SKYWORKS AAT2505IWP-AO-T1

DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
General Description
Features
The AAT2505 is a member of Skyworks' Total Power
Management IC (TPMIC™) product family. It is a low
dropout (LDO) linear regulator and a step-down converter with an input voltage range of 2.7V to 5.5V, making it ideal for applications with single cell lithium-ion /
polymer batteries.
• VIN Range: 2.7V to 5.5V
• 300mA LDO
▪ 400mV Dropout Voltage at 300mA
▪ High Accuracy: ±1.5%
▪ Fast Line / Load Transient Response
▪ Power OK Output
• 600mA Step-Down Converter
▪ Up To 98% Efficiency
▪ 27μA No Load Quiescent Current
▪ Shutdown Current <1μA
▪ Low RDS(ON) Integrated Power Switches
▪ Fast Turn-On Time (150μs Typical)
▪ Low Dropout 100% Duty Cycle
▪ 1.4MHz Switching Frequency
▪ Internal Soft Start
• Over-Temperature and Current Limit Protection
• TDFN33-12 Package
• -40°C to +85°C Temperature Range
The LDO has an independent input pin and is capable of
delivering up to 300mA of current. The linear regulator
has been designed for high-speed turn-on and turn-off
performance, fast transient response, and good power
supply rejection ratio (PSRR). Other features include low
quiescent current, low dropout voltage, and a Power-OK
(POK) open drain output signaling when VOUT is in regulation.
The 600mA step-down converter is designed to operate
with 1.4MHz of switching frequency, minimizing external
component size and cost while maintaining a low 27μA
no load quiescent current.
Peak current mode control with internal compensation
provides a stable converter with a low equivalent series
resistance (ESR) ceramic output capacitor for extremely
low output ripple.
For maximum battery life with high voltage outputs, the
step-down converter duty cycle increases to 100%. The
output voltage is either fixed or adjustable with an integrated P- and N-channel MOSFET power stage and
1.4MHz switching frequency.
Applications
•
•
•
•
•
•
Cellular Phones
Digital Cameras
Handheld Instruments
Microprocessor/DSP Core/IO Power
PDAs and Handheld Computers
Portable Media Players
The AAT2505 is available in a Pb-free, 12-pin TDFN33
package and is rated over a temperature range of -40°C
to +85°C.
Typical Application
VIN = 2.7V to 5.5V
3.3V at 300mA
9
6
R3 100kΩ
7
8
VP
VCC
VLDO
EN
ENLDO
LX
OUT
FB
POK
SGND
GND
PGND
4
100
2.5V at 600mA
10
L1
2
6.8μH
11
12
1
U1
AAT2505
C1
4.7μF
Efficiency (%)
3
5
C4
2.2μF
Efficiency
(VOUT = 2.5V; L = 6.8µH)
C3
10μF
90
VIN = 3.3V
80
70
60
0.1
L1 Sumida CDRH3D16-4R7 C1 Murata GRM219R61A475KE19
C3 Murata GRM21BR60J106KE19
1
10
100
1000
Output Current (mA)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
1
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Pin Descriptions
Pin #
Symbol
1
PGND
2
3
4
5
6
LX
VP
VCC
VLDO
OUT
7
POK
8
9
GND
ENLDO
10
EN
11
FB
12
SGND
EP
Function
Step-down converter power ground return pin. Connect to the output and input capacitor return. See section on PCB layout guidelines and evaluation board layout diagram.
Power switching node. Output switching node that connects to the output inductor.
Step-down converter power stage supply voltage. Must be closely decoupled to PGND.
Step-down converter bias supply. Connect to VP.
LDO input voltage; should be decoupled with 1μF or greater capacitor.
300mA LDO output pin. A 2.2μF or greater output low-ESR ceramic capacitor is required for stability.
Power-OK output for the LDO. This open drain output is low when the OUT is out of regulation. Connect a
pull-up resistor from POK to OUT or VLDO. When LDO is in shutdown (ENLDO = 0V), POK is pulled low.
LDO ground connection pin.
Enable pin for LDO. When connected low, LDO is disabled and consumes less than 1μA of current.
Step-down converter enable. When connected low, the step-down converter is disabled and consumes
less than 1μA.
Step-down converter feedback input pin. For fixed output voltage versions, this pin is connected to the
converter output, forcing the converter to regulate to the specific voltage. For adjustable output versions,
an external resistive divider ties to this point and programs the output voltage to the desired value.
Step-down converter signal ground. For external feedback, return the feedback resistive divider to this
ground. For internal fixed version, tie to the point of load return. See section on PCB layout guidelines
and evaluation board layout diagram.
Exposed paddle (bottom). Use properly sized vias for thermal coupling to the ground plane. See section
on PCB layout guidelines.
