ANALOGICTECH AAT3201IGV-2.85-T1

AAT3201
150mA OmniPower™ LDO Linear Regulator
General Description
Features
The AAT3201 PowerLinear OmniPower low dropout
(LDO) linear regulator is ideal for systems where a
low-cost solution is critical. This device features
extremely low quiescent current, typically 20µA.
Dropout voltage is also very low, typically 200mV.
The AAT3201 has an enable pin feature which,
when pulled low, will enter the LDO regulator into
shutdown mode, removing power from its load and
offering extended power conservation capabilities
for portable, battery-powered applications.
•
•
•
•
•
•
•
•
•
•
The AAT3201 has output short-circuit and overcurrent protection. In addition, the device has an
over-temperature protection circuit that will shut
down the LDO regulator during extended over-current events.
•
PowerLinear™
20µA Quiescent Current
Low Dropout: 200mV (typical)
Guaranteed 150mA Output
High Accuracy: ±2%
Current Limit Protection
Over-Temperature Protection
Extremely Low Power Shutdown Mode
Low Temperature Coefficient
Factory-Programmed Output Voltages
— 1.8V to 3.5V
Stable Operation With Virtually Any Output
Capacitor Type
5-Pin SOT23 Package
Applications
The AAT3201 is available in the Pb-free, space-saving 5-pin SOT23 package. The device is rated over
the -40°C to +85°C temperature range. Since only
a small, 1µF ceramic output capacitor is recommended, the AAT3201 is a truly cost-effective voltage conversion solution.
•
•
Cellular Phones
Consumer Electronics
The AAT3201 is similar to the AAT3200 with the
exception that it offers further power savings with
its enable pin.
Typical Application
INPUT
OUTPUT
OUT
IN
AAT3201
ENABLE
CIN
1µF
GND
3201.2006.01.1.2
EN
GND
COUT
1µF
GND
1
AAT3201
150mA OmniPower™ LDO Linear Regulator
Pin Descriptions
Pin #
Symbol
Function
1
IN
Input pin.
2
GND
3
EN
Enable pin; when pulled low, the PMOS pass transistor turns off and all
internal circuitry enters low-power mode, consuming less than 1µA.
4
NC
Not connected.
5
OUT
Ground connection pin.
Output pin; should be decoupled with 1µF or greater capacitor.
Pin Configuration
SOT23-5
(Top View)
2
IN
1
GND
2
EN
3
5
OUT
4
NC
3201.2006.01.1.2
AAT3201
150mA OmniPower™ LDO Linear Regulator
Absolute Maximum Ratings1
TA = 25°C, unless otherwise noted.
Symbol
VIN
VEN
VENIN(MAX)
IOUT
TJ
TLEAD
Description
Input Voltage
EN to GND Voltage
Maximum EN to Input Voltage
Maximum DC Output Current
Operating Junction Temperature Range
Maximum Soldering Temperature (at leads, 10 sec)
Value
Units
-0.3 to 6
-0.3 to 6
0.3
PD/(VIN-VO)
-40 to 150
300
V
V
V
mA
°C
°C
Thermal Information2
Symbol
ΘJA
PD
Description
Thermal Resistance
Power Dissipation
Rating
Units
150
667
°C/W
mW
Rating
Units
(VOUT+VDO) to 5.5
-40 to +85
V
°C
Recommended Operating Conditions
Symbol
VIN
T
Description
Input Voltage
Ambient Temperature Range
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. Mounted on a demo board.
3201.2006.01.1.2
3
AAT3201
150mA OmniPower™ LDO Linear Regulator
Electrical Characteristics
VIN = VOUT(NOM) + 1V, IOUT = 1mA, COUT = 1µF; TA = 25°C, unless otherwise noted.
