Analogic AAT2503 Adjustable 3-channel regulator Datasheet

AAT2503
Adjustable 3-Channel Regulator
General Description
Features
The AAT2503 is a three-channel regulator consisting of a step-down converter with an input voltage
range of 2.7V to 5.5V plus two low dropout (LDO)
linear regulators.
•
The step-down converter optimizes power efficiency throughout the load range. Pulling the MODE/
SYNC pin high enables "PWM Only" mode, maintaining constant frequency and low output ripple
across the operating range. Alternatively, the converter may be synchronized to an external clock
input to the MODE/SYNC pin. The step-down converter delivers up to 800mA of output current, while
consuming 30µA of typical no load quiescent current. The switching frequency is 2MHz, minimizing
the size of external components.
•
•
•
•
•
•
•
The two LDOs (LDOA/LDOB) have independent
inputs and are capable of delivering up to 150mA
each. A Power-OK (POK) function provides an
open drain output signal when LDOA is within regulation. Both LDOs feature low quiescent current
and a low dropout voltage. The output voltages for
both LDOs are adjustable to as low as 0.6V. The
linear regulators have independent Enable pins.
SystemPower™
800mA Step-Down Converter
— VIN Range: 2.7V to 5.5V
— VOUT Range: 0.9V to VIN
— High Efficiency
— 2MHz Switching Frequency
Two 150mA Low Dropout Regulators
— VOUT Range: 0.6V to VIN
— High Output Accuracy: ±1.5%
85µA of Total IQ
Independent Enable Pins
Integrated Power MOSFETs
Over-Temperature and Current Limit
Protection
QFN34-20 Package
-40°C to +85°C Temperature Range
Applications
•
•
•
•
•
The AAT2503 is available in a Pb-free 3x4mm
QFN34-20 package and is rated over the -40°C to
+85°C temperature range.
Cellular Phones
Digital Cameras
Handheld Instruments
Microprocessor/DSP Core/IO Power
PDAs and Handheld Computers
Typical Application
L1
LX
AAT2503
VIN
VIN
VLDOA
VLDOB
VP
MODE/SYNC
EN
2503.2007.04.1.1
R1
OUTA
R3
100kΩ
POK
R4
OUTA
C2
10μF
POK
FBA
OUTB
OUTB
R5
FBB
ENA
ENB
VOUT (Buck)
FB
R8
C6
2.2μF
R7
C5
2.2μF
R2
PGND
AGND
1
AAT2503
Adjustable 3-Channel Regulator
Pin Descriptions
Pin #
Symbol
1
FBB
2
ENA
3
ENB
4
MODE/SYNC
5
FB
6
7
AGND
PGND
8, 9
LX
10
11, 12
13
VP
N/C
VIN
14
EN
15
POK
16
FBA
17
18
19
20
EP
OUTA
VLDOA
VLDOB
OUTB
2
Function
Feedback input pin for LDOB. This pin is connected to OUTB via an external resistor. It is
used to see the output of LDOB to regulate to the desired value via an external resistor
divider. For fixed versions, short FBB to OUTB.
Enable pin for LDOA. When connected low, LDOA is disabled and consumes less than
1µA of current. When connected high, normal operation.
Enable pin for LDOB. When connected low, LDOB is disabled and consumes less than
1µA of current. When connected high, normal operation.
Connect to ground for PWM/PFM mode and optimized efficiency throughout the load range.
Connect high for low noise PWM operation under all operating conditions. Connect to an
external clock for synchronization (PWM only).
Feedback input pin for the step-down converter. This pin is connected to the converter output via an external resistor. It is used to see the output of the converter to regulate to the
desired value via an external resistor divider.
Ground connection pin.
Main power ground return pin for the step-down converter. Connect to the output and input
capacitor return.
Connect inductor to this pin. Switching node internally connected to the drain of both highand low-side MOSFETs.
Input supply voltage for the converter. Must be closely decoupled.
Not connected.
Bias supply. Supply power for the internal circuitry. Connect to input power via low pass filter
with decoupling to AGND.
Enable for the step-down converter. A logic low disables the converter and it consumes less
than 1µA of current. A logic high enables normal operation.
Power-OK pin with open drain output. It is pulled low when the OUTA pin is outside the regulation window of ±10%. Place a pull-up resistor between POK and OUTA.
Feedback input pin for LDOA. This pin is connected to OUTA via an external resistor. It is
used to see the output of LDOA to regulate to the desired value via an external resistor
divider. For fixed versions, short FBA to OUTA.
LDOA output pin; should be closely decoupled with a low-ESR ceramic capacitor.
Input voltage pin for linear regulator A; should be closely decoupled.
Input voltage pin for linear regulator B; should be closely decoupled.
LDOB output pin; should be closely decoupled with a low-ESR ceramic capacitor.
Exposed paddle; connect to ground directly beneath the package.
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
Pin Configuration
QFN34-20
(Top View)
OUTA
VLDOA
VLDOB
OUTB
17
18
19
20
FBB
ENA
ENB
MODE/SYNC
FB
AGND
1
16
2
15
3
14
4
13
5
12
6
11
FBA
POK
EN
VIN
N/C
N/C
9
10
8
7
VP
LX
LX
PGND
Absolute Maximum Ratings1
Symbol
VP, VIN, VLDO
VLX
VFB
VN
TJ
TLEAD
Description
Input Voltage and Bias Power to GND
LX to GND
FB to GND
EN, MODE/SYNC to GND
Operating Junction Temperature Range
Maximum Soldering Temperature (at leads, 10 sec)
Value
Units
6.0
-0.3 to VP + 0.3
-0.3 to VP + 0.3
-0.3 to 6.0
-40 to 150
300
V
V
V
V
°C
°C
Value
Units
2.0
50
W
°C/W
Thermal Information
Symbol
PD
θJA
Description
Maximum Power Dissipation (TA = 25°C)
Thermal Resistance2
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 an FR4 board.
