Analogic AAT3242ITP-IG-T1 300ma/150ma dual cmos ldo linear regulator Datasheet

PRODUCT DATASHEET
AAT3242
PowerLinear
300mA/150mA Dual CMOS LDO Linear Regulator
TM
General Description
Features
The AAT3242 is a dual low dropout linear regulator with
Power OK (POK) outputs. Two integrated regulators provide a high power 300mA output and a lower power
150mA output, making this device ideal for use with
microprocessors and DSP cores in portable products.
Two POK pins provide open drain output signals when
their respective regulator output is within regulation.
The AAT3242 has independent input voltage and enable
pins for increased design flexibility. This device features
a very low quiescent current (140μA typical) and low
dropout voltages (typically 200mV and 400mV at the full
output current level), making it ideal for portable applications where extended battery life is critical. The
AAT3242 has complete over-current/short-circuit and
over-temperature protection circuits to guard against
extreme operating conditions.
• High/Low Current Outputs, 300mA/150mA
• Low Dropout:
▪ LDO A: 400mV at 300mA
▪ LDO B: 200mV at 150mA
• High Output Voltage Accuracy: ±1.5%
• High PSRR: 65dB at 1kHz
• 70μA Quiescent Current for Each LDO
• Over-Current/Short-Circuit Protection
• Over-Temperature Protection
• Two POK Outputs
• Independent Power and Enable Inputs
• Uses Low Equivalent Series Resistance (ESR) Ceramic
Capacitors
• 12-Pin TSOPJW and TDFN33 Packages
• -40°C to +85°C Temperature Range
The AAT3242 is available in the space-saving, Pb-free,
12-pin TSOPJW and TDFN33 packages. This device is
capable of operation over the -40°C to +85°C temperature range.
Applications
•
•
•
•
•
•
•
Cellular Phones
Digital Cameras
Handheld Instruments
Microprocessor / DSP Core / I/O Power
Notebook Computers
PDAs and Handheld Computers
Portable Communication Devices
Typical Application
INA
VIN
OUTA
AAT3242
Enable A
ENA
OUTPUT A
100kΩ
POKA
POKA
OUTPUT B
OUTB
INB
100kΩ
POKB
Enable B
3242.2008.08.1.11
ENB
GND
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POKB
2.2μF
2.2μF
1
PRODUCT DATASHEET
AAT3242
PowerLinear
300mA/150mA Dual CMOS LDO Linear Regulator
TM
Pin Descriptions
Pin #
TSOPJW-12
TDFN33-12
Symbol
1
12
ENA
2, 3, 8, 9
4, 10, EP
GND
4
11
POKA
5
9
OUTB
6
7
INB
7
6
ENB
10
5
POKB
11
3
OUTA
12
n/a
1
2, 8
INA
N/C
Function
Enable Regulator A pin; this pin should not be left floating. When pulled low, the PMOS
pass transistor turns off and the device enters shutdown mode, consuming less than
1μA.
Ground connection pins. For the TDFN33 package, The exposed thermal pad (EP)
should be connected to the board ground plane and Pins 4 and 10. The ground plane
should include a large exposed copper pad under the package with vias to the bottom
layer ground plane for thermal dissipation (see package outline).
Power OK pin with open drain output. It is pulled low when the OUTA pin is below the
10% regulation window.
Low current (150mA) regulator output pin; should be decoupled with a 2.2μF or greater
output low-ESR ceramic capacitor.
Input voltage pin for Regulator B; should be decoupled with 1μF or greater capacitor.
Enable Regulator B; this pin should not be left floating. When pulled low, the PMOS pass
transistor turns off and the device enters shutdown mode, consuming less than 1μA.
Power OK pin with open drain output. It is pulled low when the OUTB pin is below the
10% regulation window.
High-current (300mA) regulator output pin; should be decoupled with a 2.2μF or
greater output low-ESR ceramic capacitor.
Input voltage pin for Regulator A; should be decoupled with 1μF or greater capacitor.
Not connected.
