AAT2554IRN-CAW-T1 [SKYWORKS]
Total Power Solution for Portable Applications; 用于便携式应用的总电源解决方案
| 型号： | AAT2554IRN-CAW-T1 |
| 厂家： | 
SKYWORKS SOLUTIONS INC. |
| 描述： | Total Power Solution for Portable Applications |
| 文件： | 总31页 (文件大小：2917K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Features
General Description
•
The AAT2554 is a fully integrated 500mA battery char-
ger, a 250mA step-down converter, and a 300mA low
dropout (LDO) linear regulator. The input voltage range
is 4V to 6.5V for the battery charger and 2.7V to 5.5V
for the step-down converter and linear regulator, making
it ideal for applications operating with single-cell lithium-
ion/polymer batteries.
Battery Charger:
Input Voltage Range: 4V to 6.5V
Programmable Charging Current up to 500mA
Highly Integrated Battery Charger
▪
▪
▪
•
Charging Device
•
Reverse Blocking Diode
•
Step-Down Converter:
Input Voltage Range: 2.7V to 5.5V
Output Voltage Range: 0.6V to VIN
250mA Output Current
Up to 96% Efficiency
30μA Quiescent Current
1.5MHz Switching Frequency
100μs Start-Up Time
▪
The battery charger is a complete constant current/con-
stant voltage linear charger. It offers an integrated pass
device, reverse blocking protection, high accuracy cur-
rent and voltage regulation, charge status, and charge
termination. The charging current is programmable via
external resistor from 15mA to 500mA. In addition to
these standard features, the device offers over-voltage,
current limit, and thermal protection.
▪
▪
▪
▪
▪
▪
•
•
Linear Regulator:
300mA Output Current
Low Dropout: 400mV at 300mA
Fast Line and Load Transient Response
High Accuracy: ±1.5%
▪
The step-down converter is a highly integrated converter
operating at a 1.5MHz switching frequency, minimizing
the size of external components while keeping switching
losses low. It has independent input and enable pins. The
output voltage ranges from 0.6V to the input voltage.
▪
▪
▪
70μA Quiescent Current
▪
Short-Circuit, Over-Temperature, and Current Limit
Protection
TDFN34-16 Package
The AAT2554 linear regulator is designed for fast tran-
sient response and good power supply ripple rejection.
Designed for 300mA of load current, it includes short-
circuit protection and thermal shutdown.
•
•
-40°C to +85°C Temperature Range
Applications
• Bluetooth™ Headsets
The AAT2554 is available in a Pb-free, thermally-
enhanced TDFN34-16 package and is rated over the
-40°C to +85°C temperature range.
• Cellular Phones
• Handheld Instruments
• MP3 and Portable Music Players
• PDAs and Handheld Computers
• Portable Media Players
Typical Application
Adapter/USB Input
VINB
ADP
ENB
VINA
STAT
EN_BAT
Enable
ENA
VOUTB
L= 3.0μH
AAT2554
BATT+
LX
BAT
RFB1
RFB2
FB
COUTB
COUT
VOUTA
OUTA
ISET
BATT-
RSET
COUTA
GND
Battery
Pack
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
1
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Pin Descriptions
Pin #
Symbol
Function
Feedback input. This pin must be connected directly to an external resistor divider. Nominal volt-
age is 0.6V.
1
FB
2, 10, 12, 14
GND
Ground.
Enable pin for the step-down converter. When connected to logic low, the step-down converter
is disabled and consumes less than 1μA of current. When connected to logic high, the converter
resumes normal operation.
3
ENB
4
5
VINA
OUTA
Linear regulator input voltage. Connect a 1μF or greater capacitor from this pin to ground.
Linear regulator output. Connect a 2.2μF capacitor from this pin to ground.
Enable pin for the battery charger. When connected to logic low, the battery charger is disabled
and consumes less than 1μA of current. When connected to logic high, the charger resumes nor-
mal operation.