2503.2007.04.1.1
3
AAT2503
Adjustable 3-Channel Regulator
Electrical Characteristics1
VIN = 3.6V; TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C.
Symbol
Description
Bias Power Supply
IQ
Quiescent Current
ISHDN
Shutdown Current
LDOA, LDOB; IOUT = 150mA
VLDO
Input Voltage
VOUT
VFB
VDO
ΔVOUT/
VOUT*ΔVIN
VEN(L)
VEN(H)
IOUT
ISC
ISHT
TSD
THYS
LDOA; IOUT
VPOK
VPOKHYS
VPOK(LO)
IPOK
Output Voltage Tolerance
Conditions
Units
85
µA
µA
ENA = ENB = EN = VIN; ILOAD = 0
ENA = ENB = EN = GND
IOUT = 1mA
to 150mA
TA = 25°C
TA = -40°C to +85°C
Feedback Voltage
Dropout Voltage2
IOUT = 150mA
Line Regulation3
VIN = VOUT + 1 to 5.0V
Enable Threshold Low
Enable Threshold High
Output Current
Short-Circuit Current
Shutdown Current
Over-Temperature Shutdown
Threshold
Over-Temperature Shutdown
Hysteresis
= 150mA
Power-OK Trip Threshold
Power-OK Hysteresis
Power-OK Output Voltage Low
Power-OK Output Leakage Current
Min Typ Max
145
1.0
2.8
5.5
-1.5
1.5
-2.5
2.5
0.593 0.6 0.607
150
V
mV
0.09
%/V
0.6
V
V
mA
mA
µA
1.4
150
VOUT < 0.4V
VIN = 5V
VOUT Rising, TA = 25°C
ISINK = 1mA
VPOK <5.5V, VOUT in Regulation
300
1.0
90
V
%
140
°C
15
°C
94
1.0
98
0.4
1.0
% of VOUT
% of VOUT
V
µA
1. The AAT2503 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. CIN = 10µF.
4
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
Electrical Characteristics (continued)1
VIN = 3.6V; TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C.
Symbol
Description
Conditions
Step-Down Converter; IOUT = 800mA
VIN
Input Voltage
UVLO
Under-Voltage Lockout Voltage
VOUT
Output Voltage Tolerance
VOUT
VFB
ISHDN
VOUT Programmable Range
Feedback Threshold Voltage
Shutdown Current
LX Leakage Current
Feedback Leakage
Current Limit
High Side Switch On Resistance
Low Side Switch On Resistance
Load Regulation
ILX_LEAK
IFB
ILIM
RDS(ON)H
RDS(ON)L
ΔVOUT/VOUT
ΔVOUT/
VOUT*ΔVIN
FOSC
TSD
THYS
VEN(L)
VEN(H)
IEN
Max
Units
Oscillator Frequency
Over-Temperature Shutdown
Threshold
Over-Temperature Shutdown
Hysteresis
Enable Threshold Low
Enable Threshold High
EN Input Leakage
Enable Threshold Low
VMODE/SYNC(H)
Enable Threshold High
Input Low Current
Typ
5.5
1.8
V
V
mV
V
-3.0
3.0
%
0.9
0.891
VIN
0.909
1.0
1.0
0.2
1.2
400
300
0.5
V
V
µA
µA
µA
A
mΩ
mΩ
%
0.2
%/V
2.7
VIN Rising
Hysteresis
VIN Falling
IOUT = 0 to 800mA;
VIN = 2.7V to 5.5V
250
1.5
0.9
EN = GND
VIN = 5.5, VLX = 0 to VIN
VFB = 1.0V
ILOAD = 0 to 800mA
Line Regulation
VMODE/SYNC(L)
