Datasheet AAT4280IJS-3-T1, AAT4280IJS-2-T1, AAT4280IJS-1-T1, AAT4280IGU-3-T1, AAT4280IGU-2-T1 Datasheet (Analogic Technologies)
...Page 1
AAT4280
Slew Rate Controlled Load Switch
General Description
The AAT4280 SmartSwitch™ is a member of AATI's
Application Specific Power MOSFET™ (ASPM™)
product family. The AAT4280 is a P-channel MOSFET power switch designed for high-side loadswitching applications. The P-channel MOSFET
device has a typical R
increased load switch power handling capacity. This
device is available in three different versions with
flexible turn on and off characteristics from very fast
to slew rate limited. The standard AAT4280 (-1) version has a slew rate limited turn on load switch and
is functionally compatible with the AAT4250 device
while offering superior R
AAT4280 (-2) version features fast load switch turn
on capabilities, typically less than 210ns turn on and
3µs turn off times. The AAT4280 (-3) variation offers
a shutdown load discharge circuit to rapidly turn off
a load circuit when the switch is disabled. All
AAT4280 load switch versions operate with an input
voltage ranging from 1.8V to 5.5V, making them
ideal for both 3V and 5V systems. The AAT4280
also features an under voltage lock out which turns
the switch off when an input under-voltage condition
exists. Input logic levels are TTL and 2.5 volt to 5
volt CMOS compatible. The quiescent supply current is very low, typically 2.5µA. In shutdown mode,
the supply current decreases to less than 1µA.
of 80mΩ, allowing
DS(ON)
characteristics. The
DS(ON)
SmartSwitch
Features
• 1.8V to 5.5V Input voltage range
• Very Low R
• Slew rate limited turn-on time options
•1ms
• 0.5µs
• 100µs
• Fast shutdown load discharge option
• Low quiescent current
• 2.5µA typ
• 1µA max in shutdown
• TTL/CMOS input logic level
• Temperature range -40ºC to 85°C
• 4kV ESD rating
• 6 pin SOT23 or SC70JW-8 package
Applications
• Cellular telephones
• Digital still cameras
• Personal digital assistants (PDA)
• Hot swap supplies
• Notebook computers
• Personal communication devices
, typically 80mΩ (5V)
DS(ON)
™
Preliminary Information
The AAT4280 is available in a 6 pin SOT23 or 8
pin SC70JW package and is specified over -40°C
to 85°C temperature range.
Typical Application
V
IN
IN
C
IN
1µF
GND
4280.2002.2.0.92 1
ON
ON/OFF
AAT4280
GND
GND
OUTIN
C
OUT
0.1µF
V
OUT
GND
Page 2
Pin Descriptions
Pin #
SOT23-6 SC70JW Symbol Function
1 2 OUT The pin is the P-channel MOSFET drain connection.
Bypass to ground through a 0.1uF capacitor.
2,5 4 GND Ground connection
3 3 ON/OFF Enable Input
4,6 1,5,6,7,8 IN The pin is the input to the P-channel MOSFET source.
Bypass to ground through a 1.0uF capacitor.
Pin Configuration
SOT23-6
(Top View)
AAT4280
Slew Rate Controlled Load Switch
Selector Guide
Part Number (typ) Pull Down Enable
OUT
GND
ON/OFF
IN
OUT
ON/OFF
GND
Slew Rate Active
1
2
3
SC70JW-8
(Top View)
1 2
1
2
3
4
6
5
4
8
7
6
5
IN
GND
IN
IN
IN
IN
IN
AAT4280-1 1mS Active High
AAT4280-2 0.5µS Active High
AAT4280-3 100µS √ Active High
2 4280.2002.2.0.92
Page 3
AAT4280
Slew Rate Controlled Load Switch
Absolute Maximum Ratings (T
=25°C unless otherwise noted)
A
Symbol Description Value Units
V
IN
V
ON
V
OUT
I
MAX
I
DM
T
J
T
LEAD
V
ESD
Note: 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.
Note 1: Human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin.
