
Rev. 1.8 April 2010
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Page 9 of 12
AOZ1300
Package Dimensions, SO-8L
D
Gauge Plane
Seating Plane
e
0.25
8
L
E
E1
h x 45°
1
C
θ
7° (4x)
A2 A
0.1
b
A1
Dimensions in millimeters
2.20
5.74
1.27
0.80
Unit: mm
Symbols
A
A1
A2
b
Min.
1.35
0.10
1.25
0.31
c
D
E1
0.17
4.80
3.80
e
E
5.80
h
L
θ
0.25
0.40
0°
Nom.
1.65
—
1.50
Max.
1.75
0.25
1.65
—
—
4.90
0.51
0.25
5.00
3.90
4.00
1.27 BSC
6.00
—
—
6.20
0.50
1.27
—
8°
Dimensions in inches
Symbols
A
A1
A2
b
Min.
0.053
0.004
0.049
0.012
Nom.
0.065
—
0.059
—
Max.
0.069
0.010
0.065
0.020
c
D
E1
0.007
0.189
0.150
—
0.193
0.154
0.010
0.197
0.157
e
E
0.228
h
L
θ
0.010
0.016
0°
0.050 BSC
0.236 0.244
—
—
—
0.020
0.050
8°
Notes:
1. All dimensions are in millimeters.
2. Dimensions are inclusive of plating
3. Package body sizes exclude mold flash and gate burrs. Mold flash at the non-lead sides should be less than 6 mils.
4. Dimension L is measured in gauge plane.
5. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact.
Rev. 1.8 April 2010
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Page 10 of 12
AOZ1300
Tape and Reel Dimensions, SO-8L
SO-8 Carrier Tape
P1
D1
See Note 3
P2
T
See Note 5
E1
E2
E
See Note 3
B0
K0
A0
D0
P0
Feeding Direction
Unit: mm
Package
SO-8
(12mm)
A0
6.40
±0.10
B0
5.20
±0.10
K0
2.10
±0.10
D0
1.60
±0.10
D1
1.50
±0.10
E
12.00
±0.10
SO-8 Reel
E1
1.75
±0.10
E2
5.50
±0.10
P0
8.00
±0.10
P1
4.00
±0.10
P2
2.00
±0.10
T
0.25
±0.10
W1
S
G
N
M
K
V
R
H
W
N
Tape Size Reel Size
M
W
12mm
ø330
ø330.00 ø97.00 13.00
±0.50
±0.10 ±0.30
W1
17.40
±1.00
H
K
ø13.00
10.60
+0.50/-0.20
S
2.00
±0.50
G
—
R
—
V
—
SO-8 Tape
Leader/Trailer
& Orientation
Trailer Tape
300mm min. or
75 empty pockets
Rev. 1.8 April 2010
Components Tape
Orientation in Pocket
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Leader Tape
500mm min. or
125 empty pockets
Page 11 of 12
AOZ1300
Package Marking
Z1300AI
Part Number Code
Underscore Denotes Green Product
FAYWLT
Assembly Lot Code
Fab & Assembly Location
Year & Week Code
Rev. 1.8 April 2010
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Page 12 of 12