IMODE/SYNC
Min
1.6
2.0
2.4
140
°C
15
°C
0.6
VEN = 5V, VIN = 5V
1.4
-1.0
VIN ×
0.7
-1.0
MHz
1.0
VIN ×
0.4
V
V
µA
V
V
1.0
µA
1. The AAT2503 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.
2503.2007.04.1.1
5
AAT2503
Adjustable 3-Channel Regulator
Typical Characteristics—Step-Down Converter
Efficiency vs. Output Current
Efficiency vs. Output Current
(VOUT = 1.8V; L = 2.2µH)
100
100
90
90
80
80
Efficiency (%)
Efficiency (%)
(VOUT = 2.5V; L = 3.3µH)
VIN = 3.3V
70
60
VIN = 3.6V
50
PWM Only
Mode
40
VIN = 4.2V
30
VIN = 3.6V
70
VIN = 2.7V
60
50
PWM Only
Mode
40
VIN = 4.2V
30
20
20
10
10
0
0
0
1
10
100
0
1000
1
Efficiency vs. Output Current
Switching Frequency vs. Temperature
2.4
80
2.3
70
Frequency (MHz)
Efficiency (%)
(VIN = 3.6V; IOUT = 800mA)
90
VIN = 2.7V
60
50
VIN = 3.6V
40
PWM Only
Mode
VIN = 4.2V
20
VOUT = 0.9V
2.2
2.1
VOUT = 1.8V
2.0
1.9
1.8
VOUT = 2.5V
1.7
1.6
0
0
1
10
100
1000
1.5
-40
-20
0
20
40
60
80
Load Regulation
Soft Start
(VOUT = 1.8V; VMODE/SYNC = VIN; L = 2.2µH)
(VIN = 3.6V; VOUT = 1.8V; IOUT = 800mA)
6.0
0.9
4.0
0.6
VIN = 4.2V
0.0
-0.3
VIN = 3.3V VIN = 3.6V
-0.6
-0.9
ENABLE
1.8V
2.0
0.0
VOUT
0V
1.0
0.5
IINDUCTOR
Inductor Current
(Bottom) (A)
ENABLE and VOUT
(Top and Middle) (V)
1.2
0.3
100
Temperature (°°C)
Output Current (mA)
0.0
-1.2
-0.5
0
1
10
Output Current (mA)
6
1000
Output Current (mA)
10
Accuracy (%)
100
Output Current (mA)
(VOUT = 0.9V; L = 1µH)
30
10
100
1000
Time (100µs/div)
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
Typical Characteristics—Step-Down Converter
Turn Off
Line Regulation
(VIN = 3.6V; VOUT = 1.8V; IOUT = 800mA)
(VOUT = 1.8V; VMODE/SYNC = VIN)
1.2
6.0
ENABLE
2.0
0.0
VOUT (1V/div)
1.8V
1.0
0V
IINDUCTOR
0.5
Accuracy (%)
0.9
Inductor Current
(Bottom) (A)
ENABLE and VOUT
(Top and Middle) (V)
4.0
0.6
0.3
IL = 800mA
0.0
-0.3
IL = 10mA
0.0
-0.9
-0.5
-1.2
2.7
3.1
3.5
Time (100µs/div)
4.3
4.7
5.1
5.5
No Load Quiescent Current vs. VIN
Line Regulation
(VOUT = 1.8V; L = 2.2µH)
1.2
Quiescent Current (µA)
65
0.9
Accuracy (%)
3.9
Input Voltage (V)
(VOUT = 0.9V; VMODE/SYNC = VIN)
0.6
IL = 800mA
0.3
0.0
-0.3
IL = 650mA
-0.6
-0.9
-1.2
60
55
TA = 85°C
50
45
TA = 25°C
40
35
TA = -40°C
30
25
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
2.7
3.1
3.5
Input Voltage (V)
3.9
4.3
4.7
5.1
5.5
Input Voltage (V)
No Load Quiescent Current vs. VIN
Output Voltage Error vs. Temperature
(VOUT = 0.9V; L = 1µH)
(VIN = 3.6V; VOUT = 0.9V; IOUT = 800mA)
50
2.0
Output Voltage Error (%)
Quiescent Current (µA)
IL = 100mA
-0.6
45
TA = 85°C
40
35
TA = 25°C
30
TA = -40°C
25
20
2.7
3.1
3.5
3.9
4.3
Input Voltage (V)
2503.2007.04.1.1
4.7
5.1
5.5
1.5
VIN = 1.8V
VIN = 2.5V
1.0
0.5
0.0
-0.5
-1.0
VOUT = 0.9V
-1.5
-2.0
-40
-20
0
20
40
60
80
100
Temperature (°°C)
7
AAT2503
Adjustable 3-Channel Regulator
Line Transient
Load Transient
(VOUT = 1.8V; IOUT = 800mA; VIN = 3.6V to 4.2V)
(VIN = 3.6V; VOUT = 1.8V; IOUT = 300mA to 650mA)
2.2
2.4
2.0
4.0
2.3
3.5
2.2
3.0
2.1
2.5
2.0
2.0
1.9
1.5
1.8
1.0
1.7
Output Voltage
(top) (V)
2.5
4.5
1.8
1.6
VOUT
IOUT
300mA
1.2
0.6
1.0
0.5
1.6
0.8
0.0
1.5
0.6
IINDUCTOR
Light Load Output Ripple
Heavy Load Output Ripple
(VIN = 3.6V; VOUT = 1.8V; IOUT = 800mA)
0
0.8
-10
0.6
-20
0.4
-30
IINDUCTOR
-40
0.0
-50
-0.2
-60
1.6
Inductor Current
(Bottom) (A)
Inductor Current
(Bottom) (A)
1.0
1.8
20
10
VOUT
1.4
0
1.2
-10
1.0
-20
0.8
-30
0.6
0.4
-40
IINDUCTOR
-50
0.2
-60
Output Voltage (AC coupled)
(Top) (mV)
10
Output Voltage (AC coupled)
(Top) (mV)
20
VOUT
Time (10µs/div)
8
Time (20µs/div)
(VIN = 2.7V; VOUT = 1.8V; IOUT = 1mA)
1.4
0.2
0.3
0.0
Time (20µs/div)
1.2
650mA