IN to GND -0.3 to 6 V
ON/OFF to GND -0.3 to 6 V
OUT to GND -0.3 to VIN+0.3 V
Maximum Continuous Switch Current 2.3 A
Maximum Pulsed Current
IN ≥ 2.5V 6 A
IN < 2.5V 3 A
Operating Junction Temperature Range -40 to 150 °C
Maximum Soldering Temperature (at Leads) 300 °C
ESD Rating1- HBM 4000 V
Thermal Characteristics
Value
Symbol Description
Θ
JA
P
D
Note 2: Mounted on an AAT4280 demo board in still 25ºC air.
Thermal Resistance (SOT23-6 or SC70JW-8)
Power Dissipation (SOT23-6 or SC70JW-8)
SOT23-6 SC70JW-8
2
2
120 140 °C/W
833 714 mW
Units
4280.2002.2.0.92 3
Page 4
AAT4280
Slew Rate Controlled Load Switch
Electrical Characteristics (V
= 5V, TA= -40 to 85°C unless otherwise noted. Typical values
IN
are at TA=25°C)
Symbol Description Conditions Min Typ Max Units
AAT4280 All Versions
V
V
UVLO
V
UVLO(hys)
I
Operation Voltage 1.8
IN
Undervoltage Lockout VINfalling 1.0 1.4 1.8 V
Undervoltage Lockout Hysteresis 250 mV
Quiescent Current ON/OFF= active 2.5 4 uA
Q
IQ(off) Off supply current ON/OFF= inactive, OUT=open 1 uA
ISD(off) Off switch current ON/OFF= inactive, V
R
DS(on)
On -resistance VIN=5V, T
=25° C 80 120 mΩ
A
=0 1 uA
OUT
VIN=4.2V, TA=25° C 85 130
VIN=3V, TA=25° C 100 150
VIN=1.8V, TA=25° C 160 250
TC
V
V
On-Resistance Temp -Co 2800 ppm/°C
RDS
ON/OFF Input Logic Low Voltage VIN=2.7V-5.5V
IL
ON/OFF Input Logic High Voltage V
IH
=2.7V to ≤ 4.2V 2 V
IN
4
VIN= >4.2V to 5.5V 2.4 V
I
SINK
ON/OFF Input Leakage V
= 5.5V 1 uA
ON/OFF
AAT4280-1
T
D(ON)
T
T
D(OFF)
ON
Output Turn-On Delay V
Output Turn-On rise time V
Output Turn-Off delay time V
=5V, R
IN
=5V, R
IN
=5V, R
IN
=10Ω , T
LOAD
=10Ω, TA=25° C 1000 1500 uS
LOAD
=10Ω, TA=25° C 4 10 uS
LOAD
=25° C 20 40 uS
A
AAT4280-2
T
D(ON)
T
T
D(OFF)
ON
Output Turn-On Delay V
Output Turn-On rise time V
Output Turn-Off delay time V
=5V, R
IN
=5V, R
IN
=5V, R
IN
LOAD
LOAD
LOAD
=10Ω , T
=10Ω , T
=10Ω , T
=25° C 0.5 2 uS
A
=25° C 0.5 1 uS
A
=25° C 4 10 uS
A
AAT4280-3
T
D(ON)
T
ON
T
D(OFF)
R
Note 3: Part requires minimum start-up of V
Note 4: For V
Output Turn-On Delay V
Output Turn-On rise time V
Output Turn_Off delay time V
Output pull-down resistance during OFF ON/OFF = inactive, T
PD
≥ 2.0V to ensure operation down to 1.8V
outside this range consult typical ON/OFF threshold curve.