6
EN_BAT
Charge current set point. Connect a resistor from this pin to ground. Refer to the Typical Charac-
teristics curves for resistor selection.
7
ISET
8
9
11
BAT
STAT
ADP
Battery charging and sensing.
Charge status input. Open drain status output.
Input for USB/adapter charger.
Enable pin for the linear regulator. When connected to logic low, the regulator is disabled and
consumes less than 1μA of current. When connected to logic high, the regulator resumes normal
operation.
13
ENA
Output of the step-down converter. Connect the inductor to this pin. Internally, it is connected to
the drain of both high- and low-side MOSFETs.
15
LX
16
EP
VINB
Input voltage for the step-down converter.
Exposed paddle (bottom); connect to ground directly beneath the package.
Pin Configuration
TDFN34-16
(Top View)
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VINB
LX
FB
GND
ENB
GND
ENA
GND
ADP
GND
STAT
VINA
OUTA
EN_BAT
ISET
BAT
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
2
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Absolute Maximum Ratings1
Symbol
Description
Value
Units
VINA, VINB
VADP
VLX
Input Voltage to GND
Adapter Voltage to GND
LX to GND
FB to GND
ENA, ENB, EN_BAT to GND
BAT, ISET, STAT
6.0
-0.3 to 7.5
V
V
V
V
V
V
°C
°C
-0.3 to VIN + 0.3
-0.3 to VIN + 0.3
-0.3 to 6.0
-0.3 to VADP + 0.3
-40 to 150
VFB
VEN
VX
TJ
Operating Junction Temperature Range
Maximum Soldering Temperature (at leads, 10 sec.)
TLEAD
300
Thermal Information
Symbol
Description
Value
Units
PD
JA
Maximum Power Dissipation
Thermal Resistance2
2.0
50
W
°C/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. Mounted on an FR4 board.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
3
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Electrical Characteristics1
VINB = 3.6V; TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C.
Symbol Description
Step-Down Converter
Conditions
Min
Typ
Max Units
VIN
Input Voltage
2.7
5.5
2.7
V
V
mV
V
VINB Rising
Hysteresis
VINB Falling
IOUTB = 0 to 250mA, VINB = 2.7V
to 5.5V
VUVLO
UVLO Threshold
200
1.8
-3.0
0.6
VOUT
Output Voltage Tolerance2
3.0
VINB
%
VOUT
IQ
ISHDN
ILIM
RDS(ON)H
RDS(ON)L
ILXLEAK
VLinereg
VIN
VFB
IFB
FOSC
TS
Output Voltage Range
Quiescent Current
Shutdown Current
P-Channel Current Limit
High-Side Switch On-Resistance
Low-Side Switch On-Resistance
LX Leakage Current
V
μA
μA
mA
No Load
ENB = GND
30
1.0
600
0.59
0.42
μA
VINB = 5.5V, VLX = 0 to VINB
VINB = 2.7V to 5.5V
1.0
/
Line Regulation
0.2
0.6
%/V
Feedback Threshold Voltage Accuracy
FB Leakage Current
Oscillator Frequency
VINB = 3.6V
VOUTB = 1.0V
0.591
0.609
0.2
V
μA
MHz
μs
°C
°C
V
1.5
100
140
15
Startup Time
From Enable to Output Regulation
TSD
Over-Temperature Shutdown Threshold
Over-Temperature Shutdown Hysteresis
Enable Threshold Low
Enable Threshold High
Input Low Current
THYS
VEN(L)
VEN(H)
IEN
0.6
1.0
1.4
-1.0
V
μA
VINB = VENB = 5.5V
1. The AAT2554 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correla-
tion with statistical process controls.