1.4
Load and Inductor Current
(Bottom) (A)
5.0
Output Voltage
(bottom) (V)
Input Voltage
(top) (V)
Typical Characteristics—Step-Down Converter
Time (200ms/div)
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
Typical Characteristics—LDO Regulator
Dropout Voltage vs. Temperature
Dropout Voltage vs. Output Current
(VOUT = 2.8V)
(VOUT = 2.8V)
100
150mA
100
80
Dropout Voltage (mV)
Dropout Voltage (mV)
120
100mA
60
50mA
40
20
90
85°C
80
70
25°C
60
50
40
30
-40°C
20
10
0
0
-40
-20
0
20
40
60
80
100
0
120
20
40
60
Temperature (°°C)
80
100
120
140
160
Output Current (mA)
Dropout Characteristics
DC Regulation
(VIN = 3.6V; VOUT = 1.2V)
2.5
3.0
1mA
DC Regulation (%)
Output Voltage (V)
2.0
10mA
2.9
2.8
150mA
100mA
2.7
2.6
50mA
2.5
1.5
1.0
0.5
IOUT = 50mA
0.0
-0.5
IOUT = 1mA
-1.0
IOUT = 100mA
-1.5
-2.0
IOUT = 150mA
-2.5
2.4
2.7
2.8
2.9
3.0
3.1
-40
3.2
-20
0
DC Regulation
(VIN = 3.6V; VOUT = 2.8V)
2.5
2.0
DC Regulation (%)
DC Regulation (%)
DC Regulation
2.0
1.5
1.0
IOUT = 50mA
0.5
IOUT = 1mA
0.0
-0.5
IOUT = 150mA
IOUT = 100mA
-2.0
-2.5
-40
60
(VIN = 3.6V; VOUT = 1.8V)
2.5
-1.5
40
80
100
Temperature (°°C)
Input Voltage (V)
-1.0
20
1.5
1.0
IOUT = 50mA
0.5
0.0
-0.5
IOUT = 1mA
-1.0
IOUT = 100mA
-1.5
IOUT = 150mA
-2.0
-2.5
-20
0
20
40
60
Temperature (°°C)
2503.2007.04.1.1
80
100
-40
-20
0
20
40
60
80
100
Temperature (°°C)
9
AAT2503
Adjustable 3-Channel Regulator
Typical Characteristics—LDO Regulator
Quiescent Current vs. Input Voltage
Turn-On Response Time
(VOUT = 2.8V)
(VIN = 3.6V; VOUT = 1.8V; IOUT = 150mA)
IOUT = 150mA
IOUT = 100mA
ENABLE
(Top ) (V)
31
27
IOUT = 50mA
23
IOUT = 10mA
IOUT = 0mA
19
15
2.7
3.1
3.5
3.9
4.3
4.7
5.1
6
7
4
6
2
5
0
4
-2
3
-4
2
-6
1
-8
0
-10
-1
5.5
Time (10µs/div)
Input Voltage (V)
Turn-Off Response Time
Load Transient
(VIN = 3.6V; VOUT = 1.8V; IOUT = 150mA)
(VIN = 3.6V; VOUT = 1.8V; IOUT = 1mA to 100mA)
2.2
0.7
6
2.0
0.6
2
5
1.8
0.5
0
4
1.6
0.4
-2
3
1.4
0.3
-4
2
1.2
0.2
-6
1
1.0
0.1
-8
0
0.8
0.0
-10
-1
0.6
-0.1
Time (50µs/div)
Output Voltage
(top) (V)
7
4
Output Current
(Bottom) (A)
6
Output Voltage
(Bottom) (V)
ENABLE
(Top ) (V)
Output Voltage
(Bottom) (V)
Quiescent Current (µA)
35
Time (200µs/div)
Load Transient
2.2
0.7
2.0
0.6
1.8
0.5
1.6
0.4
1.4
0.3
1.2
0.2
1.0
0.1
0.8
0.0
0.6
-0.1
Output Current
(Bottom) (A)
Output Voltage
(Top) (V)
(VIN = 3.6V; VOUT = 1.8V; IOUT = 50mA to 100mA)
Time (50µs/div)
10
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
Typical Characteristics—LDO Regulator
Line Transient
Line Transient
(VOUT = 1.8V; IOUT = 100mA; VIN = 3.6V to 4.2V)
(VOUT = 1.8V; IOUT = 150mA; VIN = 3.6V to 4.2V)
4.5
2.4
4.0
2.3
3.5
2.2
3.0
2.1
2.5
2.0
2.0
1.9
VIN
2.3
3.0
2.2
2.5
2.1
2.0
2.0
1.5
1.9
1.0
1.8
0.5
VOUT
0.0
2.4
VIN
1.8
1.5
1.0
VOUT
1.7
1.7
0.5
1.6
1.6
0.0
1.5
Time (100µs/div)
Time (100µs/div)
Load Regulation
Line Regulation
(VOUT = 1.2V)
(VOUT = 1.2V)
2.0
2.0
1.5
1.5
1.0
10mA
1mA
0.5
0.0
50mA
-0.5
150mA
100mA
-1.0
Output Error (%)
Output Error (%)
Output Voltage
(bottom) (V)
3.5
Input Voltage
(top) (V)
5.0
2.5
Output Voltage
(bottom) (V)
2.6
4.5
4.0
Input Voltage
(top) (V)
2.5
5.0
1.0
VIN = 2.7V
0.5
VIN = 3.6V
0.0
-0.5
VIN = 5.5V
-1.0
VIN = 4.2V
-1.5
-1.5
-2.0
-2.0
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
Input Voltage (V)
0
1
10
100
1000
Output Current (mA)
Load Regulation
(VOUT = 2.8V)
2.0
Output Error (%)
1.5
1.0
VIN = 3.3V
0.5
VIN = 3.6V
0.0
-0.5
VIN = 5.5V
-1.0
VIN = 4.2V
-1.5
-2.0
0
1
10
100
1000
Output Current (mA)
2503.2007.04.1.1
11
AAT2503
Adjustable 3-Channel Regulator
Functional Block Diagram
FB
Voltage
Reference
VP
VIN
DH
Err.