Symbol
VOUT
IOUT
ISC
IQ
ISD
∆VOUT/VOUT
Description
DC Output Voltage Tolerance
Maximum Output Current
Short-Circuit Current
Ground Current
Shutdown Current
Line Regulation
∆VOUT/VOUT
Load Regulation
VDO
Dropout Voltage1
VEN(L)
VEN(H)
IEN(SINK)
PSRR
TSD
THYS
eN
TC
Conditions
VOUT > 1.2V
VOUT < 0.4V
VIN = 5V, No Load
EN = Inactive
VIN = 4.0V to 5.5V
VOUT =
VOUT =
VOUT =
VOUT =
VOUT =
IL= 1 to 100mA VOUT =
VOUT =
VOUT =
VOUT =
VOUT =
VOUT =
VOUT =
VOUT =
VOUT =
VOUT =
VOUT =
IOUT = 100mA
VOUT =
VOUT =
VOUT =
VOUT =
VOUT =
VOUT =
EN Input Low Voltage
EN Input High Voltage
EN Input leakage
Power Supply Rejection Ratio
Over-Temperature Shutdown
Threshold
Over-Temperature Shutdown
Hysteresis
Output Noise
Output Voltage Temperature
Coefficient
VIN = 5V
VON = 5.5V
100Hz
Min
Typ
-2.0
150
350
20
0.15
1.0
0.9
0.8
0.8
0.8
0.7
0.7
0.7
0.6
0.5
0.5
290
265
230
220
210
200
190
190
190
180
180
1.8
2.0
2.3
2.4
2.5
2.7
2.8
2.85
3.0
3.3
3.5
1.8
2.0
2.3
2.4
2.5
2.7
2.8
2.85
3.0
3.3
3.5
Max
Units
2.0
%
mA
mA
µA
µA
%/V
30
1
0.6
1.65
1.60
1.45
1.40
1.35
1.25
1.20
1.20
1.15
1.00
1.00
410
385
345
335
335
310
305
300
295
295
290
0.8
2.4
0.01
50
140
1
%
mV
V
V
µA
dB
°C
20
°C
350
80
µVRMS
PPM/°C
1. VDO is defined as VIN - VOUT when VOUT is 98% of nominal.
4
3201.2006.01.1.2
AAT3201
150mA OmniPower™ LDO Linear Regulator
Typical Characteristics
Unless otherwise noted, VIN = VOUT + 1V, TA = 25°C, COUT = 5.6µF ceramic, IOUT = 100mA.
Output Voltage vs. Input Voltage
3.03
3.1
3.02
3
Output Voltage (V)
Output Voltage (V)
Output Voltage vs. Output Current
3.01
-30°C
3
25°C
2.99
80°C
2.98
40mA
2.8
2.7
10mA
2.6
2.5
2.97
0
20
40
60
80
2.7
100
2.9
3.3
3.5
Input Voltage (V)
Output Voltage vs. Input Voltage
Dropout Voltage vs. Output Current
40 0
Dropout Voltage (mV)
1mA
3.02
10mA
3.01
40mA
3
300
80°C
200
25°C
-30°C
100
0
2.99
3.5
4
4.5
5
0
5.5
25
Input Voltage (V)
75
100
125
150
Noise Spectrum
60
Noise (dB µV/rt Hz )
30
40
20
0
1.E+01
50
Output Current (mA)
PSRR With 10mA Load
PSRR (dB)
3.1
Output Current (mA)
3.03
Output Voltage (V)
1mA
2.9
1.E+02
1.E+03
Frequency (Hz)
1.E+04
1.E+05
20
10
0
-10
-20
-30
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
Freque ncy (Hz)
3201.2006.01.1.2
5
AAT3201
150mA OmniPower™ LDO Linear Regulator
Typical Characteristics
Unless otherwise noted, VIN = VOUT + 1V, TA = 25°C, COUT = 5.6µF ceramic, IOUT = 100mA.