Pin Configuration
TSOPJW-12
(Top View)
ENA
GND
GND
POKA
OUTB
INB
2
1
12
2
11
3
10
4
9
5
8
6
7
TDFN33-12
(Top View)
INA
OUTA
POKB
GND
GND
ENB
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INA
N/C
OUTA
GND
POKB
ENB
1
12
2
11
3
4
EP
10
9
5
8
6
7
ENA
POKA
GND
OUTB
N/C
INB
3242.2008.08.1.11
PRODUCT DATASHEET
AAT3242
PowerLinear
TM
300mA/150mA Dual CMOS LDO Linear Regulator
Absolute Maximum Ratings1
Symbol
VIN
VENIN(MAX)
IOUT2
TJ
TLEAD
Description
Input Voltage
Maximum EN to Input Voltage
DC Output Current
Operating Junction Temperature Range
Maximum Soldering Temperature (at leads, 10 sec)
Value
Units
6.0
0.3
PD/(VIN - VO)
-40 to 150
300
V
V
mA
°C
°C
Value
Units
Thermal Information
Symbol
Description
θJA
Thermal Resistance3
PD
Maximum Power Dissipation (TA = 25°C)
TSOPJW-12
TDFN33-12
TSOPJW-124
TDFN33-125
110
50
909
2
°C/W
mW
W
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. Based on long-term current density limitation.
3. Mounted on an FR4 board.
4. Derate 9.1mW/°C above 25°C.
5. Derate 6.25mW/°C above 25°C.
3242.2008.08.1.11
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3
PRODUCT DATASHEET
AAT3242
PowerLinear
TM
300mA/150mA Dual CMOS LDO Linear Regulator
Electrical Characteristics1
VIN = VOUT(NOM) + 1.0V for VOUT options greater than 1.5V. VIN = 2.5V for VOUT ≤ 1.5V. IOUT = 1.0mA, COUT = 2.2μF, CIN =
1.0μF, TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C.
Symbol
Description
Conditions
Min
Typ
Max
Units
400
1.5
2.5
5.5
600
V
mV
0.09
%/V
LDO A; IOUT = 300mA
VOUT
Output Voltage Tolerance
IOUT = 1mA
to 300mA
TA = 25°C
TA = -40 to 85°C
VIN
VDO
ΔVOUT/
VOUT*ΔVIN
Input Voltage
Dropout Voltage2, 3
IOUT = 300mA
Line Regulation4
VIN = VOUT + 1V to 5.0 V
ΔVOUT(Line)
Dynamic Line Regulation
ΔVOUT(Load)
VEN(L)
VEN(H)
VPOK
VPOKHYS
VPOK(LO)
IPOK
IOUT
ISC
IQ
ISD
Dynamic Load Regulation
Enable Threshold Low
Enable Threshold High
Power OK Trip Threshold
Power OK Hysteresis
Power OK Output Voltage Low
POK Output Leakage Current
Output Current
Short-Circuit Current
Ground Current
Shutdown Current
PSRR
Power Supply Rejection Ratio
TSD
THYS
eN
TC
Over-Temperature Shutdown
Threshold
Over-Temperature Shutdown
Hysteresis
Output Noise
Output Voltage Temperature
Coefficient
-1.5
-2.5
VOUT + VDO5
IOUT = 300mA, VIN = VOUT + 1 to
VOUT + 2, TR/TF = 2μs
IOUT = 1mA to 300mA, TR < 5μs
5.0
mV
60
0.6
VOUT Rising, TA = 25°C
ISINK = 1mA
VPOK < 5.5V, VOUT in Regulation
VOUT > 1.2V
VOUT < 0.4V
VIN = 5V, No Load; EN A = VIN
VIN = 5V, EN A = 0V
1kHz
IOUT =10mA
10kHz
1MHz
eNBW = 300Hz to 50kHz
1.5
90
94
1.0
98
0.4
1.0
300
600
70
%
125
1.0
mV
V
V
% of VOUT
% of VOUT
V
μA
mA
mA
μA
μA
65
45
42
dB
145
°C
12
°C
250
μVRMS
22
ppm/°C
1. The AAT3242 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correlation with statistical process controls.
2. VDO is defined as VIN - VOUT when VOUT is 98% of nominal.
3. For VOUT < 2.1V, VDO = 2.5 - VOUT.
4. CIN = 10μF.
5. To calculate minimum input voltage, use the following equation: VIN(MIN) = VOUT(MAX) + VDO(MAX) as long as VIN ≥ 2.5V.