Amp.
MODE/SYNC
LX
Logic
Control
Logic
EN
DL
PGND
OUTA
VLDOA
Over-Current
Protection
ENB
Err.
Amp.
VLDOB
Err.
Amp.
ENA
Over-Current
Protection
Voltage
Reference
FBA
94%
VREF
POK
OUTB
FBB
Functional Description
The AAT2503 is a high performance power management IC comprised of a step-down converter
and two linear regulators. The step-down converter operates in both fixed and variable frequency
modes for high efficiency performance. The switching frequency is 2MHz, minimizing the size of the
inductor. The converter requires only three external
components (CIN, COUT, and L). The LDOs can
deliver up to 150mA each. Each regulator has
independent input voltage and enable pins and
operates with ceramic capacitors.
Switch-Mode Step-Down Converter
The switching regulator is a monolithic step-down
converter operating with input voltage range of 2.7V
to 5.5V. Power devices are sized for 800mA current
capability and achieve over 95% efficiency. PFM
12
AGND
operation maintains high efficiency under light load
conditions (typically <50mA). The MODE/SYNC pin
allows an optional "PWM Only" mode. This maintains constant frequency and low output ripple
across all load conditions. Alternatively, the IC can
be synchronized to an external clock via the
MODE/SYNC input. External synchronization is
maintained between 1MHz and 3MHz. It consumes
30µA of typical no load quiescent current, making it
also ideal for light load applications. The oscillator
operates at 2MHz, minimizing the cost and size of
external components.
A logic low on the EN pin shuts the converter down
and makes it consume less than 1µA of current.
Soft start increases the inductor current limit point
in discrete steps when the input voltage or enable
input is applied. It limits the current surge seen at
the input and eliminates output voltage overshoot.
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
For overload conditions, the peak input current is
limited. As load impedance decreases and the output voltage falls closer to zero, more power gets
internally dissipated, raising the device temperature. Thermal protection completely disables
switching when internal dissipation becomes
excessive, protecting the device from damage.
The junction over-temperature threshold is 140°C
with 15°C of hysteresis.
Control Loop
The AAT2503 includes a peak current mode stepdown converter. The current through the P-channel
MOSFET (high side) is sensed for current loop
control, as well as short-circuit and overload protection. A fixed slope compensation signal is added
to the sensed current to maintain stability for duty
cycles greater than 50%. The peak current mode
loop appears as a voltage-programmed current
source in parallel with the output capacitor.
The output of the voltage error amplifier programs
the current mode loop for the necessary peak
switch current to force a constant output voltage for
all load and line conditions. Internal loop compensation terminates the transconductance voltage
error amplifier output. For fixed voltage versions,
the error amplifier reference voltage is internally set
to program the converter output voltage. For the
adjustable output, the error amplifier reference is
fixed at 0.9V.
Soft Start / Enable
Soft start limits the current surge seen at the input
and eliminates output voltage overshoot in the
step-down converter.
2503.2007.04.1.1
The step-down converter and the two LDOs have
independent enable pins. When pulled low, the
enable input forces the LDO into shutdown mode
and forces the step-down converter into a lowpower, non-switching state. The input current during shutdown is less than 1µA.
Linear Regulators
The two linear regulators are high performance
LDOs where each LDO can source up to 150mA of
current. For added flexibility, both regulators have
independent input voltages operating from 2.8V to
5.5V. An external feedback pin for each LDO allows
programming the output voltage from VIN to 0.6V.
The regulators have short-circuit and thermal protection in case of adverse operating conditions.
LDOA features an integrated Power-OK comparator which indicates when the output is out of regulation. The POK is an open drain output and it is
held low when the AAT2503 is in shutdown mode.
Under-Voltage Lockout
Internal bias of all circuits is controlled via the VIN
pin. Under-voltage lockout guarantees sufficient
VIN bias and proper operation of all internal circuits
prior to activation.
Over-Temperature Protection
Thermal protection completely disables switching
when internal dissipation becomes excessive. The
junction over-temperature threshold is 140°C with
15°C of hysteresis. Once an over-temperature or
over-current fault conditions is removed, the output
voltage automatically recovers.
13
AAT2503
Adjustable 3-Channel Regulator
Applications Information
Step-Down Converter Inductor Selection
The step-down converter uses peak current mode
control with slope compensation to maintain stability
for duty cycles greater than 50%. The output inductor value must be selected so the inductor current
down slope meets the internal slope compensation
requirements. The internal slope compensation for
the AAT2503 step-down converter is 0.51A/µsec.
This equates to a slope compensation that is 75% of
the inductor current down slope for a 1.5V output
and 2.2µH inductor.
the acceptable input ripple level (VPP) and solve for
CIN. The calculated value varies with input voltage
and is a maximum when VIN is double the output
voltage.
CIN =
CIN(MIN) =
Manufacturer's specifications list both the inductor
DC current rating, which is a thermal limitation, and
the peak current rating, which is determined by the
saturation characteristics. The inductor should not
show any appreciable saturation under normal load
conditions. Some inductors may meet the peak and
average current ratings yet result in excessive losses due to a high DCR. Always consider the losses
associated with the DCR and its effect on the total
converter efficiency when selecting an inductor.