Pin Configuration
TDFN33-12
(Top View)
PGND
LX
VP
VCC
VLDO
OUT
2
1
12
2
11
3
10
4
9
5
8
6
7
SGND
FB
EN
ENLDO
GND
POK
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Absolute Maximum Ratings1
Symbol
VP, VLDO
VLX
VFB
VEN
TJ
TLEAD
Description
Input Voltages to GND
Lx to GND
FB to GND
EN 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
JA
Description
Maximum Power Dissipation
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 with exposed paddle connected to ground plane.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
3
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Electrical Characteristics1
VIN = VLDO = VOUT(NOM) + 1V for VOUT options greater than 1.5V. VIN = VLDO = 2.5V for VOUT ≤ 1.5V. IOUT = 1mA, COUT =
2.2μF, CIN = 1μF, TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C.
Symbol
Description
Conditions
VOUT
Output Voltage Tolerance
IOUT = 1mA to 300mA
VIN
Input Voltage
Min
Typ
Max
Units
1.5
2.5
%
5.5
V
600
mV
0.09
%/V
LDO
VDO
VOUT/
VOUT* VIN
Dropout Voltage3, 4
IOUT = 300mA
Line Regulation
VIN = VOUT + 1V to 5V
TA = 25°C
TA = -40°C to +85°C
VOUT(Line)
Dynamic Line Regulation
VOUT(Load)
IOUT
ISC
IQLDO
Dynamic Load Regulation
Output Current
Short-Circuit Current
LDO Quiescent Current
IOUT = 300mA, VIN = VOUT + 1V to VOUT + 2V,
TR/TF = 2μs
IOUT = 1mA to 300mA, TR <5μs
VOUT > 1.3V
VOUT < 0.4V
VIN = 5V, No Load, ENLDO = VIN
POK Trip Threshold
VOUT Rising, TA = 25°C
VPOK
VPOKHYS
POK Hysteresis
VPOK(OL)
IPOK
POK Output Voltage Low
POK Output Leakage Current
ISHDN
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 +
VDO2
400
2.5
mV
60
0.4
1.0
mV
mA
A
μA
% of
VOUT
% of
VOUT
V
μA
1.0
μA
300
90
1
70
125
94
98
1.0
ISINK = 1mA
VPOK < 5.5V, VOUT in Regulation
VIN = 5V; ENLDO = GND, EN = SGND =
PGND
1kHz
10kHz
IOUT = 10mA
1MHz
65
45
42
145
15
250
22
dB
°C
°C
μVRMS
ppm/°C
1. The AAT2505 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. To calculate the minimum LDO input voltage, use the following equation: VIN(MIN) = VOUT(MAX) + VDO(MAX), as long as VIN 2.5V.
3. For VOUT < 2.1V, VDO = 2.5 - VOUT.
4. VDO is defined as VIN - VOUT when VOUT is 98% of nominal.
4
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Electrical Characteristics1
IOUT = 600mA; typical values are TA = 25°C, VIN = VCC = VP = 3.6V.
Symbol
Description
Conditions
Buck Converter
Input Voltage
VIN
VUVLO
VOUT
VOUT
IQBUCK
ISHDN
ILIM
RDS(ON)H
RDS(ON)L
ILXLK
UVLO Threshold
Output Voltage Tolerance
Output Voltage Range
Step-Down Converter Quiescent Current
Shutdown Current
P-Channel Current Limit
High Side Switch On Resistance
Low Side Switch On Resistance
LX Leakage Current
VLinereg
Line Regulation
VFB
FB Threshold Voltage Accuracy
IFB
FB Leakage Current
RFB
FB Impedance
TS
Start-Up Time
FOSC
Oscillator Frequency
TSD
Over-Temperature Shutdown Threshold
THYS
Over-Temperature Shutdown Hysteresis
Logic Signals
VEN(L)
Enable Threshold Low
VEN(H)
Enable Threshold High
IEN(H)
Leakage Current
Min
Typ
2.7
VIN Rising
Hysteresis
VIN Falling
IOUT = 0 to 600mA, VIN = 2.7V to 5.5V
Max
Units
5.5
2.7
3.0
VIN
V
V
mV
V
%
V
70
μA
1.0
μA
mA


1.0
μA
100
1.8
-3.0
0.6
ENLDO = GND, No Load, 0.6V Adjustable
Version
EN = SGND = PGND, ENLDO = GND
27
800
0.45
0.40
VIN = 5.5V, VLX = 0 to VIN, EN = SGND =
PGND
VIN = 2.7V to 5.5V
0.6V Output, No Load, TA = 25°C
0.6V Output
> 0.6V Output
From Enable to Output Regulation
TA = 25°C
591
0.1
600
609
0.2
250
1.0
150
1.4
140
15
2.0
0.6
1.4
-1.0
1.0
%/V
mV
μA
k
μs
MHz
°C
°C
V
V
μA
1. The AAT2505 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.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
5
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA = 25°C.
