AAT AAT4618IJS-0.5-T1 Current limited load switch Datasheet

AAT4618
Current Limited Load Switch
General Description
Features
The AAT4618 SmartSwitch is a member of
AnalogicTech's Application Specific Power MOSFET™ (ASPM™) product family. It is a current limited P-channel MOSFET power switch designed for
high-side load switching applications operating with
inputs ranging from 2.4V to 5.5V, making it ideal for
2.5V, 3V, and 5V systems. An integrated currentlimiting circuit protects the input supply from large
currents which may cause the supply to fall out of
regulation. In addition, the AAT4618 thermal overload protection limits power dissipation and junction
temperatures associated with prolonged periods of
operation in current limit. Due to its low RDS(ON), the
AAT4618 can be used to control loads that require
up to factory preset 400mA, 500mA, or 1A. The
ultra-fast current limit response to a sudden short
circuit is a mere 400ns which reduces the requirements of local supply bypassing. An open drain
FAULT flag signals an over-current or over-temperature condition after a 4ms timeout. Quiescent current is a low 10µA and the supply current decreases to less than 1µA in shutdown mode.
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SmartSwitch™
2.4V to 5.5V Input Voltage Range
Current Limit Trip Threshold Options:
— 400mA Min
— 500mA Min
— 1A Min
Fast Transient Response:
— 400ns Response to Short Circuit
Low Quiescent Current:
— 10µA Typical
— < 1µA with Switch Off
125mΩ Typical RDS(ON)
FAULT Flag with 4ms Blanking
Under-Voltage Lockout
Thermal Shutdown
Temperature Range: -40°C to +85°C
4kV ESD Rating
5-Pin SOT23 or 8-Pin SC70JW Package
Applications
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The AAT4618 is available in a Pb-free 5-pin SOT23 or a 8-pin SC70JW package and is specified
over the -40°C to +85°C temperature range.
The AAT4600 series is a family of adjustable and
fixed voltage SmartSwitch products with a range of
current handling capabilities. Single versions with
adjustable current limit (AAT4610, AAT4601) or
fixed current limit (AAT4625) are available, as well
as dual versions with fixed current limit (AAT4626,
AAT4670).
Hot Swap Supplies
Notebook Computers
Peripheral Ports
Personal Communication Devices
USB Ports
Typical Application
INPUT
OUTPUT
IN
OUT
AAT4618
100k
FAULT
CIN
1μF
GND
4618.2006.05.1.2
ON
(ON)
ON (ON)
GND
FAULT
COUT
0.47μF
GND
1
AAT4618
Current Limited Load Switch
Pin Descriptions
Pin #
SOT23-5
SC70JW-8
Symbol
Function
1
5
OUT
P-channel MOSFET drain.
2
6, 7, 8
GND
Ground connection.
3
1
FAULT
4
2
ON (ON)
5
3, 4
IN
Open-drain FAULT output.
Enable input: AAT4618 active low, AAT4618-1 active high.
P-channel MOSFET source.
Pin Configuration
SOT23-5
(Top View)
5
IN
2
3
4
ON (ON)
FAULT
ON (ON)
IN
IN
1
8
7
2
2
2
1
1
OUT
GND
FAULT
SC70JW-8
(Top View)
3
6
4
5
GND
GND
GND
OUT
4618.2006.05.1.2
AAT4618
Current Limited Load Switch
Absolute Maximum Ratings1
TA = 25°C, unless otherwise noted.
Symbol
Description
VIN, FAULT
VON
VOUT
IOUT
TJ
VESD
TLEAD
IN, FAULT to GND
ON (ON) to GND
OUT to GND
Output Current
Operating Junction Temperature Range
ESD Rating2—HBM
Maximum Soldering Temperature (at Leads)
Value
Units
-0.3 to 6
-0.3 to VIN + 1
-0.3 to VIN + 0.3
Internally Limited
-40 to 150
4000
300
V
V
V
A
°C
V
°C
Value
Units
150
667
°C/W
mW
Thermal Characteristics3
Symbol
ΘJA
PD
Description
Maximum Thermal Resistance
Maximum Power Dissipation
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time.
2. Human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin.
3. Mounted on a demo board.
4618.2006.05.1.2
3
AAT4618
Current Limited Load Switch
Electrical Characteristics
VIN = 5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C; bold values denote full
temperature range.