Load Transient – 1mA/40mA
Line Response With 1mA Load
3.4
4
3.2
3
3
2
Output
2.8
1
0
200
400
600
Input Voltage ( V )
Output Voltage ( V )
5
Input
0
800
320
240
Output
3
160
80
2
0
-1
0
Time (µs)
6
3.4
4
3.2
3
3
2
Output
2.8
1
600
0
800
Output Voltage (V)
4
5
Input
400
3
320
240
Output
3
160
80
2
0
-1
Time (µs)
Output Current (mA)
3.6
200
2
Load Transient – 1mA/80mA
Input Voltage ( V )
Output Voltage ( V )
3.8
0
1
Time (ms)
Line Response With 10mA Load
2.6
-200
Output Current (mA)
3.6
2.6
-200
4
6
Output Voltage (V)
3.8
0
1
2
3
Time (ms)
Line Response With 100mA Load
6
3.8
Output Voltage ( V )
Input
3.4
4
3.2
3
3
2
Output
2.8
2.6
-200
1
0
200
400
600
Input Voltage ( V )
5
3.6
0
800
Time (µs)
6
3201.2006.01.1.2
AAT3201
150mA OmniPower™ LDO Linear Regulator
Typical Characteristics
Unless otherwise noted, VIN = VOUT + 1V, TA = 25°C, COUT = 5.6µF ceramic, IOUT = 100mA.
Power-Up With 1mA Load
Turn-On With 1mA Load
4
5
4
3
3
2
1
0
1
-1
Output
Output Voltage (V)
2
Enable
2
1
1
0
Output
-2
0
0
-3
-1
Enable
2
0
1
Enable Voltage (V)
3
Input Voltage (V)
Output Voltage (V)
4
3
-1
-1
2
0
1
2
Time (ms)
Time (ms)
Turn-On With 10mA Load
Power-Up With 10mA Load
4
5
4
3
3
2
2
1
0
1
-1
Output
Output Voltage (V)
2
Enable
1
1
0
Output
-2
0
0
-3
-1
Enable
2
0
1
Enable Voltage (V)
3
Input Voltage (V)
Output Voltage (V)
4
3
-1
-1
2
0
1
2
Time (ms)
Time (ms)
Turn-On With 100mA Load
Power-Up With 100mA Load
4
5
4
3
3
2
2
2
1
Enable
0
1
-1
Output
-3
0
1
Time (ms)
3201.2006.01.1.2
Enable
2
2
1
1
0
Output
-2
0
-1
Output Voltage (V)
3
Enable Voltage (V)
3
Input Voltage (V)
Output Voltage (V)
4
0
-1
-1
0
1
2
Time (ms)
7
AAT3201
150mA OmniPower™ LDO Linear Regulator
Functional Block Diagram
IN
OUT
Over-Current
Protection
Over-Temperature
Protection
EN
VREF
GND
Functional Description
The AAT3201 is intended for LDO regulator applications where output current load requirements
range from no load to 150mA. The advanced circuit
design of the AAT3201 has been optimized for use
as the most cost-effective solution. The typical quiescent current level is just 20µA. The AAT3201
also contains an enable circuit, which has been provided to shut down the LDO regulator for additional
power conservation in portable products. In the
shutdown state, the LDO draws less than 1µA from
input supply.
The LDO also demonstrates excellent power supply rejection ratio (PSRR), and load and line transient response characteristics.
8
The LDO regulator output has been specifically
optimized to function with low-cost, low-equivalent
series resistance (ESR) ceramic capacitors.
However, the design will allow for operation with a
wide range of capacitor types.
The AAT3201 has complete short-circuit and thermal protection. The integral combination of these
two internal protection circuits gives the AAT3201 a
comprehensive safety system to guard against
extreme adverse operating conditions. Device
power dissipation is limited to the package type
and thermal dissipation properties. Refer to the
Thermal Considerations section of this datasheet
for details on device operation at maximum output
load levels.
3201.2006.01.1.2
AAT3201
150mA OmniPower™ LDO Linear Regulator
Applications Information
To assure the maximum possible performance is
obtained from the AAT3201, please refer to the following application recommendations.
needed can be calculated from the step size of the
change in output load current expected and the
voltage excursion that the load can tolerate.
The total output capacitance required can be calculated using the following formula:
Input Capacitor
Typically, a 1µF or larger capacitor is recommended
for CIN in most applications. A CIN capacitor is not
required for basic LDO regulator operation.