LDO Dropout Voltage vs. Temperature
LDO Dropout Characteristics
(EN = GND; ENLDO = VIN)
(EN = GND; ENLDO = VIN)
3.20
IL = 300mA
480
420
Output Voltage (V)
Dropout Voltage (mV)
540
360
300
IL = 100mA
IL = 150mA
240
180
120
60
IOUT = 0mA
2.80
IOUT = 300mA
IOUT = 150mA
2.60
2.40
2.20
IL = 50mA
0
-40 -30 -20 -10 0
3.00
IOUT = 10mA
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)
3.00
3.10
3.20
3.30
Input Voltage (V)
LDO Dropout Voltage vs. Output Current
LDO Ground Current vs. Input Voltage
(EN = GND; ENLDO = VIN)
(EN = GND; ENLDO = VIN)
90.00
500
Ground Current (μA)
Dropout Voltage (mV)
450
400
350
300
85°C
250
200
25°C
150
-40°C
100
80.00
70.00
60.00
IOUT=300mA
50.00
IOUT=0mA
30.00
IOUT=10mA
20.00
10.00
50
0
0.00
0
50
100
150
200
250
300
2
2.5
Output Voltage Variation (%)
3
3.5
4
4.5
Input Voltage (V)
Output Current (mA)
LDO Output Voltage vs. Temperature
LDO Initial Power-Up Response Time
(EN = GND; ENLDO = VIN)
(EN = GND; ENLDO = VIN)
0.05
0.00
VENLDO (5V/div)
-0.05
-0.10
-0.15
-0.20
-0.25
-0.30
-0.35
-0.40
-0.45
-40 -30 -20 -10
0
10
20
30
40
50
60
Temperature (°°C)
6
IOUT=150mA
IOUT=50mA
40.00
70
80
90 100
VOUT (1V/div)
Time (400µs/div)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
5
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA = 25°C.
LDO Turn-Off Response Time
LDO Turn-On Time From Enable (VIN present)
(EN = GND; ENLDO = VIN)
(EN = GND; ENLDO = VIN)
VENLDO = 5V/div
VENLDO (5V/div)
VOUT (1V/div)
Time (50µs/div)
Time (5µs/div)
LDO Line Transient Response
LDO Load Transient Response
(EN = GND; ENLDO = VIN)
(EN = GND; ENLDO = VIN)
3.03
2.85
VIN
4
3.02
3
3.01
2
3.00
VOUT
1
2.99
0
2.98
500
400
VOUT
2.80
300
2.75
200
2.70
100
2.65
0
Output Current (mA)
2.90
Output Voltage (V)
5
3.04
Output Voltage (V)
6
Input Voltage (V)
VIN = 4V
VOUT = 1V/div
IOUT
2.60
-100
Time (100µs/div)
Time (100µs/div)
LDO Load Transient Response 300mA
800
2.90
700
2.80
600
VOUT
2.70
500
2.60
400
2.50
300
2.40
2.30
200
100
IOUT
2.20
0
2.10
-100
Output Current (mA)
Output Voltage (V)
(EN = GND; ENLDO = VIN)
3.00
Time (10µs/div)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
7
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA = 25°C.
LDO ENLDO vs. VIN
LDO Over-Current Protection
(EN = GND; ENLDO = VIN)
Output Current (mA)
1200
1.250
1.225
1000
1.200
800
VIH
1.175
600
1.150
400
1.125
200
1.100
0
1.075
VIL
1.050
2.5
-200
3.0
3.5
Time (50ms/div)
Step-Down Converter Efficiency vs. Load
4.5
5.0
5.5
Step-Down Converter DC Regulation
(VOUT = 3.3V; L = 10μ
μH; ENLDO = GND)
(VOUT = 3.3V; L = 6.8µH; ENLDO = GND)
1.0
90
Output Error (%)
100
Efficiency (%)
4.0
Input Voltage (V)
VIN = 3.9V
VIN = 4.2V
80
70
VIN = 5.0V
0.5
0.0
VIN = 4.2V
-0.5
-1.0
60
0.1
1
10
100
0.1
1000
1
Output Current (mA)
10
100
1000
Output Current (mA)
Step-Down Converter Efficiency vs. Load
Step-Down Converter DC Regulation
(VOUT = 2.5V; L = 10μ
μH; ENLDO = GND)
(VOUT = 2.5V; L = 6.8µH; ENLDO = GND)
1.0
100
Output Error (%)
Efficiency (%)
VIN = 3.3V
90
VIN = 3.0V
VIN = 3.6V
80
70
VIN = 4.2V
0.0
VIN = 3.6V
-0.5
VIN = 3.0V
-1.0
60
0.1
1
10
Output Current (mA)
8
VIN = 5.0V
0.5
100
1000
0.1
1
10
100
Output Current (mA)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
1000
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA = 25°C.