2. Output voltage tolerance is independent of feedback resistor network accuracy.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
4
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Electrical Characteristics1
VINA = VOUT(NOM) + 1V for VOUT options greater than 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
Min
Typ Max Units
Linear Regulator
TA = 25°C
TA = -40°C to +85°C
-1.5
-2.5
VOUT
1.5
%
IOUTA = 1mA
to 300mA
VOUT
VIN
Output Voltage Tolerance
2.5
Input Voltage
5.5
V
2
+ VDO
VDO
VOUT
OUT*VIN
Dropout Voltage3
Line Regulation
IOUTA = 300mA
400
600
mV
%/V
/
VINA = VOUTA + 1 to 5.0V
0.09
V
IOUTA = 300mA, VINA = VOUTA + 1 to VOUTA
+ 2, TR/TF = 2μs
IOUTA = 1mA to 300mA, TR <5μs
VOUTA > 1.2V
VOUTA < 0.4V
VINA = 5V; ENA = VIN
VINA = 5V; ENA = 0V
1kHz
VOUT(Line)
Dynamic Line Regulation
2.5
60
mV
VOUT(Load)
IOUT
ISC
IQ
ISHDN
Dynamic Load Regulation
Output Current
Short-Circuit Current
Quiescent Current
Shutdown Current
mV
mA
mA
μA
300
600
70
125
1.0
μA
65
45
43
PSRR
Power Supply Rejection Ratio
IOUTA =10mA
10kHz
1MHz
dB
TSD
THYS
eN
Over-Temperature Shutdown Threshold
Over-Temperature Shutdown Hysteresis
Output Noise
Output Voltage Temperature Coefficient
Enable Time Delay
Enable Threshold Low
Enable Threshold High
Enable Input Current
145
12
250
22
°C
°C
μVRMS
ppm/°C
μs
TC
TEN_DLY
VEN(L)
VEN(H)
IEN
15
0.6
1.0
V
V
μA
1.5
VENA = 5.5V
1. The AAT2554 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correla-
tion with statistical process controls.
2. VDO is defined as VIN - VOUT when VOUT is 98% of nominal.
3. For VOUT <2.3V, VDO = 2.5V - VOUT
.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
5
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Electrical Characteristics1
VINB = 3.6V; TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C.
Symbol Description
Conditions
Min
Typ
Max
Units
Battery Charger
Operation
VADP
VUVLO
Adapter Voltage Range
Under-Voltage Lockout (UVLO)
UVLO Hysteresis
Operating Current
Shutdown Current
4.0
3
6.5
4
V
V
mV
mA
μA
μA
Rising Edge
150
0.5
0.3
0.4
IOP
ISHUTDOWN
ILEAKAGE
Charge Current = 200mA
VBAT = 4.25V, EN_BAT = GND
VBAT = 4V, ADP Pin Open
1
1
2
Reverse Leakage Current from BAT Pin
Voltage Regulation
VBAT_EOC
VCH/VCH
VMIN
End of Charge Accuracy
4.158
2.85
4.20
0.5
3.0
4.242
3.15
V
%
V
Output Charge Voltage Tolerance
Preconditioning Voltage Threshold
Battery Recharge Voltage Threshold
VRCH
Measured from VBAT_EOC
-0.1
V
Current Regulation
ICH
ICH/ICH
VSET
Charge Current Programmable Range
Charge Current Regulation Tolerance
ISET Pin Voltage
15
500
1.1
mA
%
V
10
2
800
KI_A
Current Set Factor: ICH/ISET
Charging Devices
RDS(ON)
Charging Transistor On Resistance
VADP = 5.5V
0.9
Logic Control/Protection
VEN(H)
VEN(L)
VSTAT
ISTAT
VOVP
Enable Threshold High
Enable Threshold Low
Output Low Voltage
STAT Pin Current Sink Capability
Over-Voltage Protection Threshold
Pre-Charge Current
1.6
V
V
V
mA
V
%
%
0.4
0.4
8
STAT Pin Sinks 4mA
ICH = 100mA
4.4
10
10
ITK/ICHG
ITERM/ICHG
Charge Termination Threshold Current