However, if the AAT3201 is physically located any
distance more than one or two centimeters from the
input power source, a CIN capacitor will be needed
for stable operation. CIN should be located as
closely to the device VIN pin as practically possible.
CIN values greater than 1µF will offer superior input
line transient response and will assist in maximizing
the power supply ripple rejection.
Ceramic, tantalum, or aluminum electrolytic capacitors may be selected for CIN as there is no specific capacitor ESR requirement. For 150mA LDO
regulator output 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.
COUT =
∆I
× 15µF
∆V
Where:
∆I = maximum step in output current
∆V = maximum excursion in voltage that the load
can tolerate
Note that use of this equation results in capacitor
values approximately two to four times the typical
value needed for an AAT3201 at room temperature.
The increased capacitor value is recommended if
tight output tolerances must be maintained over
extreme operating conditions and maximum operational temperature excursions. If tantalum or aluminum electrolytic capacitors are used, the capacitor
value should be increased to compensate for the
substantial ESR inherent to these capacitor types.
Capacitor Characteristics
Output Capacitor
For proper load voltage regulation and operational
stability, a capacitor is required between pins VOUT
and GND. The COUT capacitor connection to the
LDO regulator ground pin should be made as direct
as practically possible for maximum device performance. The AAT3201 has been specifically
designed to function with very low ESR ceramic
capacitors. Although the device is intended to operate with these low ESR capacitors, it is stable over
a very wide range of capacitor ESR, thus it will also
work with some higher ESR tantalum or aluminum
electrolytic capacitors. However, for best performance, ceramic capacitors are recommended.
The value of COUT typically ranges from 0.47µF to
10µF; however, 1µF is sufficient for most operating
conditions.
If large output current steps are required by an
application, then an increased value for COUT
should be considered. The amount of capacitance
3201.2006.01.1.2
Ceramic composition capacitors are highly recommended over all other types of capacitors for use
with the AAT3201. Ceramic capacitors offer many
advantages over their tantalum and aluminum electrolytic counterparts. A ceramic capacitor typically
has very low ESR, is lower cost, has a smaller PCB
footprint, and is non-polarized. Line and load transient response of the LDO regulator is improved by
using low ESR ceramic capacitors. Since ceramic
capacitors are non-polarized, they are less prone
to damage if incorrectly connected.
Equivalent Series Resistance: ESR is an important characteristic to consider when selecting a
capacitor. ESR is the internal series resistance
associated with a capacitor that includes lead
resistance, internal connections, capacitor size and
area, material composition, and ambient temperature. Typically capacitor ESR is measured in milliohms for ceramic capacitors and can range to
more than several ohms for tantalum or aluminum
electrolytic capacitors.
9
AAT3201
150mA OmniPower™ LDO Linear Regulator
Ceramic Capacitor Materials: Ceramic capacitors
less than 0.1µF are typically made from NPO or
C0G materials. NPO and C0G materials generally
have tight tolerance and are very stable over temperature. Larger capacitor values are usually composed of X7R, X5R, Z5U, or Y5V dielectric materials. Large ceramic capacitors (i.e., greater than
2.2µF) are often available in low-cost Y5V and Z5U
dielectrics. These two material types are not recommended for use with LDO regulators since the capacitor tolerance can vary more than ±50% over the
operating temperature range of the device. A 2.2µF
Y5V capacitor could be reduced to 1µF over the full
operating temperature range. This can cause problems for circuit operation and stability. X7R and X5R
dielectrics are much more desirable. The temperature tolerance of X7R dielectric is better than ±15%.
Capacitor area is another contributor to ESR.
Capacitors that are physically large in size will have
a lower ESR when compared to a smaller sized
capacitor of equivalent material and capacitance
value. These larger devices can also improve circuit transient response when compared to an equal
value capacitor in a smaller package size.
Consult capacitor vendor datasheets carefully when
selecting capacitors for use with LDO regulators.