IN
IN
=5V, R
IN
=5V, R
IN
=5V, R
IN
LOAD
LOAD
LOAD
=10Ω , T
=10Ω , T
=10Ω , T
=25° C 20 40 uS
A
=25° C 100 150 uS
A
=25° C 4 10 uS
A
=25° C 150 250 Ω
A
3
5.5 V
0.8 V
4 4280.2002.2.0.92
Page 5
Typical Characteristics
0
0
0
(Unless otherwise noted, VIN= 5V, TA= 25°C)
AAT4280
Slew Rate Controlled Load Switch
Quiescent Current vs. Temperature
4
vs. V
VIN (V)
VIN=5V
VIN=3V
IN
3
2
(µA)
Q
I
1
0
-40-20 0 2040 608010
Temperature (°C)
R
DS(ON)
(mΩ)
DS(ON)
R
190
170
150
130
110
90
70
2A
1A
500mA
100mA
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
Quiescent Current vs. Input Voltage
3.5
3.0
2.5
2.0
1.5
1.0
0.5
Quiescent Current (µA)
0.0
0 123456
V
(V)
IN
R
vs. Temperature
DS(ON)
120
110
100
90
(mΩ)
80
70
DS(ON)
R
60
50
40
-40 -20 0 20 40 60 80 10
VIN=3V
VIN=5V
Temperature (°C)
ON/OFF Threshold vs. V
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
ON/OFF Threshold (V)
0.4
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
V
IH
V
IL
V
(V)
IN
IN
(µA)
I
Off Switch Current vs. Temperature
1.000
0.100
0.010
OFFSW
0.001
-40 -20 0 20 40 60 80 10
Temperature (°C)
4280.2002.2.0.92 5
Page 6
Typical Characteristics—4280-1
(Unless otherwise noted, VIN= 5V, TA= 25°C)
AAT4280
Slew Rate Controlled Load Switch
AAT4280-1 Turn-On
VIN=3V R
ON/OFF (5V/div.)
Time (500µs/div.)
AAT4280-1 Turn-Off
VIN=3V R
=6Ω
L
V
(2V/div.)
OUT
IIN (200mA/div.)
=6Ω
L
ON/OFF (5V/div.)
V
OUT
(2V/div.)
AAT4280-1 Turn-On
VIN=5V R
ON/OFF (5V/div.)
Time (500µs/div.)
L
AAT4280-1 Turn-Off
VIN=5V R
=10Ω
L
=10Ω
V
(2V/div.)
OUT
IIN (200mA/div.)
ON/OFF (5V/div.)
V
(2V/div.)
OUT
Time (10µs/div)
IIN (200mA/div.)
Time (10µs/div.)
IIN (200mA/div.)
6 4280.2002.2.0.92
Page 7
Typical Characteristics—4280-2
(Unless otherwise noted, VIN= 5V, TA= 25°C)
AAT4280
Slew Rate Controlled Load Switch
AAT4280-2 Turn-On
VIN=3V R
Time (5µs/div.)
=6Ω
L
ON/OFF (5V/div.)
V
IIN (200mA/div.)
AAT4280-2 Turn-Off
VIN=3V R
=6Ω
L
ON/OFF (5V/div.)
V
OUT
(2V/div.)
OUT
(2V/div.)
AAT4280-2 Turn-On
VIN=5V R
Time (5µs/div.)
=10Ω
L
ON/OFF (5V/div.)
V
OUT
IIN (200mA/div.)
AAT4280-2 Turn-Off
VIN=5V R
=10Ω
L
ON/OFF (5V/div.)
V
(2V/div.)
(2V/div.)
OUT
IIN (200mA/div.)
Time (5µs/div.)
4280.2002.2.0.92 7
Time (5µs/div.)
IIN (200mA/div.)
Page 8
Typical Characteristics—4280-3
(Unless otherwise noted, VIN= 5V, TA= 25°C)
AAT4280
Slew Rate Controlled Load Switch
AAT4280-3 Turn-On
VIN=3V R
Time (50µs/div.)
=6Ω
L
ON/OFF (5V/div.)
V
IIN (200mA/div.)
AAT4280-3 Turn-Off
VIN=3V R
=6Ω
L
ON/OFF (5V/div.)
V
(2V/div.)
OUT
(2V/div.)
OUT
AAT4280-3 Turn-On
VIN=5V R
Time (50µs/div.)
=10Ω
L
ON/OFF (5V/div.)
V
(2V/div.)
OUT
IIN (200mA/div.)
AAT4280-3 Turn-Off
VIN=5V R
=10Ω
L
ON/OFF (5V/div.)
V
(2V/div.)
OUT
IIN (200mA/div.)
Time (5µs/div.)
Time (5µs/div.)
IIN (200mA/div.)