1. The AAT2554 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correla-
tion with statistical process controls.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
6
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Typical Characteristics – Step-Down Converter
Efficiency vs. Load
(VOUT = 1.8V; L = 3.3µH)
DC Load Regulation
(VOUT = 1.8V; L = 3.3µH)
100
90
80
70
60
50
40
1.0
0.5
VIN = 5.0V
VIN = 2.7V
VIN = 3.6V
VIN = 3.6V
VIN = 5.5V
VIN = 5.5V
0.0
VIN = 2.7V
VIN = 4.2V
VIN = 5.0V
VIN = 4.2V
-0.5
-1.0
0.1
1
10
100
1000
0.1
1
10
100
1000
Output Current (mA)
Output Current (mA)
Efficiency vs. Load
(VOUT = 1.2V; L = 1.5µH)
DC Load Regulation
(VOUT = 1.2V; L = 1.5µH)
100
90
80
70
60
50
40
30
1.0
0.5
VIN = 2.7V
VIN = 5.0V
VIN = 3.6V
VIN = 5.5V
0.0
VIN = 5.5V
VIN = 5.0V
VIN = 4.2V
VIN = 3.6V
VIN = 4.2V
-0.5
-1.0
VIN = 2.7V
0.1
1
10
100
1000
0.1
1
10
100
1000
Output Current (mA)
Output Current (mA)
Soft Start
(VIN = 3.6V; VOUT = 1.8V;
IOUT = 250mA; CFF = 100pF)
Line Regulation
(VOUT = 1.8V)
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
5.0
4.0
3.0
2.0
1.0
0.0
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
-0.4
VEN
IOUT = 0mA
IOUT = 50mA
IOUT = 150mA
-1.0
-2.0
-3.0
-4.0
-5.0
VO
IOUT = 10mA
IOUT = 250mA
IL
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
Time (100µs/div)
Input Voltage (V)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
7
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Typical Characteristics – Step-Down Converter
Output Voltage Error vs. Temperature
(VINB = 3.6V; VOUT = 1.8V; IOUT = 250mA)
Switching Frequency Variation
vs. Temperature
(VIN = 3.6V; VOUT = 1.8V)
3.0
2.0
10.0
8.0
6.0
1.0
4.0
2.0
0.0
0.0
-2.0
-4.0
-6.0
-8.0
-10.0
-1.0
-2.0
-3.0
-40
-20
0
20
40
60
80
100
5.5
6.0
-40
-20
0
20
40
60
80
100
Temperature (°C)
Temperature (°°C)
Frequency Variation vs. Input Voltage
(VOUT = 1.8V)
No Load Quiescent Current vs. Input Voltage
50
45
40
2.0
1.0
0.0
85°C
35
-1.0
-2.0
-3.0
-4.0
30
25°C
25
-40°C
20
15
10
2.7
3.1
3.5
3.9
4.3
4.7
5.1
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
Input Voltage (V)
Input Voltage (V)
P-Channel RDS(ON) vs. Input Voltage
N-Channel RDS(ON) vs. Input Voltage
750
1000
900
800
700
600
500
400
300
700
650
600
550
500
450
400
350
300
120°C 100°C
85°C
120°C
100°C
85°C
25°C
25°C
2.5
3.0
3.5
4.0
4.5
5.0
5.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
Input Voltage (V)
Input Voltage (V)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
8
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Typical Characteristics – Step-Down Converter
Load Transient Response
(10mA to 250mA; VIN = 3.6V; VOUT = 1.8V;
COUT = 4.7µF; CFF = 100pF)
Load Transient Response
(10mA to 250mA; VIN = 3.6V; VOUT = 1.8V; COUT = 4.7µF)
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
VO
VO
IO
IO
ILX
ILX
Time (25µs/div)
Time (25µs/div)
Line Response
(VOUT = 1.8V @ 250mA; CFF = 100pF)
Output Ripple
(VIN = 3.6V; VOUT = 1.8V; IOUT = 1mA)
40
20
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.00
-0.01
1.90
1.85
1.80
1.75