Enable Function
The AAT3201 features an LDO regulator enable /
disable function. This pin (EN) is active high and is
compatible with CMOS logic. To assure the LDO
regulator will switch on, the EN turn-on control level
must be greater than 2.4V. The LDO regulator will
go into the disable shutdown mode when the voltage on the EN pin falls below 0.6V. If the enable
function is not needed in a specific application, it
may be tied to VIN to keep the LDO regulator in a
continuously on state.
Short-Circuit and Thermal Protection
The AAT3201 is protected by both current limit and
over-temperature protection circuitry. The internal
short-circuit current limit is designed to activate
when the output load demand exceeds the maximum rated output. If a short-circuit condition were
10
to continually draw more than the current limit
threshold, the LDO regulator's output voltage would
drop to a level necessary to supply the current
demanded by the load. Under short-circuit or other
over-current operating conditions, the output voltage would drop and the AAT3201's die temperature
would rapidly increase. Once the regulator's power
dissipation capacity has been exceeded and the
internal die temperature reaches approximately
140°C the system thermal protection circuit will
become active. The internal thermal protection circuit will actively turn off the LDO regulator output
pass device to prevent the possibility of over-temperature damage. The LDO regulator output will
remain in a shutdown state until the internal die
temperature falls back below the 140°C trip point.
The interaction between the short-circuit and thermal protection systems allows the LDO regulator to
withstand indefinite short-circuit conditions without
sustaining permanent damage.
No-Load Stability
The AAT3201 is designed to maintain output voltage regulation and stability under operational noload conditions. This is an important characteristic
for applications where the output current may drop
to zero. An output capacitor is required for stability
under no-load operating conditions. Refer to the
Output Capacitor section of this datasheet for recommended typical output capacitor values.
Thermal Considerations and High
Output Current Applications
The AAT3201 is designed to deliver a continuous
output load current of 150mA under normal operating conditions. The limiting characteristic for the
maximum output load safe operating area is essentially package power dissipation and the internal preset thermal limit of the device. 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 LDO regulator is mounted on a printed circuit board utilizing
the minimum recommended footprint and the printed circuit board is 0.062-inch thick FR4 material with
one ounce copper.
3201.2006.01.1.2
AAT3201
150mA OmniPower™ LDO Linear Regulator
At any given ambient temperature (TA), the maximum package power dissipation can be determined by the following equation:
This formula can be solved for VIN to determine the
maximum input voltage.
VIN(MAX) =
-T
T
PD(MAX) = J(MAX) A
θJA
Constants for the AAT3201 are TJ(MAX), the maximum junction temperature for the device which is
125°C, and ΘJA = 150°C/W, the package thermal
resistance. Typically, maximum conditions are calculated at the maximum operating temperature
where TA = 85°C, under normal ambient conditions
TA = 25°C. Given TA = 85°C, the maximum package power dissipation is 267mW. At TA = 25°C, the
maximum package power dissipation is 667mW.
The maximum continuous output current for the
AAT3201 is a function of the package power dissipation and the input-to-output voltage drop across
the LDO regulator. Refer to the following simple
equation:
IOUT(MAX) <
PD(MAX)
VIN - VOUT
For example, if VIN = 5V, VOUT = 2.5V, and TA =
25°C, IOUT(MAX) <267mA. The output short-circuit
protection threshold is set between 150mA and
300mA. If the output load current were to exceed
267mA or if the ambient temperature were to
increase, the internal die temperature will increase.
If the condition remained constant and the short-circuit protection did not activate, there would be a
potential damage hazard to the LDO regulator since
the thermal protection circuit will only activate after a
short-circuit event occurs on the LDO regulator output.
To determine the maximum input voltage for a
given load current, refer to the following equation.
This calculation accounts for the total power dissipation of the LDO regulator, including that caused
by ground current.
PD(MAX) = (VIN - VOUT)IOUT + (VIN × IGND)
3201.2006.01.1.2
PD(MAX) + (VOUT × IOUT)
IOUT + IGND
The following is an example for an AAT3201 set for
a 2.5 volt output:
VOUT
= 2.5V
IOUT
= 150mA
IGND
= 20µA
VIN(MAX) =
667mW + (2.5V × 150mA)
150mA + 20µA
VIN(MAX) = 6.95V
From the discussion above, PD(MAX) was determined to equal 667mW at TA = 25°C.