Symbol
VIN
IQ
IQ(OFF)
ISD(OFF)
VUVLO
VUVLO(hys)
Description
Operation Voltage
Quiescent Current
Off Supply Current
Off Switch Current
Under-Voltage Lockout
Under-Voltage Lockout
Hysteresis
RDS(ON)
On Resistance
TCRDS
On Resistance Temperature
Coefficient
ILIM
VON(L)
10
0.1
1.9
VIN = 5.0V, TA = 25°C
VIN = 3.0V, TA = 25°C
Max
Units
5.5
25
1
1
V
µA
µA
µA
V
125
155
V
175
225
2800
VIN = 2.7V to 5.5V1
VIN = 2.7V to ≤ 4.2V1
VIN = > 4.2V to 5.0V1
VON (ON) = 5.5V
VIN = 5V
VIN = 5V, RL = 20Ω
VIN = 5V, RL = 20Ω
ISINK = 1mA
ON (ON) Input Leakage
Current Loop Response
Turn-Off Time
Turn-On Time
FAULT Logic Output Low
FAULT Logic Output High
Leakage Current
Fault Blanking Time
Over-Temperature Threshold
Typ
0.3
ON (ON) Input Low Voltage
ION(SINK)
tRESP
TOFF
TON
VFAULTLOW
Tblank
TSD
VIN = 5V, ON (ON) = Active, IOUT = 0
ON (ON) = Inactive, VIN = 5.5V
ON (ON) = Inactive, VIN = 5.5V, VOUT = 0
VIN Falling
VOUT = VIN to 0.5V
ON (ON) Input High Voltage
Min
2.4
Current Limit
VON(H)
ISINK
Conditions
AAT4618-0.4
AAT4618-0.5
AAT4618-1.0
400 500
500 750
1000 1500
ppm/°C
600
1000
2000
0.8
VFAULT = 5.5V
0.5
VIN = 5V
4
125
mA
0.4
V
V
V
µA
ns
µs
µs
V
1
µA
2.0
2.4
0.01
400
5
1
mΩ
1
ms
°C
1. For VIN outside this range, consult Typical ON (ON) Threshold curve.
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4618.2006.05.1.2
AAT4618
Current Limited Load Switch
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA = 25°C.
Quiescent Current vs. Input Voltage
Quiescent Current vs. Temperature
20
Quiescent Current (μA)
Quiescent Current (μA)
20
15
10
5
0
-40
-20
0
20
40
60
80
100
15
10
5
0
0
120
1
2
1.2
220
200
180
160
1
0.8
0.6
0.4
0.2
0
2
3
4
140
120
100
80
60
VIN = 5V
40
20
0
-40
5
-20
0
20
40
60
80
100
120
Temperature (°C)
Off-Supply Current vs. Temperature
Off-Switch Current vs. Temperature
1.00
1.00
Off-Switch Current (μA)
Off-Supply Current (μA)
6
VIN = 3V
Output Voltage (V)
0.10
0.01
0.00
-40
5
RDS(ON) vs. Temperature
RDS(ON) (mΩ)
Normalized Current Limit
Normalized Current Limit vs. Output Voltage
1
4
Input Voltage (V)
Temperature (°C)
0
3
-20
0
20
40
60
Temperature (°C)
4618.2006.05.1.2
80
100
120
0.10
0.01
0.00
-40
-20
0
20
40
60
80
100
120
Temperature (°C)
5
AAT4618
Current Limited Load Switch
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA = 25°C.