4
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3242.2008.08.1.11
PRODUCT DATASHEET
AAT3242
PowerLinear
TM
300mA/150mA Dual CMOS LDO Linear Regulator
Electrical Characteristics1 (continued)
VIN = VOUT(NOM) + 1.0V for VOUT options greater than 1.5V. VIN = 2.5V for VOUT ≥ 1.5V. IOUT = 1.0mA, COUT = 2.2μF, CIN =
1.0μF, TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C.
Symbol
Description
Conditions
Min
Typ
Max
Units
200
1.5
2.5
5.5
300
V
mV
0.09
%/V
LDO B; IOUT = 150mA
Output Voltage Tolerance
IOUT = 1mA to 150mA
VIN
VDO
ΔVOUT/
VOUT*ΔVIN
Input Voltage
Dropout Voltage2, 3
IOUT = 150mA
Line Regulation4
VIN = VOUT + 1V to 5.0V
ΔVOUT(Line)
Dynamic Line Regulation
ΔVOUT(Load)
VEN(L)
VEN(H)
VPOK
VPOKHYS
VPOK(LO)
IPOK
IOUT
ISC
IQ
Dynamic Load Regulation
Enable Threshold Low
Enable Threshold High
Power OK Trip Threshold
Power OK Hysteresis
Power OK Output Voltage Low
POK Output Leakage Current
Output Current
Short-Circuit Current
Ground Current
PSRR
Power Supply Rejection Ratio
VOUT
TSD
THYS
eN
TC
Over-Temperature Shutdown
Threshold
Over-Temperature Shutdown
Hysteresis
Output Noise
Output Voltage Temperature
Coefficient
TA = 25°C
TA = -40 to 85°C
-1.5
-2.5
VOUT + VDO5
IOUT = 150mA, VIN = VOUT + 1 to VOUT +
2, TR/TF = 2μs
IOUT = 1mA to 150mA, TR <5μs
5.0
mV
60
0.6
VOUT Rising, TA = 25°C
ISINK = 1mA
VPOK < 5.5V, VOUT in Regulation
VOUT > 1.2V
VOUT < 0.4V
VIN = 5V, No Load; EN B = VIN
1kHz
10kHz
IOUT = 10mA
1MHz
eNBW = 300Hz to 50kHz
1.5
90
94
1.0
98
0.4
1.0
150
600
70
65
45
42
%
125
mV
V
V
% of VOUT
% of VOUT
V
μA
mA
mA
μA
dB
145
°C
12
°C
250
μVRMS
22
ppm/°C
1. The AAT3242 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correlation with statistical process controls.
2. VDO is defined as VIN - VOUT when VOUT is 98% of nominal.
3. For VOUT < 2.3V, VDO = 2.5 - VOUT.
4. CIN = 10μF.
5. To calculate minimum input voltage, use the following equation: VIN(MIN) = VOUT(MAX) + VDO(MAX) as long as VIN ≥ 2.5V.
3242.2008.08.1.11
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PRODUCT DATASHEET
AAT3242
PowerLinear
300mA/150mA Dual CMOS LDO Linear Regulator
TM
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA = 25°C.