Thus, the AAT3201 can sustain a constant 2.5V output at a 150mA load current as long as VIN is ≤ 6.95V
at an ambient temperature of 25°C. 5.5V is the maximum input operating voltage for the AAT3201, thus
at 25°C the device would not have any thermal concerns or operational VIN(MAX) limits.
This situation can be different at 85°C. The following is an example for an AAT3201 set for a 2.5 volt
output at 85°C:
VOUT
= 2.5V
IOUT
= 150mA
IGND
= 20µA
VIN(MAX) =
267mW + (2.5V × 150mA)
150mA + 20µA
VIN(MAX) = 4.28V
From the discussion above, PD(MAX) was determined to equal 267mW at TA = 85°C.
11
AAT3201
150mA OmniPower™ LDO Linear Regulator
IGND
= 20µA
IOUT
= 150mA
VIN
= 5.0V
VOUT = 2.5V
PD(MAX)
%DC = 100
(VIN - VOUT)IOUT + (VIN × IGND)
267mW
%DC = 100
(5.0V - 2.5V)150mA + (5.0V × 20µA)
(VOUT = 2.5V @ 25°C)
3.5
Voltage Drop (V)
For example, an application requires VIN = 5.0V
while VOUT = 2.5V at a 150mA load and TA = 85°C.
VIN is greater than 4.28V, which is the maximum
safe continuous input level for VOUT = 2.5V at
150mA for TA = 85°C. To maintain this high input
voltage and output current level, the LDO regulator
must be operated in a duty-cycled mode. Refer to
the following calculation for duty-cycle operation:
Device Duty Cycle vs. VDROP
3
200mA
2.5
2
1.5
1
0.5
0
0
10
20
30
40
50
60
70
80
90
100
Duty Cycle (%)
Device Duty Cycle vs. VDROP
(VOUT = 2.5V @ 50°C)
3.5
Voltage Drop (V)
Higher input-to-output voltage differentials can be
obtained with the AAT3201, while maintaining
device functions in the thermal safe operating area.
To accomplish this, the device thermal resistance
must be reduced by increasing the heat sink area
or by operating the LDO regulator in a duty-cycled
mode.
3
200mA
2.5
150mA
2
1.5
1
0.5
0
0
%DC = 71.2%
10
20
30
40
50
60
70
80
90
100
Duty Cycle (%)
PD(MAX) was assumed to be 267mW.
For a 150mA output current and a 2.5V drop across
the AAT3201 at an ambient temperature of 85°C,
the maximum on-time duty cycle for the device
would be 71.2%.
(VOUT = 2.5V @ 85°C)
3.5
Voltage Drop (V)
The following family of curves shows the safe operating area for duty-cycled operation from ambient
room temperature to the maximum operating level.
Device Duty Cycle vs. VDROP
3
100mA
2.5
2
200mA
1.5
150mA
1
0.5
0
0
10
20
30
40
50
60
70
80
90
100
Duty Cycle (%)
12
3201.2006.01.1.2
AAT3201
150mA OmniPower™ LDO Linear Regulator
High Peak Output Current Applications
Some applications require the LDO regulator to
operate at continuous nominal levels with short
duration, high-current peaks. The duty cycles for
both output current levels must be taken into
account. To do so, first calculate the power dissipation at the nominal continuous level, then factor
in the addition power dissipation due to the short
duration, high-current peaks.
For example, a 2.5V system using an AAT3201IGV2.5-T1 operates at a continuous 100mA load current
level and has short 150mA current peaks. The current peak occurs for 378µs out of a 4.61ms period.
It will be assumed the input voltage is 5.0V.