8 4280.2002.2.0.92
Page 9
Functional Block Diagram
AAT4280
Slew Rate Controlled Load Switch
IN
Under
Voltage
Lockout
Level
Shift
ON/OFF
Functional Description
The AAT4280 is a family of flexible P-channel
MOSFET power switches designed for high-side
load-switching applications. There are three versions of AAT4280 with different turn-on and turn-off
characteristics to choose from, depending upon the
specific requirements of an application. The first
AAT4280-1 version has a moderate turn on slew
rate feature, which reduces in-rush current when
the MOSFET is turned on. This function allows the
load switch to be implemented with a small input
capacitor, or no input capacitor at all. During turn
on slewing, the current ramps linearly until it reaches the level required for the output load condition.
The proprietary turn on current control method
works by careful control and monitoring of the
MOSFET gate voltage. When the device is
switched ON, the gate voltage is quickly increased
to the threshold level of the MOSFET. Once at this
level, the current begins to slew as the gate voltage
is slowly increased until the MOSFET becomes
fully enhanced. Once it has reached this point, the
OUT
Turn-On
Slew Rate
Control
*
GND
*AAT4280-3 only
gate is quickly increased to the full input voltage
and R
sion, the AAT4280-2 is a very fast switch intended
for high speed switching applications. This version
has no turn on slew rate control and no special output discharge features. The final switch version,
the AAT4280-3 has the addition of a minimized
slew rate limited turn on function and a shutdown
output discharge circuit to rapidly turn off a load
when the load switch is disabled through the
ON/OFF pin.
All versions of the AAT4280 operate with input voltages ranging from 1.8V to 5.5V. All versions of this
device have extremely low operating current, making them ideal for battery-powered applications. In
cases where the input voltage drops below 1.8V,
the AAT4280 MOSFET device is protected from
entering into the saturation region of operation by
automatically shutting down through an under voltage lockout control circuit. The ON/OFF control pin
is TTL compatible and will also function with 2.5
volt to 5 volt logic systems, making the AAT4280 an
ideal level shifting load-switch.
is minimized. The second device ver-
DS(ON)
4280.2002.2.0.92 9
Page 10
AAT4280
Slew Rate Controlled Load Switch
Applications Information
Input Capacitor
Typically a 1µF or larger capacitor is recommended for CINin most applications. A CINcapacitor is
not required for basic operation. However, CINis
useful in preventing load transients from affecting
upstream circuits. CINshould be located as close
to the device VINpin as practically possible.
Ceramic, tantalum or aluminum electrolytic capacitors may be selected for CIN. There is no specific
capacitor ESR requirement for CIN. However, for
higher current operation, ceramic capacitors are
recommended for CINdue to their inherent capability over tantalum capacitors to withstand input current surges from low impedance sources such as
batteries in portable devices.
Output Capacitor
For proper slew operation, a 0.1µF capacitor or
greater between V
The output capacitor has no specific capacitor type
or ESR requirement. If desired, C
increased without limit to accommodate any load
transient condition without adversely affecting the
device turn on slew rate time.
Enable Function
The AAT4280 features an enable / disable function.
This pin (ON/OFF) is compatible with both TTL or
CMOS logic.
Reverse Output to Input Voltage
Conditions and Protection
Under normal operating conditions a parasitic
diode exists between the output and input of the
load switch. The input voltage should always
remain greater than the output load voltage maintaining a reverse bias on the internal parasitic
diode. Conditions where V
should be avoided since this would forward bias
the internal parasitic diode and allow excessive
current flow into the V
to the load switch.
In applications where there is a possibility of V
exceeding VINfor brief periods of time during normal operation, the use of a larger value CINcapaci-
and GND is recommended.
OUT
OUT
might exceed V
OUT
pin and possible damage
OUT
may be
OUT
tor is highly recommended. A larger value of C
with respect to C
rate during shutdown, thus preventing V
will effect a slower CINdecay
OUT
OUT
IN
from
exceeding VIN. In applications where there is a
greater danger of V
exceeding VINfor extended
OUT
periods of time, it is recommended to place a schottky diode from VINto V
to VINand anode to V
(connecting the cathode
OUT
). The Schottky diode for-
OUT
ward voltage should be less then 0.45 volts.