Step-Down Converter Efficiency vs. Load
Step-Down Converter DC Regulation
(VOUT = 1.5V; L = 4.7μ
μH; ENLDO = GND)
(VOUT = 1.5V; L = 4.7μ
μH; ENLDO = GND)
3.0
100
VIN = 2.7V
VIN = 3.6V
Output Error (%)
Efficiency (%)
90
80
VIN = 4.2V
70
60
50
VIN = 4.2V
2.0
VIN = 3.6V
1.0
0.0
VIN = 2.7V
-1.0
-2.0
-3.0
0.1
1
10
100
1000
0.1
1
10
Output Current (mA)
Step-Down Converter
Frequency vs. Input Voltage
Step-Down Converter
Output Voltage Error vs. Temperature
(VOUT = 1.8V; EN = VIN; ENLDO = GND)
(VIN = 3.6V; VO = 1.5V; EN = VIN; ENLDO = GND)
2.0
0.5
Output Error (%)
Frequency Variation (%)
1000
Output Current (mA)
1.0
0.0
-0.5
-1.0
-1.5
-2.0
1.0
0.0
-1.0
-2.0
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
-40
-20
0
40
60
80
100
Step-Down Converter
Input Current vs. Input Voltage
Step-Down Converter
Switching Frequency vs. Temperature
(VO = 1.8V; EN = VIN; ENLDO = GND)
(VIN = 3.6V; VO = 1.5V; EN = VIN; ENLDO = GND)
35
15.0
Input Current (m
mA)
12.0
9.0
6.0
3.0
0.0
-3.0
-6.0
-9.0
85°C
30
25°C
25
20
-12.0
-15.0
-40
20
Temperature (°°C)
Input Voltage (V)
Frequency Variation (%)
100
-40°C
15
-20
0
20
40
Temperature (°°C)
60
80
100
2.5
3.0
3.5
4.0
4.5
5.0
5.5
Input Voltage (V)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
9
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA = 25°C.
Step-Down Converter
P-Channel RDS(ON) vs. Input Voltage
Step-Down Converter
N-Channel RDS(ON) vs. Input Voltage
(EN = VIN; ENLDO = GND)
750
700
700
650
120°C
650
100°C
RDS(ON) (mΩ
Ω)
RDS(ON) (mΩ
Ω)
(EN = VIN; ENLDO = GND)
750
600
550
85°C
500
450
25°C
400
120°C
100°C
600
550
500
85°C
450
400
350
25°C
350
300
300
2.5
3 .0
3.5
4 .0
4.5
5 .0
5.5
2.5
3 .0
3.5
Input Voltage (V)
4 .0
4.5
5 .0
5.5
Input Voltage (V)
(1mA to 300mA; VIN = 3.6V; VOUT = 2.5V;
C1 = 4.7µF; ENLDO = GND)
1.6
1.8
1.4
1.7
1.2
1.6
1.0
1.5
0.8
1.4
0.6
1.3
0.4
1.2
0.2
1.1
0.0
1.0
-0.2
2.9
1.8
2.7
1.6
2.5
1.4
2.3
1.2
2.1
1.0
1.9
0.8
1.7
0.6
1.5
0.4
1.3
0.2
1.1
0.0
-0.2
0.9
Time (50µs/div)
Load and Inductor Current
(200mA/div) (bottom)
1.8
1.9
Load and Inductor Current
(200mA/div) (bottom)
2.0
Output Voltage
(top) (V)
Step-Down Converter Load Transient Response
(1mA to 300mA; VIN = 3.6V; VOUT = 1.8V;
C1 = 4.7µF; ENLDO = GND)
Output Voltage
(top) (V)
Step-Down Converter Load Transient Response
Time (50µs/div)
Step-Down Converter Line Transient
Step-Down Converter Line Regulation
(VOUT = 1.8V)
(VOUT = 1.8V @ 400mA)
0.40
1.84
7.6
6.6
1.80
5.6
1.78
4.6
1.76
3.6
1.74
2.6
Time (25µs/div)
10
Accuracy (%)
1.82
Input Voltage
(bottom) (V)
Output Voltage
(top) (V)
0.30
0.20
IOUT = 10mA
0.10
0.00
IOUT = 1mA
-0.10
IOUT = 400mA
-0.20
-0.30
-0.40
2.5
3.0
3.5
4.0
4.5
5.0
Input Voltage (V)
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5.5
6.0
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Typical Characteristics
Step-Down Converter Output Ripple
(VIN = 3.6V; VOUT = 1.8V; 400mA;
EN = VIN; ENLDO = GND)
(VIN = 3.6V; VOUT = 1.8V; 400mA;
EN = VIN; ENLDO = GND)
5.0
4.0
1.6
VEN
VO
1.4
1.2
2.0
1.0
1.0
0.8
0.0
0.6
-1.0
0.4
-2.0
0.2
-3.0
IL
0.0
-4.0
-0.2
-5.0
-0.4
Time (100μ
μs/div)
40
0.9
20
0.8
0
0.7
-20
0.6
-40
0.5
-60
0.4
-80
0.3
-100
0.2
Inductor Current
(bottom) (A)
3.0
Output Voltage (AC Coupled)
(top) (mV)
Step-Down Converter Soft Start
Inductor Current
(bottom) (A)
Enable and Output Voltage
(top) (V)
Unless otherwise noted, VIN = 5V, TA = 25°C.
0.1
-120
Time (250ns/div)
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11
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Functional Block Diagram
VCC
FB
VP
Error
Amp.
DH
See
Note
LX
Logic
Voltage
Reference
DL
Control
Logic
EN
PGND
SGND
OUT
VLDO
Over-Current
Protection
Error
Amp.