1.70
1.65
1.60
1.55
1.50
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
VO
VO
0
-20
-40
-60
-80
-100
-120
VIN
IL
Time (25µs/div)
Time (2µs/div)
Output Ripple
(VIN = 3.6V; VOUT = 1.8V; IOUT = 250mA)
40
20
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
VO
0
-20
-40
-60
-80
-100
-120
IL
Time (200ns/div)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
9
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Typical Characteristics – Battery Charger
Constant Charging Current
vs. Set Resistor Values
Charging Current vs. Battery Voltage
(VADP = 5V)
600
500
400
300
200
100
0
1000
100
10
RSET = 3.24kΩ
RSET = 5.36kΩ
RSET = 8.06kΩ
RSET = 31.6kΩ
RSET = 16.2kΩ
1
2.7
2.9
3.1
3.3
3.5
3.7
3.9
4.1
4.3
1
10
100
1000
VBAT (V)
RSET (kΩ)
End of Charge Battery Voltage
vs. Supply Voltage
End of Charge Voltage Regulation
vs. Temperature
(RSET = 8.06kΩ)
4.206
4.204
4.202
4.200
4.198
4.196
4.194
4.23
4.22
4.21
4.20
4.19
4.18
4.17
RSET = 8.06kΩ
RSET = 31.6kΩ
4.5
4.75
5
5.25
5.5
5.75
6
6.25
6.5
-50
-25
0
25
50
75
100
VADP (V)
Temperature (°C)
Constant Charging Current vs.
Supply Voltage
Constant Charging Current vs. Temperature
(RSET = 8.06kΩ)
(RSET = 8.06kΩ)
210
208
205
203
200
198
195
193
190
220
210
200
190
180
VBAT = 3.3V
VBAT = 4V
VBAT = 3.6V
170
4
-50
-25
0
25
50
75
100
4.25 4.5 4.75
5
5.25 5.5 5.75
6
6.25 6.5
VADP (V)
Temperature (°C)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
10
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Typical Characteristics – Battery Charger
Operating Current vs. Temperature
(RSET = 8.06kΩ)
Preconditioning Threshold Voltage
vs. Temperature
(RSET = 8.06kΩ)
550
500
450
400
350
300
3.03
3.02
3.01
3
2.99
2.98
2.97
-50
-25
0
25
50
75
100
-50
-25
0
25
50
75
100
Temperature (°C)
Temperature (°C)
Preconditioning Charge Current
vs. Temperature
Preconditioning Charge Current
vs. Supply Voltage
(RSET = 8.06kΩ)
60
20.8
20.6
20.4
20.2
20.0
19.8
19.6
19.4
19.2
RSET = 3.24kΩ
50
40
30
20
10
0
RSET = 5.36kΩ
RSET = 8.06kΩ
RSET = 31.6kΩ
RSET = 16.2kΩ
4
4.2 4.4 4.6 4.8
5
5.2 5.4 5.6 5.8
6
6.2 6.4
-50
-25
0
25
50
75
100
Temperature (°C)
VADP (V)
Recharging Threshold Voltage
vs. Temperature
Sleep Mode Current vs. Supply Voltage
(RSET = 8.06kΩ)
(RSET = 8.06kΩ)
800
700
600
500
400
300
200
100
0
4.18
4.16
4.14
4.12
4.10
4.08
4.06
4.04
4.02
85°C
25°C
-40°C
-50
-25
0
25
50
75
100
4
4.25 4.5 4.75
5
5.25 5.5 5.75
6
6.25 6.5
Temperature (°C)
VADP (V)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
11
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Typical Characteristics – Battery Charger
VEN(H) vs. Supply Voltage
(RSET = 8.06kΩ)
VEN(L) vs. Supply Voltage
(RSET = 8.06kΩ)
1.2
1.1
1
1.1
1
-40°C
-40°C
0.9
0.8
0.7
0.6
0.9
0.8
0.7
25°C
85°C
25°C
85°C
4
4.25 4.5 4.75
5
5.25 5.5 5.75
6
6.25 6.5
4
4.25 4.5
4.75
5
5.25 5.5
5.75
6
6.25 6.5
VADP (V)
VADP (V)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
12
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Typical Characteristics – LDO Regulator
Dropout Voltage vs. Temperature
LDO Dropout Characteristics