The 2.2µH CDRH2D14 series Sumida inductor has
a 94mΩ DCR and a 1.5A DC current rating. At full
800mA load, the inductor DC loss is 17mW which
gives a 2.8% loss in efficiency for a 800mA, 1.8V
output.
1
⎛ VPP
⎞
- ESR · 4 · FS
⎝ IO
⎠
Always examine the ceramic capacitor DC voltage
coefficient characteristics when selecting the proper value. For example, the capacitance of a 10µF,
6.3V, X5R ceramic capacitor with 5.0V DC applied
is actually about 6µF.
The maximum input capacitor RMS current is:
IRMS = IO ·
VO ⎛
V ⎞
· 1- O
VIN ⎝
VIN ⎠
The input capacitor RMS ripple current varies with
the input and output voltage and will always be less
than or equal to half of the total DC load current.
Input Capacitor
Select a 4.7µF to 10µF X7R or X5R ceramic capacitor for the input of the step-down converter. To estimate the required input capacitor size, determine
0.9V Adjustable With
External Feedback
⎛ VPP
⎞
- ESR · FS
⎝ IO
⎠
VO ⎛
V ⎞
1
· 1 - O = for VIN = 2 · VO
VIN ⎝
VIN ⎠
4
0.75 ⋅ VO 0.75 ⋅ 1.5V
A
m=
=
= 0.51
L
2.2μH
μsec
Configuration
VO ⎛
V ⎞
· 1- O
VIN ⎝
VIN ⎠
VO ⎛
V ⎞
· 1- O =
VIN ⎝
VIN ⎠
D · (1 - D) =
Output Voltage
Inductor
1V, 1.2V
1.5µH
1.5V, 1.8V
2.2µH
2.5V, 3.3V
3.3µH
0.52 =
1
2
Table 1: Inductor Values.
14
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
for VIN = 2 x VO:
IRMS(MAX) =
IO
2
VO ⎛
V ⎞
· 1- O
VIN ⎝
VIN ⎠
The term
appears in both the input
voltage ripple and input capacitor RMS current
equations and is a maximum when VO is twice VIN.
This is why the input voltage ripple and the input
capacitor RMS current ripple are a maximum at
50% duty cycle.
The input capacitor provides a low impedance loop
for the edges of pulsed current drawn by the
AAT2503. Low ESR/ESL X7R and X5R ceramic
capacitors are ideal for this function. To minimize
stray inductance, the capacitor should be placed as
closely as possible to the IC. This keeps the high
frequency content of the input current localized,
minimizing EMI and input voltage ripple.
A laboratory test set-up typically consists of two
long wires running from the bench power supply to
the evaluation board input voltage pins. The inductance of these wires, along with the low-ESR
ceramic input capacitor, can create a high Q network that may affect converter performance. This
problem often becomes apparent in the form of
excessive ringing in the output voltage during load
transients. Errors in the loop phase and gain measurements can also result.
Since the inductance of a short PCB trace feeding
the input voltage is significantly lower than the
power leads from the bench power supply, most
applications do not exhibit this problem.
cally provides sufficient bulk capacitance to stabilize the output during large load transitions and has
the ESR and ESL characteristics necessary for low
output ripple.
The output voltage droop due to a load transient is
dominated by the capacitance of the ceramic output capacitor. During a step increase in load current, the ceramic output capacitor alone supplies
the load current until the loop responds. Within two
or three switching cycles, the loop responds and
the inductor current increases to match the load
current demand. The relationship of the output voltage droop during the three switching cycles to the
output capacitance can be estimated by:
COUT =
3 · ΔILOAD
VDROOP · FS
Once the average inductor current increases to the
DC load level, the output voltage recovers. The
above equation establishes a limit on the minimum
value for the output capacitor with respect to load
transients.
The internal voltage loop compensation also limits
the minimum output capacitor value to 4.7µF. This
is due to its effect on the loop crossover frequency
(bandwidth), phase margin, and gain margin.
Increased output capacitance will reduce the
crossover frequency with greater phase margin.
Adjustable Output Resistor Selection
Output Capacitor
The output voltage on the step-down converter is
programmed with external resistors R2 and R6. To
limit the bias current required for the external feedback resistor string while maintaining good noise
immunity, the minimum suggested value for R6 is
59kΩ. Although a larger value will further reduce
quiescent current, it will also increase the impedance of the feedback node, making it more sensitive
to external noise and interference. Table 2 summarizes the resistor values for various output voltages
with R6 set to either 59kΩ for good noise immunity
or 221kΩ for reduced no load input current.
The output capacitor limits the output ripple and
provides holdup during large load transitions. A
4.7µF to 10µF X5R or X7R ceramic capacitor typi-
With enhanced transient response for extreme
pulsed load application, an external feed-forward
capacitor (C1 in Fig.3) can be added.
In applications where the input power source lead
inductance cannot be reduced to a level that does
not affect the converter performance, a high ESR
tantalum or aluminum electrolytic should be placed
in parallel with the low ESR, ESL bypass ceramic.
This dampens the high Q network and stabilizes
the system.
2503.2007.04.1.1
15
AAT2503
Adjustable 3-Channel Regulator
R6 = 59kΩ
R6 = 221kΩ
VOUT (V)
R2 (kΩ)
R2 (kΩ)
0.9*
1.0
1.1
1.2
1.3
1.4
1.5
1.8
1.85
2.0
2.5
2.8
3.0
3.3
0
6.65
13.3
19.6
26.1
32.4
39.2
59.0
61.9
71.5
105
124
137
158
0
24.3
48.7
73.2
97.6
124
147
221
232
274
392
464
511
590
Table 2: Step-Down Converter Resistor Values
for Various Output Voltages.