ENLDO
Fast Start
Control
POK
Voltage
Reference
94%
+
-
GND
Note: Internal resistor divider included for
1.2V versions. For low voltage versions, the feedback pin is tied directly to the error amplifier input.
Functional Description
tions that require fast power supply timing.
The AAT2505 is a high performance power management
IC comprised of a buck converter and a linear regulator.
The high efficiency buck converter is capable of delivering up to 600mA. Designed to operate at 1.4MHz, the
converter requires only three external components (CIN,
COUT, and LX) and is stable with a ceramic output capacitor. The linear regulator delivers 300mA and also is stable with a ceramic output capacitor.
The high-speed turn-on capability is enabled through
implementation of a fast-start control circuit which accelerates the power-up behavior of fundamental control
and feedback circuits within the LDO regulator. Fast turnoff time response is achieved by an active output pulldown circuit, which is enabled when the LDO regulator is
placed in shutdown mode. This active fast shutdown circuit has no adverse effect on normal device operation.
The LDO regulator output has been specifically optimized
to function with low-cost, low-ESR ceramic capacitors;
however, the design will allow for operation over a wide
range of capacitor types.
Linear Regulator
The advanced circuit design of the linear regulator has
been specifically optimized for very fast start-up and
shutdown timing. This proprietary CMOS LDO has also
been tailored for superior transient response characteristics. These traits are particularly important for applica-
12
Other features include an integrated Power-OK comparator which indicates when the output is out of regulation.
The POK open-drain output is low when OUT is 6% below
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DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
its nominal regulation voltage. The open-drain signal is
held low when the linear regulator is in shutdown mode.
The regulator comes with complete short-circuit and
thermal protection. The combination of these two internal
protection circuits gives a comprehensive safety system
to guard against extreme adverse operating conditions.
The regulator features an enable/disable function. This
pin (ENLDO) is active high and is compatible with CMOS
logic. To assure the LDO regulator will switch on, the
ENLDO turn-on control level must be greater than 1.5V.
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.
When the regulator is in shutdown mode, an internal
20k resistor is connected between OUT and GND. This
is intended to discharge COUT when the LDO regulator is
disabled. The internal 20k resistor has no adverse
impact on device turn-on time.
Step-Down Converter
The AAT2505 buck is a constant frequency peak current
mode PWM converter with internal compensation. It is
designed to operate with an input voltage range of 2.7V
to 5.5V. The output voltage ranges from 0.6V to the input
voltage for the internally fixed version (see Figure 1) ,
and up to 3.3V for the externally adjustable version (see
Figure 2). The 0.6V fixed model is also the adjustable
version and is externally programmable with a resistive
divider. The converter MOSFET power stage is sized for
600mA load capability with up to 96% efficiency. Light
load efficiency exceeds 80% at a 500μA load.
Soft Start
The AAT2505 soft-start control prevents output voltage
overshoot and limits inrush current when either the input
power or the enable input is applied. When pulled low,
the enable input forces the converter into a low-power,
non-switching state with a bias current of less than 1μA.
A startup time of 150μs is achieved across the operating
range.
Low Dropout Operation
For conditions where the input voltage drops to the output voltage level, the converter duty cycle increases to
100%. As 100% duty cycle is approached, the minimum
off-time initially forces the high side on-time to exceed
the 1.4MHz clock cycle and reduce the effective switching frequency. Once the input drops below the level
where the output can be regulated, the high side
P-channel MOSFET is turned on continuously for 100%
duty cycle. At 100% duty cycle, the output voltage
tracks the input voltage minus the IR drop of the high
side P-channel MOSFET RDS(ON).
Low Supply
The under-voltage lockout (UVLO) guarantees sufficient
VIN bias and proper operation of all internal circuitry prior
to activation.
Fault Protection
For overload conditions, the peak inductor current is limited. Thermal protection disables switching when the
internal dissipation or ambient temperature becomes
excessive. The junction over-temperature threshold is
140°C with 15°C of hysteresis.
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13
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
VIN
VIN
C3
10μF
3
5
9
VOUTLDO
6
7
C4
4.7μF
R3
100kΩ
8
VP
VCC
VLDO
EN
ENLDO
LX
OUT
FB
POK
SGND
GND
PGND
4
10
2
11
L1
VOUTBUCK
C3
10μF
3
5
9
4.7μH
VOUTLDO
6
12
7
1
C1
4.7μF
U1
AAT2505
Figure 1: AAT2505 Fixed Output.
C4
4.7μF
R3
100kΩ
8
VP
VCC
VLDO
EN
ENLDO
LX
OUT
FB
POK
SGND
GND
PGND
U1
AAT2505
4
10
2
11
VOUTBUCK
L1
4.7μH
R1
12
1
C8
100pF
R2
59k
C1
4.7μF
Figure 2: AAT2505 with Adjustable Step-Down
Output and Enhanced Transient Response.
Applications Information
load is less than 10mA, the minimum value for COUT can
be as low as 0.47μF.
Linear Regulator
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.