Turn-Off
(RL = 20Ω; CL = 0.47µF)
6
5
5
ON
3
Voltage (V)
6
4
Voltage (V)
Turn-On
(RL = 20Ω; CL = 0.47µF)
OUT
2
1
4
ON
3
OUT
2
1
0
0
-1
-1
-0.5
0.0
0.5
1.0
1.5
-10
2.0
0
10
10
Output Current
8
Output Voltage
3
6
2
4
1
2
0
Output Voltage (5V/div)
Output Current (1A/div)
0
-1
0
1
2
50
12
Input Voltage
4
40
Thermal Shutdown Response
Output Current (A)
Input and Output Voltage (V)
Short Circuit Through 0.3Ω
5
30
Time (µs)
Time (µs)
6
20
3
4
5
Time (µs)
Time (50ms/div)
ON (ON) Threshold vs. Input Voltage
Fault Delay from Short Circuit
Output Voltage (5V/div)
Output Current (1A/div)
FAULT (5V/div)
ON (ON) Threshold (V)
2.4
2.2
2
1.8
VON(H)
1.6
1.4
VON(L)
1.2
1
0.8
0.6
0.4
2
Time (1ms/div)
6
2.5
3
3.5
4
4.5
5
5.5
Input Voltage (V)
4618.2006.05.1.2
AAT4618
Current Limited Load Switch
Functional Block Diagram
IN
OUT
Under-Voltage
Lockout
Over-Temperature
Protection
Current
Limit
FAULT
ON (ON)
4ms Delay
GND
Functional Description
The AAT4618 is a single channel current limited
load switch that protects against short circuits by
current limiting to a preset level. A patented fastacting current limit loop limits the current in a fraction of a microsecond and instantly resets to low
impedance once the short-circuit condition is
removed. The AAT4618 is internally protected
from thermal damage by an over-temperature
detection circuit. If the die temperature reaches
the internal thermal limit, the power device is
switched off until the die temperature cools to a
level below the thermal limit threshold. The device
will thermal cycle indefinitely until the over-current
condition is removed. The AAT4618 operates with
4618.2006.05.1.2
input voltages ranging from 2.4V to 5.5V which,
along with its extremely low operating current,
makes it ideal for battery-powered applications. In
cases where the input voltage drops below 2.4V,
the AAT4618 MOSFET is protected from entering
the saturated region of operation by being automatically shut down by an under-voltage lockout
circuit. A current limit condition is reported by the
open drain FAULT output. A 4ms blanking interval
prevents false reporting during the charging of a
capacitive load, which typically occurs during
device turn-on, but may also occur during a port
hot plug-in event.
The AAT4618 is ideally suited for protection of
peripheral ports such as USB, RS232, and parallel
ports.
7
AAT4618
Current Limited Load Switch
Applications Information
Input Capacitor
The input capacitor CIN protects the power supply
from current transients generated by the load
attached to the AAT4618. When a short circuit is
suddenly applied to the output of the AAT4618, a
large current, limited only by the RDS(ON) of the
MOSFET, will flow for less than 1µs before the current limit circuitry activates. (See characteristic
curve "Short Circuit Through 0.3Ω.") In this event,
a moderately sized CIN will dramatically reduce the
voltage transient seen by the power supply and by
other circuitry upstream from the AAT4618. The
extremely fast short-circuit response time of the
AAT4618 reduces the size requirement of CIN.
CIN should be located as close to the device VIN pin
as practically possible. Ceramic, tantalum, or aluminum electrolytic capacitors are appropriate for
CIN. There is no specific capacitor ESR requirement
for CIN. However, for higher current operation,
ceramic capacitors are recommended for CIN due to
their inherent capability over tantalum capacitors to
withstand input current surges from low impedance
sources such as batteries in portable devices.
Output Capacitor
In order to insure stability while current limit is
active, a low capacitance (approximately 0.47µF) is
required. No matter how large the output capacitor, output current is limited to the value set by the
AAT4618 current limiting circuitry, so very large
output capacitors can be used.
For example, USB ports are specified to have at
least 120µF of capacitance downstream from their
controlling power switch. The current limiting circuit
will allow an output capacitance of 1000µF or more
without disturbing the upstream power supply.
ON (Enable Input)
In many systems, power planes are controlled by
integrated circuits which run at lower voltages than
the power plane itself. The enable input (ON) of
the AAT4618 has low and high threshold voltages
that accommodate this condition. The threshold
voltages are compatible with 5V TTL and 2.5V to
5V CMOS systems.
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When switching the AAT4618 on into a capacitive
load, the AAT4618 will charge the output capacitive
load at a rate no greater than the current limit setting.
Attaching Loads
Capacitive loads attached to an enabled AAT4618 will
charge at a rate no greater than the current limit setting.
FAULT Output
The FAULT flag is provided to alert the system if an
AAT4618 load is not receiving sufficient voltage to
operate properly. If current limit or over-temperature circuits in any combination are active for more
than approximately 4ms, the FAULT flag is pulled
to ground through approximately 100Ω. The filtering of voltage or current transients of less than 4ms
prevents capacitive loads connected to the
AAT4618 output from activating the FAULT flag
when they are initially attached. Pull-up resistances of 1kΩ to 100kΩ are recommended. Since
FAULT is an open drain terminal, it may be pulled
up to any unrelated voltage less than the maximum
operating voltage of 5.5V, allowing for level shifting
between circuits.