Thermal Considerations and High
Output Current Applications
The AAT4280 is designed to deliver a continuous
output load current. The limiting characteristic for
maximum safe operating output load current is
package power dissipation. In order to obtain high
operating currents, careful device layout and circuit
operating conditions need to be taken into account.
The following discussions will assume the load
switch is mounted on a printed circuit board utilizing the minimum recommended footprint as stated
in the layout considerations section.
At any given ambient temperature (TA) the maximum package power dissipation can be determined by the following equation:
P
Constants for the AAT4280 are maximum junction
temperature, T
resistance, ΘJA= 120°C/W. Worst case conditions
are calculated at the maximum operating temperature where TA= 85°C. Typical conditions are calculated under normal ambient conditions where T
= 25°C. At TA= 85°C, P
25°C, P
D(MAX)
The maximum continuous output current for the
AAT4280 is a function of the package power dissi-
IN
pation and the RDSof the MOSFET at T
maximum RDSof the MOSFET at T
lated by increasing the maximum room temperature
RDSby the RDStemperature coefficient. The temperature coefficient (TC) is 2800ppm/°C. Therefore,
MAX RDS125°C = RDS25°C × (1 + TC ×∆T)
MAX RDS125°C = 120mΩ×(1 + 0.0028 ×
(125°C - 25°C)) = 154mΩ
= [T
D(MAX)
J(MAX)
= 833mW.
- TA] / Θ
J(MAX)
JA
= 125°C, and package thermal
= 333mW. At TA=
D(MAX)
. The
J(MAX)
is calcu-
J(MAX)
A
10 4280.2002.2.0.92
Page 11
AAT4280
Slew Rate Controlled Load Switch
For maximum current, refer to the following equation:
I
OUT(MAX)
For example, if V
= 25°C, I
OUT(MAX)
< ( P
D(MAX)
= 5V, R
IN
DS(MAX)
= 2.3A. If the output load current
1/2
/ RDS)
=154mΩ and T
were to exceed 2.3A or if the ambient temperature
were to increase, the internal die temperature will
increase, and the device will be damaged.
Higher peak currents can be obtained with the
AAT4280. To accomplish this, the device thermal
resistance must be reduced by increasing the heat
sink area or by operating the load switch in a duty
cycle manner.
High Peak Output Current Applications
Some applications require the load switch to operate at a continuous nominal current level with short
duration high current peaks. The duty cycle for
both output current levels must be taken into
account. To do so, first calculate the power dissipation at the nominal continuous current level, and
then add in the additional power dissipation due to
the short duration high current peak scaled by the
duty factor.
For example, a 4V system using an AAT4280 operates at a continuous 100mA load current level and
has short 2A current peaks, as in a GSM application. The current peak occurs for 576µs out of a
4.61ms period.
First, the current duty cycle is calculated:
% Peak Duty Cycle: X/100 = 576µs/4.61ms
% Peak Duty Cycle = 12.5%
The load current is 100mA for 87.5% of the 4.61ms
period and 2A for 12.5% of the period. Since the
Electrical Characteristics do not report R
DS(MAX)
4 volt operation, it must be calculated approximately by consulting the chart of R
DS(ON)
The RDSreported for 5 volts can be scaled by the
for
vs. VIN.
ratio seen in the chart to derive the RDSfor a 4 volt
VIN: 120mΩ×87mΩ /80mΩ = 130mΩ . De-rated
for temperature: 130mΩ x (1 + .0028 × (125°C -
A
25°C)) = 166mΩ . The power dissipation for a
100mA load is calculated as follows:
P
D(MAX)
P
D(100mA)
P
D(100mA)
P
D(87.5%D/C)
P
D(87.5%D/C)
P
D(87.5%D/C)
2
= I
OUT
× R
DS
= (100mA)2 × 166mΩ
= 1.66mW
= %DC × P
D(100mA)
= 0.875 × 1.66mW
= 1.45mW
The power dissipation for 100mA load at 87.5%
duty cycle is 1.45mW. Now the power dissipation
for the remaining 12.5% of the duty cycle at 2A is
calculated:
P
D(MAX)
P
= (2A)2 × 166mΩ
D(2A)
P
= 664mW
D(2A)
P
D(12.5%D/C)
P
D(12.5%D/C)
P
D(12.5%D/C)
2
= I
OUT
× R
DS
= %DC × P
= 0.125 × 664mW
= 83mW
D(2A)
The power dissipation for 2A load at 12.5% duty
cycle is 83mW. Finally, the two power figures are
summed to determine the total true power dissipation under the varied load.