Thermal Calculations
There are three types of losses associated with the
AAT2503 step-down converter: switching losses,
conduction losses, and quiescent current losses.
Conduction losses are associated with the RDS(ON)
characteristics of the power output switching
devices. Switching losses are dominated by the gate
charge of the power output switching devices. At full
load, assuming continuous conduction mode (CCM),
a simplified form of the LDO losses is given by:
PTOTAL =
IO2 · (RDSON(HS) · VO + RDSON(LS) · [VIN - VO])
VIN
+ (tsw · F · IO + IQ) · VIN
IQ is the step-down converter quiescent current.
The term tsw is used to estimate the full load stepdown converter switching losses.
For the condition where the step-down converter is
in dropout at 100% duty cycle, the total device dissipation reduces to:
Since RDS(ON), quiescent current, and switching
losses all vary with input voltage, the total losses
should be investigated over the complete input
voltage range.
Given the total losses, the maximum junction temperature can be derived from the θJA for the
QFN34-20 package which is 50°C/W.
TJ(MAX) = PTOTAL · ΘJA + TAMB
LDO Linear Regulator 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 AAT2503 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
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.
Output Capacitor
For proper load voltage regulation and operational
stability, a capacitor is required between pins OUTA,
OUTB, 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 AAT2503 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.
PTOTAL = IO2 · RDSON(HS) + IQ · VIN
* For the 0.9V output, R6 is open.
16
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
Applications utilizing the exceptionally low output
noise and optimum power supply ripple rejection
characteristics of the AAT2503 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 AAT2503. 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 not prone to
incorrect connection damage.
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.
Adjustable Output Resistor Selection
The output voltage on the linear regulator is programmed with external resistors: R4 and R7 for
LDOA and R5 and R8 for LDOB. Table 3 summarizes the resistor values for various output voltages with R4 and R5 set to either 59kΩ for good
noise immunity or 221kΩ for reduced no load input
current.
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.
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
LDO
VOUT (V)
0.6*
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.8
1.85
2.0
2.5
3.3
R7, R8 = 59kΩ
R7, R8 = 221kΩ
R4, R5 (kΩ)
R4, R5 (kΩ)
0
19.6
29.4
39.2
49.9
59.0
68.1
78.7
88.7
118
124
137
187
267
0
75
113
150
187
221
261
301
332
442
464
523
715
1000
Table 3: LDO Linear Regulators Resistor
Values for Various Output Voltages.
* For the 0.6V output, R7 and R8 are open.
2503.2007.04.1.1
17
AAT2503
Adjustable 3-Channel Regulator
POK Output
No-Load Stability
LDOA of the AAT2503 features an integrated
Power OK comparator 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 LDOA is
in shutdown, the POK output is pulled low. Connect
a pull-up resistor from POK to OUTA.
The LDOs in the AAT2503 are 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.
Enable Function
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 the
cathode to VIN and anode to VOUT). The Schottky
diode forward voltage should be less than 0.45V.
The AAT2503 features an LDO regulator enable/disable function. Each LDO has its own dedicated
enable pin. These pins (ENA, ENB) are active high
and are compatible with CMOS logic. To assure the
LDO regulators will switch on, ENA/B must be
greater than 1.4V. The LDO regulators will shut
down when the voltage on the ENA/B pins falls
below 0.6V. In shutdown, the LDO regulators 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.
Short-Circuit Protection
The AAT2503 contains internal short-circuit protection that will trigger when the output load current
exceeds the internal threshold limit. Under shortcircuit 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
Each of the two LDOs of the AAT2503 has an internal thermal protection circuit which will turn on when
the device die temperature exceeds 140°C. The
LDO regulator outputs will remain in a shutdown
state until the internal die temperature falls back
below the ~125°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.
18
Reverse Output-to-Input Voltage
Conditions and Protection
Thermal Considerations and High
Output Current Applications
The LDOs of the AAT2503 are designed to deliver
continuous output load currents of 150mA each
under normal operation. This is desirable for circuit
applications where there might be a brief high inrush 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.
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
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) =
TJ(MAX) - TA
θJA
Constants for the AAT2503 are TJ(MAX) (the maximum junction temperature for the device, which is
125°C) and θJA = 50°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 800mW. At TA = 25°C, the maximum package power dissipation is 2W.
The maximum continuous output current for the
AAT2503 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 · IGND)] + [(VIN - VOUTB)IOUTB + (VIN · IGND)]
Layout
The suggested PCB layout for the AAT2503 is
shown in Figures 2 and 3. The following guidelines
should be used to help ensure a proper layout.
1. The input capacitors (C4, C7, C8, and C9)
should connect as closely as possible to VIN
and PGND.
2. The output capacitor (C5, and C6) of the LDOs
connect as closely as possible to OUT. C2 and
L1 should be connected as closely as possible.
The connection of L1 to the LX pin should be as
short as possible. Do not make the node small
by using a narrow trace. The trace should be
kept wide, direct, and short.
3. The feedback trace should be separate from
any power trace and connect as closely as possible to the load point. Sensing along a high-
2503.2007.04.1.1
current load trace will degrade DC load regulation. Feedback resistors should be placed as
closely as possible to VOUT to minimize the
length of the high impedance feedback trace. If
possible, they should also be placed away from
the LX (switching node) and inductor to
improve noise immunity.