Input and Output Capacitors: An input capacitor is
not required for basic operation of the linear regulator.
However, if the AAT2505 is physically located more than
three centimeters from an input power source, a CIN
capacitor will be needed for stable operation. Typically, a
1μF or larger capacitor is recommended for CIN in most
applications. CIN should be located as closely to the
device VIN pin as practically possible.
An input capacitor greater than 1μF will offer superior
input line transient response and maximize 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 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.
For proper load voltage regulation and operational stability, a capacitor is required between OUT and GND. The
COUT capacitor connection to the LDO regulator ground
pin should be made as directly as practically possible for
maximum device performance. Since the regulator has
been designed to function with very low ESR capacitors,
ceramic capacitors in the 1.0μF to 10μF range are recommended for best performance. Applications utilizing
the exceptionally low output noise and optimum power
supply ripple rejection should use 2.2μF or greater for
COUT. In low output current applications, where output
14
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 the regulator, 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
that 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 pack-
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DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
age size. Consult capacitor vendor datasheets carefully
when selecting capacitors for LDO regulators.
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 adjustable and low-voltage fixed versions of the
AAT2505 is 0.24A/μs. This equates to a slope compensation that is 75% of the inductor current down slope for
a 1.5V output and 4.7μH inductor.
m=
0.75 · VO 0.75 · 1.5V
A
=
= 0.24
L
4.7μH
μs
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 4.7μH CDRH3D16 series inductor selected from
Sumida has a 105m DCR and a 900mA DC current rating. At full load, the inductor DC loss is 17mW which gives
a 2.8% loss in efficiency for a 400mA, 1.5V output.
Input Capacitor
Select a 4.7μF to 10μF X7R or X5R ceramic capacitor for
the input. To estimate the required input capacitor size,
determine the acceptable input ripple level (VPP) and
solve for C. The calculated value varies with input voltage and is a maximum when VIN is double the output
voltage.
This is the internal slope compensation for the adjustable (0.6V) version or low-voltage fixed versions. When
externally programming the 0.6V version to 2.5V, the
calculated inductance is 7.5μH.
L=
CIN =
⎛ VPP
⎞
- ESR · FS
⎝ IOBUCK
⎠
⎞ 1
VOBUCK ⎛
V
· 1 - OBUCK = for VIN = 2 × VOBUCK
⎝
VIN
VIN ⎠ 4
0.75 · VO 0.75 · VO
μs
=
≈3
· VO
A
m
A
0.24A μs
=3
VOBUCK ⎛ VOBUCK⎞
· 1⎝
VIN
VIN ⎠
μs
· 2.5V = 7.5μH
A
CIN(MIN) =
1
⎛ VPP
⎞
- ESR · 4 · FS
⎝ IOBUCK
⎠
In this case, a standard 6.8μH value is selected.
For high-voltage fixed versions (2.5V and above), m =
0.48A/μs. Table 1 displays inductor values for the
AAT2505 fixed and adjustable options.
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
Configuration
0.6V Adjustable With External Feedback
Fixed Output
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 = IOBUCK ·
⎞
VOBUCK ⎛
V
· 1 - OBUCK
⎝
VIN
VIN ⎠
Output Voltage
Inductor
1V, 1.2V
1.5V, 1.8V
2.5V, 3.3V
0.6V to 3.3V
2.2μH
4.7μH
6.8μH
4.7μH
Table 1: Inductor Values.
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DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
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.
VOBUCK ⎛ VOBUCK⎞
· 1=
⎝
VIN
VIN ⎠
D · (1 - D) =
0.52 =
1
2
for VIN = 2 x VOBUCK
IRMS(MAX) =
VOBUCK
IOBUCK
2
⎛
⎞
V
· 1 - OBUCK
VIN ⎠ appears in both the input voltThe term VIN ⎝
age ripple and input capacitor RMS current equations
and is a maximum when VOBUCK 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 AAT2505. 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.
The proper placement of the input capacitor (C2) can be
seen in the evaluation board layout in Figure 3.
Figure 3: AAT2505 Evaluation Board Top Side.
16
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.
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.
Output Capacitor
The output capacitor limits the output ripple and provides holdup during large load transitions. A 4.7μF to
10μF X5R or X7R ceramic capacitor provides sufficient
bulk capacitance to stabilize the output during large load
transitions and has the ESR and ESL characteristics necessary for low output ripple.
Figure 4: AAT2505 Evaluation Board
Bottom Side.
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DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
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 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.
The maximum output capacitor RMS ripple current is
given by:
IRMS(MAX) =
1
2· 3
·
VOUT · (VIN(MAX) - VOUT)
L · FS · VIN(MAX)
Dissipation due to the RMS current in the ceramic output
capacitor ESR is typically minimal, resulting in less than
a few degrees rise in hot-spot temperature.
Adjustable Output Resistor Selection
For applications requiring an adjustable output voltage,
the 0.6V version can be externally programmed. Resistors
R1 and R2 of Figure 5 program the output to regulate at
a voltage higher than 0.6V. To limit the bias current
required for the external feedback resistor string while
maintaining good noise immunity, the minimum suggested value for R2 is 59k. 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
R2 set to either 59k for good noise immunity or 221k
for reduced no load input current.