(EN = GND; ENLDO = VIN)
540
480
420
360
300
240
180
120
60
3.20
3.00
2.80
2.60
2.40
2.20
2.00
IL = 300mA
IOUT = 0mA
IL = 100mA
IL = 150mA
IOUT = 300mA
IOUT = 150mA
IOUT = 100mA
IOUT = 50mA
IOUT = 10mA
2.80
IL = 50mA
0
-40 -30 -20 -10
0
10 20 30 40 50 60 70 80 90 100 110 120
2.70
2.90
3.00
3.10
3.20
3.30
Temperature (°C)
Input Voltage (V)
Dropout Voltage vs. Output Current
Ground Current vs. Input Voltage
90
80
70
60
50
40
30
20
10
0
500
450
400
350
300
250
200
150
100
50
IOUT = 300mA
85°C
IOUT = 150mA
IOUT = 50mA
25°C
IOUT = 0mA
IOUT = 10mA
-40°C
0
0
50
100
150
200
250
300
2
2.5
3
3.5
4
4.5
5
Input Voltage (V)
Output Current (mA)
Output Voltage vs. Temperature
Quiescent Current vs. Temperature
1.203
1.202
1.201
1.200
1.199
1.198
1.197
1.196
100
90
80
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
-40 -30 -20 -10
0
10 20 30 40 50 60 70 80 90 100
Temperature (°C)
Temperature (°C)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
13
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Typical Characteristics – LDO Regulator
LDO Turn-On Time from Enable
(VIN Present)
LDO Initial Power-Up Response Time
(CBYP = 10nF; EN = GND; ENLDO = VIN)
6
5
4
3
2
1
0
4
3
2
1
0
VENLDO (5V/div)
VOUT (1V/div)
Time (5µs/div)
Time (400µs/div)
Line Transient Response
Turn-Off Response Time
(I = 100mA)
6
5
4
3
2
1
0
3.04
3.03
3.02
3.01
3.00
2.99
2.98
VEN (5V/div)
VIN
VOUT
VOUT (1V/div)
Time (50µs/div)
Time (100µs/div)
Load Transient Response
Load Transient Response 300mA
2.90
2.85
2.80
2.75
2.70
2.65
2.60
500
400
300
200
100
0
3.0
800
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
700
600
500
400
300
200
100
0
VOUT
VOUT
IOUT
IOUT
-100
-100
Time (100µs/div)
Time (10µs/div)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
14
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Typical Characteristics – LDO Regulator
Over-Current Protection
(EN = GND; ENLDO = VIN)
VEN(L) and VEN(H) vs. VIN
1200
1000
800
600
400
200
0
1.250
1.225
1.200
1.175
1.150
1.125
1.100
1.075
1.050
VEN(H)
VEN(L)
-200
2.5
3.0
3.5
4.0
4.5
5.0
5.5
Time (50ms/div)
Input Voltage (V)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
15
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Functional Block Diagram
Reverse Blocking
BAT
ADP
-
-
+
Constant
Current
Charge
Control
ISET
VREF
STAT
Over-
Temperature
Protection
UVLO
EN_BAT
VINB
DH
VINA
LX
Err.
Amp.
Logic
VREF
DL
Over-
Current
Protection
ENB
FB
-
+
VREF
OUTA
ENA
GND
6.5V. The adapter/USB charging current level can be
programmed up to 500mA for rapid charging applica-
tions. A status monitor output pin is provided to indicate
the battery charge state by directly driving one external
LED. Internal device temperature and charging state are
fully monitored for fault conditions. In the event of an
over-voltage or over-temperature failure, the device will
automatically shut down, protecting the charging device,
control system, and the battery under charge. Other
features include an integrated reverse blocking diode
and sense resistor.