Thermal Considerations
Since the AAT4618 has internal current limit and
over-temperature protection, junction temperature
is rarely a concern. However, if the application
requires large currents in a hot environment, it is
possible that temperature, rather than current limit,
will be the dominant regulating condition. In these
applications, the maximum current available without risk of an over-temperature condition must be
calculated. The maximum internal temperature
while current limit is not active can be calculated
using Equation 1.
Eq. 1: TJ(MAX) = IMAX2 · RDS(ON)(MAX) · RΘJA + TA(MAX)
In Equation 1, IMAX is the maximum current required
by the load. RDS(ON)(MAX) is the maximum rated
RDS(ON) of the AAT4618 at high temperature. RθJA is
the thermal resistance between the AAT4618 die
and the board onto which it is mounted. TA(MAX) is
the maximum temperature that the PCB under the
4618.2006.05.1.2
AAT4618
Current Limited Load Switch
AAT4618 would be if the AAT4618 were not dissipating power. Equation 1 can be rearranged to
solve for IMAX, as shown in Equation 2.
Eq. 2: IMAX =
For example, if an application is specified to operate in 50°C environments, the PCB operates at
temperatures as high as 85°C. The application is
sealed and its PCB is small, causing RθJA to be
approximately 150 °C/W. Using Equation 2,
TSD(MIN) - TA(MAX)
RDS(ON)(MAX) · RΘJA
Eq. 3: IMAX =
TSD(MIN) is the minimum temperature required to
activate the AAT4618 over-temperature protection.
With the typical specification of 125°C, 115°C is a
safe minimum value to use.
4618.2006.05.1.2
115 - 85
= 950mA
220 · 150
The AAT4618 is safe to operate at the minimum
current limit level of 500mA at 85°C.
9
AAT4618
Current Limited Load Switch
Ordering Information
Package
Enable
Current Limit
Marking1
Part Number (Tape and Reel)2
SOT23-5
SOT23-5
SOT23-5
SOT23-5
SC70JW-8
SC70JW-8
SC70JW-8
SC70JW-8
SC70JW-8
SC70JW-8
Active Low
Active High
Active Low
Active High
Active Low
Active High
Active Low
Active High
Active Low
Active High
0.5
0.5
1.0
1.0
0.4
0.4
0.5
0.5
1.0
1.0
AVXYY
DWXYY
EVXYY
EIXYY
AAT4618IGV-0.5-T1
AAT4618IGV-0.5-1-T1
AAT4618IGV-1.0-T1
AAT4618IGV-1.0-1-T1
AVXYY
DWXYY
EVXYY
EIXYY
AAT4618IJS-0.5-T1
AAT4618IJS-0.5-1-T1
AAT4618IJS-1.0-T1
AAT4618IJS-1.0-1-T1
All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means
semiconductor products that are in compliance with current RoHS standards, including
the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more
information, please visit our website at http://www.analogictech.com/pbfree.
Package Information
SOT23-5
2.85 ± 0.15
1.90 BSC
0.40 ± 0.10
0.075 ± 0.075
0.15 ± 0.07
4° ± 4°
10° ± 5°
1.10 ± 0.20
0.60 REF
1.20 ± 0.25
2.80 ± 0.20
1.575 ± 0.125
0.95
BSC
0.60 REF
0.45 ± 0.15
GAUGE PLANE
0.10 BSC
All dimensions in millimeters
1. XYY = assembly and date code.
2. Sample stock is generally held on all part numbers listed in BOLD.
10
4618.2006.05.1.2
AAT4618
Current Limited Load Switch
SC70JW-8
2.20 ± 0.20
1.75 ± 0.10
0.50 BSC 0.50 BSC 0.50 BSC
0.225 ± 0.075
2.00 ± 0.20
0.100
7° ± 3°
0.45 ± 0.10
4° ± 4°
0.05 ± 0.05
0.15 ± 0.05
1.10 MAX
0.85 ± 0.15
0.048REF
2.10 ± 0.30
All dimensions in millimeters.
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Fax (408) 737-4611
4618.2006.05.1.2
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