Dropout Characteristics
Dropout Voltage vs. Temperature
3.20
Output Voltage (V)
Dropout Voltage (mV)
540
IL = 300mA
480
420
360
300
IL = 100mA
IL = 150mA
240
180
120
IOUT = 0mA
3.00
2.80
IOUT = 300mA
IOUT = 150mA
2.60
2.40
2.20
60
IOUT = 10mA
IL = 50mA
0
-40 -30 -20 -10 0
2.00
2.70
10 20 30 40 50 60 70 80 90 100 110 120
2.80
IOUT = 100mA
IOUT = 50mA
2.90
Temperature (°C)
Dropout Voltage vs. Output Current
3.30
400
350
300
85°C
250
200
25°C
150
-40°C
100
80
Ground Current (μA)
Dropout Voltage (mV)
3.20
90
450
70
60
IOUT = 300mA
50
IOUT = 150mA
IOUT = 50mA
40
IOUT = 0mA
30
IOUT = 10mA
20
50
10
0
0
0
50
100
150
200
250
300
2
2.5
3
3.5
4
4.5
Input Voltage (V)
Output Current (mA)
Quiescent Current vs. Temperature
Output Voltage vs. Temperature
1.203
100
90
1.202
80
Output Voltage (V)
Quiescent Current (μA)
3.10
Ground Current vs. Input Voltage
500
70
60
50
40
30
20
10
0
-40 -30 -20 -10
0
10 20 30 40 50 60 70 80 90 100 110 120
1.201
1.200
1.199
1.198
1.197
1.196
-40 -30 -20 -10
Temperature (°C)
6
3.00
Input Voltage (V)
0
10 20
30
40
50 60
70 80
90 100
Temperature (°C)
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3242.2008.08.1.11
PRODUCT DATASHEET
AAT3242
PowerLinear
300mA/150mA Dual CMOS LDO Linear Regulator
TM
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA = 25°C.
Turn-On Time and POK Delay
Line Transient Response
VENABLE (2V/div)
6
3.25
VIN
Input Voltage (V)
5
VOUT (500mV/div)
VPOK (500mV/div)
Time (10μs/div)
3.20
4
3.15
3
3.10
2
3.05
1
3.00
VOUT
0
2.95
-1
2.90
-2
2.85
Time (100μs/div)
Load Transient Response
2.80
300
200
2.75
100
2.70
2.65
IOUT
0
2.60
Output Voltage (V)
400
VOUT
-100
3.00
800
2.90
700
2.80
600
VOUT
2.70
500
2.60
400
2.50
300
2.40
200
2.30
100
IOUT
2.20
0
2.10
-100
Output Current (mA)
2.85
500
Output Current (mA)
Output Voltage (V)
2.90
Load Transient Response 300mA
Time (10μ
μs/div)
Time (100μs/div)
POK Output Response
Over-Current Protection
1200
Output Current (mA)
VIN (2V/div)
VOUT (2V/div)
VPOK (1V/div)
800
600
400
200
0
-200
Time (20ms/div)
Time (200μs/div)
3242.2008.08.1.11
1000
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PRODUCT DATASHEET
AAT3242
PowerLinear
300mA/150mA Dual CMOS LDO Linear Regulator
TM
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA = 25°C.
VEN(H) and V EN(L) vs. VIN
1.250
10
1.225
1.200
1
VEN (V)
Noise Amplitude (mV/rtHz)
Self Noise
0.1
1.175
VEN(H)
1.150
1.125
VEN(L)
1.100
1.075
0.01
0.01
1.050
2.5
0.1
1
10
100
1000
3.0
3.5
4.0
4.5
5.0
5.5
Input Voltage (V)
Frequency (kHz)
8
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3242.2008.08.1.11
PRODUCT DATASHEET
AAT3242
PowerLinear
300mA/150mA Dual CMOS LDO Linear Regulator
TM
Functional Block Diagram
INA
OUTA
Over-Current
Protection
ENA
+
Error
Amplifier
-
Over Temperature
Protection
Voltage
Reference
POKA
+
91%
VREF
OUTB
INB
Over-Current
Protection
Over Temperature
Protection
ENB
+
Error
Amplifier
-
Voltage
Reference
POKB
+
91%
VREF
GND
Functional Description
Applications Information
The AAT3242 is a high performance dual LDO regulator
with two Power OK pins. The first regulator (A) sources
300mA of current, while the second (B) regulator can
deliver 150mA. Each regulator has an integrated Power
OK comparator which indicates when the respective output is out of regulation. The POK pins are open drain
outputs, and they are held low when the respective
regulator is in shutdown mode.