P
P
P
= P
D(total)
D(total)
D(total)
D(100mA)
= 1.45mW + 83mW
= 84.5mW
+ P
D(2A)
The maximum power dissipation for the AAT4280
operating at an ambient temperature of 85°C is
333mW. The device in this example will have a
total power dissipation of 84.5mW. This is well with
in the thermal limits for safe operation of the
device, in fact, at 85°C, the AAT4280 will handle a
2A pulse for up to 50% duty cycle. At lower ambient temperatures the duty cycle can be further
increased.
4280.2002.2.0.92 11
Page 12
AAT4280
Slew Rate Controlled Load Switch
Printed Circuit Board Layout
Recommendations
For proper thermal management, and to take
advantage of the low R
circuit board layout rules should be followed: V
and V
traces, and GND should be connected to a ground
plane. To maximize package thermal dispation and
power handling capacity of the AAT4280 SOT23-6/
SC70JW-8 package, the ground plane area connected to the ground pins should be made as large
as possible. For best performance, CINand C
should be placed close to the package pins.
should be routed using wider than normal
OUT
of the AAT4280, a few
DS(ON)
OUT
Evaluation Board Layout
The AAT4280 evaluation layout follows the printed
circuit board layout recommendations, and can be
used for good applications layout. Refer to Figures
IN
1 through 3.
Note: Board layout shown is not to scale.
Figure 1: Evaluation board Figure 2: Evaluation board Figure 3: Evaluation board
top side silk screen layout / component side layout solder side layout
assembly drawing
12 4280.2002.2.0.92
Page 13
Ordering Information
AAT4280
Slew Rate Controlled Load Switch
Device Option Package Marking
Bulk Tape and Reel
AAT4280-1 SOT23-6 N/A AAT4280IGU-1-T1
AAT4280-2 SOT23-6 N/A AAT4280IGU-2-T1
AAT4280-3 SOT23-6 N/A AAT4280IGU-3-T1
AAT4280-1 SC70JW-8 N/A AAT4280IJS-1-T1
AAT4280-2 SC70JW-8 N/A AAT4280IJS-2-T1
AAT4280-3 SC70JW-8 N/A AAT4280IJS-3-T1
Package Information
SOT23-6
Part Number
e1
e
t
Dim
A 1.00 1.30 0.039 0.051
L2
A1 0.00 0.10 0.000 0.004
A2 0.70 0.90 0.028 0.035
b 0.35 0.50 0.014 0.020
E
c 0.10 0.25 0.004 0.010
D 2.70 3.10 0.106 0.122
E 1.40 1.80 0.055 0.071
L
e 1.90 0.075
H 2.60 3.00 0.102 0.118
L 0.37 0.015
f
D
C
S 0.45 0.55 0.018 0.022
S1 0.85 1.05 0.033 0.041
Θ 1° 9° 1° 9°
Millimeters Inches
Min Max Min Max
A2 A
b
A1
4280.2002.2.0.92 13
GAUGE PLANE
Page 14
SC70JW-8
AAT4280
Slew Rate Controlled Load Switch
eee
Dim
Millimeters Inches
Min Max Min Max
E 2.10 BSC 0.083 BSC
E1 1.75 2.00 0.069 0.079
E
L 0.23 0.40 0.009 0.016
A 1.10 0.043
A1 0 0.10 0.004
A2 0.70 1.00 0.028 0.039
D 2.00 BSC 0.079 BSC
b
D
c
A2
A
Θ1
L
E1
0.048REF
Θ
A1
e 0.50 BSC 0.020 BSC
b 0.15 0.30 0.006 0.012
c 0.10 0.20 0.004 0.008
Θ 08º08º
Θ 1 4º 10º 4º 10º
Advanced Analogic Technologies, Inc.
1250 Oakmead Parkway, Suite 310, Sunnyvale, CA 94086
Phone (408) 524-9684
Fax (408) 524-9689
14 4280.2002.2.0.92
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