Functional Description
The AAT2554 is a high performance power management
IC comprised of a lithium-ion/polymer battery charger, a
step-down converter, and a linear regulator. The linear
regulator is designed for high-speed turn-on and fast
transient response, and good power supply ripple rejec-
tion. The step-down converter operates in both fixed and
variable frequency modes for high efficiency perfor-
mance. The switching frequency is 1.5MHz, minimizing
the size of the inductor. In light load conditions, the
device enters power-saving mode; the switching fre-
quency is reduced and the converter consumes 30μA of
current, making it ideal for battery-operated applications.
Switch-Mode Step-Down Converter
The step-down converter operates with an input voltage
of 2.7V to 5.5V. The switching frequency is 1.5MHz,
minimizing the size of the inductor. Under light load con-
ditions, the device enters power-saving mode; the
switching frequency is reduced, and the converter con-
sumes 30μA of current, making it ideal for battery-
operated applications. The output voltage is program-
Battery Charger
The battery charger is designed for single-cell lithium-
ion/polymer batteries using a constant current and con-
stant voltage algorithm. The battery charger operates
from the adapter/USB input voltage range from 4V to
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
16
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
mable from VIN to as low as 0.6V. Power devices are sized
for 250mA current capability while maintaining over
90% efficiency at full load. Light load efficiency is main-
tained at greater than 80% down to 1mA of load current.
A high-DC gain error amplifier with internal compensa-
tion controls the output. It provides excellent transient
response and load/line regulation.
Protection Circuitry
Over-Voltage Protection
An over-voltage protection event is defined as a condition
where the voltage on the BAT pin exceeds the over-volt-
age protection threshold (VOVP). If this over-voltage con-
dition occurs, the charger control circuitry will shut down
the device. The charger will resume normal charging
operation after the over-voltage condition is removed.
Linear Regulator
The advanced circuit design of the linear regulator has
been specifically optimized for very fast start-up. This
proprietary CMOS LDO has also been tailored for supe-
rior transient response characteristics. These traits are
particularly important for applications that require fast
power supply timing.
Current Limit, Over-Temperature Protection
For overload conditions, the peak input current is limited
at the step-down converter. As load impedance decreas-
es and the output voltage falls closer to zero, more
power is dissipated internally, which causes the internal
die temperature to rise. In this case, the thermal protec-
tion circuit completely disables switching, which protects
the device from damage.
The high-speed turn-on capability is enabled through
implementation of a fast-start control circuit which accel-
erates the power-up behavior of fundamental control
and feedback circuits within the LDO regulator. The LDO
regulator output has been specifically optimized to func-
tion with low-cost, low-ESR ceramic capacitors; however,
the design will allow for operation over a wide range of
capacitor types.
The battery charger has a thermal protection circuit which
will shut down charging functions when the internal die
temperature exceeds the preset thermal limit threshold.
Once the internal die temperature falls below the thermal
limit, normal charging operation will resume.
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.
Control Loop
The AAT2554 contains a compact, current mode step-
downDC/DCcontroller. ThecurrentthroughtheP-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 cur-
rent 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 pro-
grams 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 ter-
minates the transconductance voltage error amplifier
output. The error amplifier reference is fixed at 0.6V.
The regulator features an enable/disable function. This
pin (ENA) is active high and is compatible with CMOS
logic. To assure the LDO regulator will switch on, the ENA
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 ENA pin falls below 0.6V. If the enable
function is not needed in a specific application, it may be
tied to VINA to keep the LDO regulator in a continuously
on state.