To assure the maximum possible performance is obtained
from the AAT3242, please refer to the following application recommendations.
The device has independent enable pins to shut down
each LDO regulator for power conservation in portable
products. Forcing EN A/B low (<0.6V) powers down the
regulators and draws a maximum of 1.0μA. The AAT3242
has short-circuit and thermal protection in case of
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 current loads.
3242.2008.08.1.11
Input Capacitor
A 1μF or larger capacitor is typically recommended for
CIN in most applications. A CIN capacitor is not required
for basic LDO regulator operation; however, if the
AAT3242 is physically located more than three centimeters from an 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
highest possible power supply ripple rejection.
Ceramic, tantalum, or aluminum electrolytic capacitors
may be selected for CIN. There is no specific capacitor
ESR requirement for CIN; however, for 300mA LDO regu-
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PRODUCT DATASHEET
AAT3242
PowerLinear
TM
300mA/150mA Dual CMOS LDO Linear Regulator
lator 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.
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 AAT3242
has been specifically designed to function with very low
ESR ceramic capacitors. For best performance, ceramic
capacitors are recommended.
Typical output capacitor values for maximum output current conditions range from 1μF to 10μF.
Applications utilizing the exceptionally low output noise
and optimum power supply ripple rejection characteristics of the AAT3242 should use 2.2μF or greater for COUT.
If desired, COUT may be increased without limit. In low
output current applications where output load is less
than 10mA, the minimum value for COUT can be as low as
0.47μF.
Capacitor Characteristics
Ceramic composition capacitors are highly recommended
over all other types of capacitors for use with the
AAT3242. 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 nonpolarized. 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 not prone to incorrect connection damage.
Equivalent Series Resistance
ESR is a very important characteristic to consider when
selecting a capacitor. ESR is the internal series resistance
associated with a capacitor that includes lead resistance,
internal connections, 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.
10
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. 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 temperature; this could cause problems for circuit
operation. 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 which are physically large in size will
have a lower ESR when compared to a smaller sized
capacitor of an equivalent material and capacitance
value. These larger devices can 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 LDO
regulators.
POK Output
The AAT3242 features integrated Power OK comparators
which can be used as an error flag. The POK open drain
output goes low when output voltage is 6% (typ) below
its nominal regulation voltage. Additionally, any time one
of the regulators is in shutdown, the respective POK output is pulled low. Connect a pull-up resistor from POKA
to OUTA, and POKB to OUTB.
Enable Function
The AAT3242 features an LDO regulator enable/disable
function. Each LDO has its own dedicated enable pin.
These pins (EN) are active high and are compatible with
CMOS logic. To assure the LDO regulators will switch on,
ENA/B must be greater than 1.6V. The LDO regulators
will shut down when the voltage on the ENA/B pins falls
below 0.6V. In shutdown, the AAT3242 will consume less
than 1.0μA of current. 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.
When the LDO regulators are in shutdown mode, an
internal 20Ω resistor is connected between VOUT and
GND. This is intended to discharge COUT when the LDO
regulators are disabled. The internal 20Ω has no adverse
effects on device turn-on time.
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3242.2008.08.1.11
PRODUCT DATASHEET
AAT3242
PowerLinear
300mA/150mA Dual CMOS LDO Linear Regulator
TM
Short-Circuit Protection
The AAT3242 contains internal short-circuit protection
that will trigger when the output load current exceeds
the internal threshold limit. Under short-circuit conditions, the output of the LDO regulator will be current
limited until the short-circuit condition is removed from
the output or LDO regulator package power dissipation
exceeds the device thermal limit.
Thermal Protection
The AAT3242 has an internal thermal protection circuit
which will turn on when the device die temperature
exceeds 145°C. The LDO regulator output will remain in
a shutdown state until the internal die temperature falls
back below the 145°C trip point. The combination and
interaction between the short-circuit and thermal protection systems allows the LDO regulators to withstand
indefinite short-circuit conditions without sustaining permanent damage.