4. The resistance of the trace from the load return
to the PGND should be kept to a minimum.
This will help to minimize any error in DC regulation due to differences in the potential of the
internal signal ground and the power ground.
5. Ensure all ground pins are tied to the ground
plane. No pins should be left floating. For maximum power dissipation, it is recommended that
the exposed Pad must be soldered to a good
conductive PCB ground plane layer to further
increase local heat dissipation.
19
AAT2503
Adjustable 3-Channel Regulator
Figure 1: AAT2503 Evaluation Board
Top Side Layout.
Figure 2: AAT2503 Evaluation Board
Bottom Side Layout.
SYNC
U1
R10
100k
5
AAT2503
FB
LX
9
LX
L1
4
VIN
SYNC
LX
2.2μH CDRH2D14
R1
13
VIN
OUTA
17
100
3
2
1
C4
0.1μF
18
3
2
1
VINB
19
C9
1μF
1
2
3
1
2
3
3
1
2
3
ENA
GND
POK
VINB
FBA
15
2
R12
100k
C2
10μF
R3
16
R2
C1
100pF
C3
0.01μF
R4
OUTA
10
14
ENB
VINA
100k
C8
1μF
VINA
EN
VOUT_BUCK
8
VP
EN/SET
OUTB
FBB
ENB
PGND
ENA
AGND
C7
10μF
20
OUTB
R5
1
7
6
R7
59.0k
R8
59.0k
C6
2.2μF
C5
2.2μF
R6
59.0k
GND
GND
POK
GND
C5, C6 2.2μF, 10V, X5R, 0603 GRM188R61A225KE34
C8, C9 1μF, 6.3V, X5R, 0603 GRM185R60J105KE26
C2, C7 10μF, 6.3V, X5R, 0805 GRM219R60J106KE19
L1 Sumida CDRH2D14 or Coltronics SD3814
U1 AAT2503 QFN34-20
Figure 3: AAT2503 Evaluation Board Schematic.
20
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
Manufacturer
Part Number
Murata
Murata
Murata
Murata
Murata
GRM219R60J106KE19
GRM188R60J475KE19
GRM188R61A225KE34
GRM188R61A105KA61
GRM185R60J105KE26
Value (µF)
Voltage Rating
Temp. Co.
Case Size
10
4.7
2.2
1.0
1.0
6.3
6.3
10
10
6.3
X5R
X5R
X5R
X5R
X5R
0805
0603
0603
0603
0603
Table 4: Surface Mount Capacitors.
Manufacturer
Sumida
Sumida
Sumida
Coiltronics
Coiltronics
Coiltronics
Taiyo Yuden
Taiyo Yuden
Taiyo Yuden
Part Number
Inductance
(µH)
Saturated Rated
Current (mA)
DCR
(mΩ)
Size (mm)
LxWxH
Type
CDRH2D14-1R5
CDRH2D14-2R2
CDRH2D14-3R3
SD3812-1R5
SD3812-2R2
SD3812-3R3
NR3010-1R5
NR3010-2R2
NR3010-3R3
1.5
2.2
3.3
1.5
2.2
3.3
1.5
2.2
3.3
1800
1500
1200
1580
1320
1100
1200
1100
870
63
94
125
78
111
159
80
95
140
3.2x3.2x1.55
3.2x3.2x1.55
3.2x3.2x1.55
4.0x4.0x1.2
4.0x4.0x1.2
4.0x4.0x1.2
3.0x3.0x1.0
3.0x3.0x1.0
3.0x3.0x1.0
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Table 5: Suggested Inductors and Suppliers.
2503.2007.04.1.1
21
AAT2503
Adjustable 3-Channel Regulator
Ordering Information
Voltage
Package
Channel 1
Channel 2
Channel 3
Marking1
Part Number (Tape and Reel)2
QFN34-20
0.9V
0.6V
0.6V
TPXYY
AAT2503IZL-BAA-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.
Legend
Voltage
Adjustable
(0.6V)
0.9
1.2
1.5
1.8
1.9
2.5
2.6
2.7
2.8
2.85
2.9
3.0
3.3
4.2
Code
A
B
E
G
I
Y
N
O
P
Q
R
S
T
W
C
1. XYY = assembly and date code.
2. Sample stock is generally held on part numbers listed in BOLD.
22
2503.2007.04.1.1
AAT2503
Adjustable 3-Channel Regulator
Package Information1
QFN34-20
Detail "A"
Index Area
(D/2 x E/2)
Detail "B"
4.00 ± 0.05
0.925 ± 0.125
7.5° ± 7.5°
0.025 ± 0.025
0.214 ± 0.036
Side View
3.00 ± 0.05
Top View
Bottom View
0.40 ± 0.10
0.075 ± 0.075
Option B:
R0.30 (4x) max
Round corner
0.50 ± 0.05
Option A:
C0.30 (4x) max
Chamfered corner
0.24 ± 0.06
Pin 1 indicator
(optional)
Detail "A"
Detail "B"
All dimensions in millimeters.
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.
© 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. Except as provided in AnalogicTech’s terms and conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied warranty relating to the sale and/or use of AnalogicTech products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent,
copyright or other intellectual property right. In order to minimize risks associated with the customer’s applications, adequate 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 support this warranty.
Specific testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated.
All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders.
Advanced Analogic Technologies, Inc.
830 E. Arques Avenue, Sunnyvale, CA 94085
Phone (408) 737- 4600
Fax (408) 737- 4611
2503.2007.04.1.1
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