First, the current duty-cycle percentage must be
calculated:
% Peak Duty Cycle: X/100 = 378ms/4.61ms
% Peak Duty Cycle = 8.2%
The LDO regulator will be under the 100mA load
for 91.8% of the 4.61ms period and have 150mA
peaks occurring for 8.2% of the time. Next, the
continuous nominal power dissipation for the
100mA load should be determined then multiplied
by the duty cycle to conclude the actual power dissipation over time.
PD(MAX)
PD(100mA)
PD(100mA)
= (VIN - VOUT)IOUT + (VIN x IGND)
= (5.0V - 2.5V)100mA + (5.0V x 20µA)
= 250mW
PD(91.8%D/C) = %DC x PD(100mA)
PD(91.8%D/C) = 0.918 x 250mW
PD(91.8%D/C) = 229.5mW
The power dissipation for a 100mA load occurring
for 91.8% of the duty cycle will be 229.5mW. Now
the power dissipation for the remaining 8.2% of the
duty cycle at the 150mA load can be calculated:
3201.2006.01.1.2
= (VIN - VOUT)IOUT + (VIN x IGND)
PD(MAX)
PD(150mA) = (5.0V - 2.5V)150mA + (5.0V x 20µA)
PD(150mA) = 375mW
PD(8.2%D/C) = %DC x PD(150mA)
PD(8.2%D/C) = 0.082 x 375mW
PD(8.2%D/C) = 30.75mW
The power dissipation for a 150mA load occurring
for 8.2% of the duty cycle will be 20.9mW. Finally,
the two power dissipation levels can summed to
determine the total true power dissipation under the
varied load.
PD(total) = PD(100mA) + PD(150mA)
PD(total) = 229.5mW + 30.75mW
PD(total) = 260.25mW
The maximum power dissipation for the AAT3201
operating at an ambient temperature of 85°C is
267mW. The device in this example will have a total
power dissipation of 260.25mW. This is within the
thermal limits for safe operation of the device.
Printed Circuit Board Layout
Recommendations
In order to obtain the maximum performance from
the AAT3201 LDO regulator, careful consideration
should be given to the printed circuit board layout. If
grounding connections are not properly made,
power supply ripple rejection and LDO regulator
transient response can be compromised.
The LDO regulator external capacitors CIN and
COUT should be connected as directly as possible
to the ground pin of the LDO regulator. For maximum performance with the AAT3201, the ground
pin connection should then be made directly back
to the ground or common of the source power supply. If a direct ground return path is not possible
due to printed circuit board layout limitations, the
LDO ground pin should then be connected to the
common ground plane in the application layout.
13
AAT3201
150mA OmniPower™ LDO Linear Regulator
Ordering Information
Output Voltage
Package
Marking1
Part Number (Tape and Reel)2
1.8V
SOT23-5
FDXYY
AAT3201IGV-1.8-T1
2.0V
SOT23-5
AAT3201IGV-2.0-T1
2.3V
SOT23-5
AAT3201IGV-2.3-T1
2.4V
SOT23-5
AAT3201IGV-2.4-T1
2.5V
SOT23-5
FFXYY
AAT3201IGV-2.5-T1
2.7V
SOT23-5
DJXYY
AAT3201IGV-2.7-T1
2.8V
SOT23-5
DKXYY
AAT3201IGV-2.8-T1
2.85V
SOT23-5
3.0V
SOT23-5
DLXYY
AAT3201IGV-3.0-T1
3.3V
SOT23-5
DMXYY
AAT3201IGV-3.3-T1
3.5V
SOT23-5
FNXYY
AAT3201IGV-3.5-T1
AAT3201IGV-2.85-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.
1. XYY = assembly and date code.
2. Sample stock is generally held on all part numbers listed in BOLD.
14
3201.2006.01.1.2
AAT3201
150mA OmniPower™ LDO Linear Regulator
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.
© Advanced Analogic Technologies, Inc.
AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights,
or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice.
Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. AnalogicTech
warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with AnalogicTech’s standard warranty. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed.
Advanced Analogic Technologies, Inc.
830 E. Arques Avenue, Sunnyvale, CA 94085
Phone (408) 737-4600
Fax (408) 737-4611
3201.2006.01.1.2
15