No-Load Stability
The AAT3242 is designed to maintain output voltage
regulation and stability under operational no-load conditions. This is an important characteristic for applications
where the output current may drop to zero.
the cathode to VIN and anode to VOUT). The Schottky
diode forward voltage should be less than 0.45V.
Thermal Considerations and
High Output Current Applications
The AAT3242 is designed to deliver continuous output
load currents of 300mA and 150mA under normal operations, and can supply up to 500mA during circuit startup conditions. This is desirable for circuit applications
where there might be a brief high in-rush current during
a power-on event.
The limiting characteristic for the maximum output load
current 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 as stated in the layout
considerations section of this document. At any given
ambient temperature (TA), the maximum package power
dissipation can be determined by the following equation:
PD(MAX) =
Reverse Output-to-Input
Voltage Conditions and Protection
Under normal operating conditions, a parasitic diode
exists between the output and input of the LDO regulator. The input voltage should always remain greater than
the output load voltage maintaining a reverse bias on
the internal parasitic diode. Conditions where VOUT might
exceed VIN should be avoided since this would forward
bias the internal parasitic diode and allow excessive current flow into the VOUT pin, possibly damaging the LDO
regulator. In applications where there is a possibility of
VOUT exceeding VIN for brief amounts of time during normal operation, the use of a larger value CIN capacitor is
highly recommended. A larger value of CIN with respect
to COUT will effect a slower CIN decay rate during shutdown, thus preventing VOUT from exceeding VIN. In applications where there is a greater danger of VOUT exceeding VIN for extended periods of time, it is recommended
to place a Schottky diode across VIN to VOUT (connecting
3242.2008.08.1.11
TJ(MAX) - TA
θJA
Constants for the AAT3242 are TJ(MAX) (the maximum
junction temperature for the device, which is 125°C) and
θJA = 110°C/W (the package thermal resistance).
Typically, maximum conditions are calculated at the
maximum operating temperature of TA = 85°C and
under normal ambient conditions where TA = 25°C.
Given TA = 85°C, the maximum package power dissipation is 364mW. At TA = 25°C, the maximum package
power dissipation is 909mW.
The maximum continuous output current for the AAT3242
is a function of the package power dissipation and the
input-to-output voltage drop across the LDO regulator.
To determine the maximum output current for a given
output voltage, 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 - VOUTA)IOUTA + (VIN x IGND)] + [(VIN - VOUTB)IOUTB + (VIN x IGND)]
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PRODUCT DATASHEET
AAT3242
PowerLinear
TM
300mA/150mA Dual CMOS LDO Linear Regulator
This formula can be solved for IOUTA to determine the
maximum output current for LDOA:
IOUTA(MAX) =
PD(MAX) - (2×VIN × IGND) - (VIN - VOUTB) × IOUTB
VIN - VOUTA
obtained with the AAT3242, while maintaining device
functions within 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.
VOUTA = 2.5V
For example, an application requires VIN = 4.2V while
VOUT = 1.5V at a 500mA load and TA = 25°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:
VOUTB = 1.5V
IGND = 125μA
IOUTB = 150mA
IOUT = 500mA
The following is an example for a 2.5V output in the
TSOPJW package:
VIN
= 4.2V
IGND
= 125μA
VIN
909mW - (2 × 4.2V × 125μA) - (4.2 - 1.5) × 150mA
IOUTA(MAX) =
4.2 - 2.5
IOUTA(MAX) = 296mA
%DC =
100(PD(MAX))
[(VIN - VOUTA)IOUTA + (VIN × IGND)] + [(VIN - VOUTB)IOUTB + (VIN × IGND)]
%DC =
100(909mW)
[(4.2V - 1.5V)500mA + (4.2V × 125μA)] + [(4.2V - 1.5V)200mA + (4.2V × 125μA)]
%DC = 48.10%
From the discussion above, PD(MAX) was determined to
equal 909mW at TA = 25°C.
Therefore, with Regulator B delivering 150mA at 1.5V,
Regulator A can sustain a constant 2.5V output at a
296mA load current at an ambient temperature of 25°C.