⎛ VOUT ⎞
⎛ 1.5V ⎞
R1 = V
-1 · R2 = 0.6V - 1 · 59kΩ = 88.5kΩ
⎝ REF ⎠
⎝
⎠
The adjustable version of the AAT2505, combined with
an external feedforward capacitor (C8 in Figures 2 and
5), delivers enhanced transient response for extreme
pulsed load applications. The addition of the feedforward
capacitor typically requires a larger output capacitor C1
for stability.
R2 = 59k
R2 = 221k
VOUT (V)
R1 (k)
R1 (k)
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
19.6
29.4
39.2
49.9
59.0
68.1
78.7
88.7
118
124
137
187
267
75
113
150
187
221
261
301
332
442
464
523
715
1000
Table 2: Adjustable Resistor Values For Use With
0.6V Step-Down Converter.
Thermal Calculations
There are three types of losses associated with the
AAT2505 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 step-down
converter and LDO losses is given by:
PTOTAL =
IOBUCK2 · (RDSON(H) · VOBUCK + RDSON(L) · [VIN - VOBUCK])
VIN
+ (tsw · FS · IOBUCK + IQBUCK + IQLDO) · VIN + IOLDO · (VIN - VOLDO)
IQBUCK is the step-down converter quiescent current and
IQLDO is the LDO quiescent current. The term tsw is used
to estimate the full load step-down converter switching
losses.
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DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
LX1
VOUTBUCK
C7
0.01µF
C1
4.7µF1
C2
10µF
L1
Table 3
VIN1
U1
1
2
3
4
3
2
1
5
6
LDO Input
C3
10µF
C9
n/a
AAT2505
PGND
SGND
LX
FB
VP
EN
VCC
ENLDO
IN
GND
OUT
POK
12
11
R1
Table 3
R2
59k
10
9
8
7
C4
4.7µF
C81
3
2
1
Buck Enable
3
2
1
LDO Enable
GND
GND
R3
100k
VOUTLDO
1
POK
Figure 5: AAT2505 Evaluation Board Schematic.
For the condition where the buck converter is in dropout
at 100% duty cycle, the total device dissipation reduces
to:
1.
2.
PTOTAL = IOBUCK2 · RDSON(H) + IOLDO · (VIN - VOLDO)
+ (IQBUCK + IQLDO) · VIN
3.
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 JA for the TDFN33-12 package which is 50°C/W.
4.
TJ(MAX) = PTOTAL · ΘJA + TAMB
PCB Layout
5.
The following guidelines should be used to ensure a
proper layout.
The input capacitor C2 should connect as closely as
possible to VP and PGND, as shown in Figure 4.
The output capacitor and inductor should be connected as closely as possible. The connection of the
inductor to the LX pin should also be as short as
possible.
The feedback trace should be separate from any
power trace and connect as closely as possible to the
load point. Sensing along a high-current load trace
will degrade DC load regulation. If external feedback
resistors are used, they should be placed as closely as
possible to the FB pin. This prevents noise from being
coupled into the high impedance feedback node.
The resistance of the trace from the load return to
GND 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.
For good thermal coupling, PCB vias are required
from the pad for the TDFN paddle to the ground
plane. The via diameter should be 0.3mm to 0.33mm
and positioned on a 1.2mm grid.
1. For step-down converter, enhanced transient configuration C8 = 100pF and C1 = 10μF.
18
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DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Step-Down Converter Design Example
Specifications
VOBUCK = 1.8V @ 400mA (adjustable using 0.6V version), Pulsed Load ILOAD = 300mA
VOLDO = 3.3V @ 300mA
VIN = 2.7V to 4.2V (3.6V nominal)
FS = 1.4MHz
TAMB = 85°C
1.8V Buck Output Inductor
L1 = 3
µs
µs
· VO2 = 3
· 1.8V = 5.4µH (use 4.7μH; see Table 1)
A
A
For Sumida inductor CDRH3D16, 4.7μH, DCR = 105m.