Higher input-to-output voltage differentials can be
12
= 4.2V
VOUT = 1.5V
PD(MAX) is assumed to be 909mW.
For a 500mA output current and a 2.7V drop across the
AAT3242 at an ambient temperature of 25°C, the maximum on-time duty cycle for the device would be
48.10%.
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3242.2008.08.1.11
PRODUCT DATASHEET
AAT3242
PowerLinear
300mA/150mA Dual CMOS LDO Linear Regulator
TM
Ordering Information
Voltage
Package
LDO A
LDO B
Marking1
Part Number (Tape and Reel)2
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TSOPJW-12
TDFN33-12
3.3V
3.3V
3.0V
3.0V
3.0V
3.0V
2.9V
2.8V
2.8V
2.8V
2.8V
2.8V
2.8V
2.7V
2.6V
2.5V
1.8V
1.8V
1.8V
1.8V
2.5V
1.8V
2.85V
2.5V
1.8V
1.5V
1.5V
3.0V
2.8V
2.6V
2.5V
1.9V
1.5V
2.7V
1.8V
1.8V
1.5V
2.7V
2.8V
2.8V
LSXYY
PAXYY
LPXYY
LJXYY
LHXYY
NTXYY
MOXYY
LVXYY
LDXYY
LQXYY
LLXYY
LRXYY
MCXYY
LOXYY
MJXYY
SGXYY
AAT3242ITP-WN-T1
AAT3242ITP-WI-T1
AAT3242ITP-TR-T1
AAT3242ITP-TN-T1
AAT3242ITP-TI-T1
AAT3242ITP-TG-T1
AAT3242ITP-SG-T1
AAT3242ITP-QT-T1
AAT3242ITP-QQ-T1
AAT3242ITP-QO-T1
AAT3242ITP-QN-T1
AAT3242ITP-QY-T1
AAT3242ITP-QG-T1
AAT3242ITP-PP-T1
AAT3242ITP-OI-T1
AAT3242ITP-IN-T1
AAT3242ITP-IG-T1
AAT3242ITP-IP-T1
AAT3242ITP-IQ-T1
AAT3242IWP-IQ-T1
PZXYY
RRXYY
5ZXYY
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/about/quality.aspx.
Legend
Voltage
Code
1.5
1.8
1.9
2.5
2.6
2.7
2.8
2.85
2.9
3.0
3.3
G
I
Y
N
O
P
Q
R
S
T
W
1. XYY = assembly and date code.
2. Sample stock is generally held on part numbers listed in BOLD.
3242.2008.08.1.11
www.analogictech.com
13
PRODUCT DATASHEET
AAT3242
PowerLinear
300mA/150mA Dual CMOS LDO Linear Regulator
TM
Package Information
TSOPJW-12
2.85 ± 0.20
2.40 ± 0.10
0.20 + 0.10
- 0.05
0.50 BSC 0.50 BSC 0.50 BSC 0.50 BSC 0.50 BSC
7° NOM
0.04 REF
0.055 ± 0.045
0.15 ± 0.05
+ 0.10
1.00 - 0.065
0.9625 ± 0.0375
3.00 ± 0.10
4° ± 4°
0.45 ± 0.15
0.010
2.75 ± 0.25
All dimensions in millimeters.
14
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3242.2008.08.1.11
PRODUCT DATASHEET
AAT3242
PowerLinear
300mA/150mA Dual CMOS LDO Linear Regulator
TM
TDFN33-12
Index Area
0.43 ± 0.05
Detail "A"
C0.3
0.45 ± 0.05
2.40 ± 0.05
3.00 ± 0.05
0.1 REF
3.00 ± 0.05
1.70 ± 0.05
Top View
Bottom View
0.23 ± 0.05
Pin 1 Indicator
(optional)
0.05 ± 0.05
0.23 ± 0.05
0.75 ± 0.05
Detail "A"
Side View
1. The leadless package family, which includes QFN, TQFN, DFN, TDFN, and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing
process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection.
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Phone (408) 737-4600
Fax (408) 737-4611
© 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
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design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to
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3242.2008.08.1.11
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15
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