ΔIL1 =
⎛
VO
V ⎞
1.8V
1.8V ⎞
⎛
⋅ 1- O =
⋅ 1= 156mA
L1 ⋅ FS ⎝
VIN ⎠ 4.7μH ⋅ 1.4MHz ⎝
4.2V ⎠
IPKL1 = IO +
ΔIL1
= 0.4A + 0.068A = 0.468A
2
PL1 = IO2 ⋅ DCR = 0.4A2 ⋅ 105mΩ = 17mW
1.8V Buck Output Capacitor
VDROOP = 0.1V
COUT =
3 · ΔILOAD
3 · 0.3A
=
= 6.4µF; use 10µF
0.1V · 1.4MHz
VDROOP · FS
IRMS =
(VO) · (VIN(MAX) - VO)
1
1.8V · (4.2V - 1.8V)
·
= 45mArms
=
L1 · FS · VIN(MAX)
2 · 3 4.7µH · 1.4MHz · 4.2V
2· 3
1
·
Pesr = esr · IRMS2 = 5mΩ · (45mA)2 = 10µW
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DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
1.8V Buck Input Capacitor
Input Ripple VPP = 25mV
CIN =
IRMS =
1
⎛ VPP
⎞
- ESR · 4 · FS
⎝ IOBUCK
⎠
=
1
= 4.75μF
⎛ 25mV
⎞
- 5mΩ · 4 · 1.4MHz
⎝ 0.4A
⎠
IOBUCK
= 0.2Arms
2
P = esr · IRMS2 = 5mΩ · (0.2A)2 = 0.2mW
AAT2505 Total Losses
PTOTAL =
IOBUCK2 · (RDSON(H) · VOBUCK + RDSON(L) · [VIN - VOBUCK])
VIN
+ (tsw · FS · IOBUCK + IQBUCK + IQLDO) · VIN + (VIN - VOLDO) · IOLDO
TJ(MAX) = TAMB + ΘJA • PLOSS = 85°C + (50°C/W) • 395mW = 105°C
20
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
VOUT (V)
R1 (kΩ)
R1 (kΩ)
Adjustable Version (0.6V device)
R2 = 59kΩ
R2 = 221kΩ1
L1 (μH)
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
19.6
29.4
39.2
49.9
59.0
68.1
78.7
88.7
118
124
137
187
267
75.0
113
150
187
221
261
301
332
442
464
523
715
1000
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7 or 6.8
10
10
VOUT (V)
R1 (k)
Fixed Version
R2 Not Used
L1 (μH)
0.6-3.3V
0
4.7
Table 3: Evaluation Board Component Values.
Manufacturer
Part Number
Inductance
(μH)
Max DC
Current (A)
DCR ()
Size (mm)
LxWxH
Type
Sumida
Sumida
Murata
Murata
Murata
Coilcraft
Coilcraft
Coiltronics
Coiltronics
Coiltronics
Coiltronics
CDRH3D16-4R7
CDRH3D16/HP100
LQH32CN4R7M23
LQH32CN4R7M33
LQH32CN4R7M53
LPO6610-472
LPO3310-472
SDRC10-4R7
SDR10-4R7
SD3118-4R7
SD18-4R7
4.7
10
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
4.7
0.90
0.84
0.45
0.65
0.65
1.10
0.80
1.53
1.30
0.98
1.77
0.11
0.23
0.20
0.15
0.15
0.20
0.27
0.117
0.122
0.122
0.082
4.0x4.0x1.8
4.0x4.0x1.8
2.5x3.2x2.0
2.5x3.2x2.0
2.5x3.2x1.55
5.5x6.6x1.0
3.3x3.3x1.0
4.5x3.6x1.0
5.7x4.4x1.0
3.1x3.1x1.85
5.2x5.2x1.8
Shielded
Shielded
Non-Shielded
Non-Shielded
Non-Shielded
1mm
1mm
1mm Shielded
1mm Shielded
Shielded
Shielded
Table 4: Typical Surface Mount Inductors.
Manufacturer
Part Number
Value
Voltage
Temp. Co.
Case
Murata
Murata
GRM219R61A475KE19
GRM21BR60J106KE19
4.7μF
10μF
10V
6.3V
X5R
X5R
0805
0805
Table 5: Surface Mount Capacitors.
1. For reduced quiescent current R2 = 221k.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
21
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Ordering Information
Voltage
Package
Buck Converter
LDO
Marking1
Part Number (Tape and Reel)2
TDFN33-12
TDFN33-12
Adj.
Adj.
2.8V
2.6V
POXYY
PPXYY
AAT2505IWP-AQ-T1
AAT2505IWP-AO-T1
Skyworks Green™ products are compliant with
all applicable legislation and are halogen-free.
For additional information, refer to Skyworks
Definition of Green™, document number
SQ04-0074.
Legend
Voltage
Code
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
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
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2505
Dual Channel, Step-Down Converter/Linear Regulator
Package Information
TDFN33-121
Index Area
0.40 ± 0.05
0.1 REF
C0.3
0.45 ± 0.05
2.40 ± 0.05
3.00 ± 0.05
Detail "A"
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
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.
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Skyworks products are not intended for use in medical, lifesaving or life-sustaining applications, or other equipment in which the failure of the Skyworks products could lead to personal injury, death, physical or environmental damage. Skyworks customers using or selling Skyworks products for use in such applications do so at their own risk and agree to fully indemnify Skyworks for any damages resulting from such improper
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Customers are responsible for their products and applications using Skyworks products, which may deviate from published specifications as a result of design defects, errors, or operation of products outside of published parameters or design specifications. Customers should include design and operating safeguards to minimize these and other risks. Skyworks assumes no liability for applications assistance, customer product
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Skyworks, the Skyworks symbol, and “Breakthrough Simplicity” are trademarks or registered trademarks of Skyworks Solutions, Inc., in the United States and other countries. Third-party brands and names are for
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Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202018B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
23