Under-Voltage Lockout
The AAT2554 has internal circuits for UVLO and power on
reset features. If the ADP supply voltage drops below the
UVLO threshold, the battery charger will suspend charg-
ing and shut down. When power is reapplied to the ADP
pin or the UVLO condition recovers, the system charge
control will automatically resume charging in the appro-
priate mode for the condition of the battery. If the input
voltage of the step-down converter drops below UVLO,
the internal circuit will shut down.
Battery Charging Operation
Battery charging commences only after checking several
conditions in order to maintain a safe charging environ-
ment. The input supply (ADP) must be above the mini-
mum operating voltage (UVLO) and the enable pin must
be high (internally pulled down). When the battery is
connected to the BAT pin, the charger checks the condi-
tion of the battery and determines which charging mode
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
17
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
to apply. If the battery voltage is below VMIN, the charger
begins battery pre-conditioning by charging at 10% of
the programmed constant current; e.g., if the pro-
grammed current is 150mA, then the pre-conditioning
current (trickle charge) is 15mA. Pre-conditioning is
purely a safety precaution for a deeply discharged cell
and will also reduce the power dissipation in the internal
series pass MOSFET when the input-output voltage dif-
ferential is at its highest.
the battery voltage reaches VBAT, the battery charger
begins constant voltage mode. The regulation voltage is
factory programmed to a nominal 4.2V (±0.5%) and will
continue charging until the charging current has reduced
to 10% of the programmed current.
After the charge cycle is complete, the pass device turns
off and the device automatically goes into a power-sav-
ing sleep mode. During this time, the series pass device
will block current in both directions, preventing the bat-
tery from discharging through the IC.
Pre-conditioning continues until the battery voltage
reaches VMIN (see Figure 1). At this point, the charger
begins constant-current charging. The current level for
this mode is programmed using a single resistor from
the ISET pin to ground. Programmed current can be set
from a minimum 15mA up to a maximum of 500mA.
Constant current charging will continue until the battery
voltage reaches the voltage regulation point, VBAT. When
The battery charger will remain in sleep mode, even if
the charger source is disconnected, until one of the fol-
lowing events occurs: the battery terminal voltage drops
below the VRCH threshold; the charger EN pin is recycled;
or the charging source is reconnected. In all cases, the
charger will monitor all parameters and resume charging
in the most appropriate mode.
Preconditioning
Trickle Charge
Phase
Constant Current
Charge Phase
Constant Voltage
Charge Phase
Charge Complete Voltage
Regulated Current
I = Max CC
Constant Current Mode
Voltage Threshold
Trickle Charge and
Termination Threshold
I = CC / 10
Figure 1: Current vs. Voltage Profile During Charging Phases.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
18
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Battery Charging System Operation Flow Chart
Enable
Yes
Power On Reset
No
Power Input
Voltage
VADP > VUVLO
Yes
Fault Conditions
Monitoring
OV, OT
Charge
Control
Shutdown
Yes
No
Preconditioning
Test
Preconditioning
(Trickle Charge)
Yes
V
MIN > VBAT
No
No
Constant
Current Charge
Mode
Recharge Test
Current Phase Test
ADP > VBAT
Yes
Yes
V
RCH > VBAT
V
No
Constant
Voltage Charge
Mode
Voltage Phase Test
IBAT > ITERM
Yes
No
Charge Completed
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
19
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
reason, a 1% tolerance metal film resistor is recom-
mended for the set resistor function. Fast charge con-
stant current levels from 15mA to 500mA may be set by
selecting the appropriate resistor value from Table 1.
Application Information
Soft Start / Enable
The EN_BAT pin is internally pulled down. When pulled
to a logic high level, the battery charger is enabled.
When left open or pulled to a logic low level, the battery
charger is shut down and forced into the sleep state.
Charging will be halted regardless of the battery voltage
or charging state. When it is re-enabled, the charge con-
trol circuit will automatically reset and resume charging
functions with the appropriate charging mode based on
the battery charge state and measured cell voltage from
the BAT pin.
Normal ICHARGE (mA) Set Resistor Value R1 (k)
500
400
300
250
200
150
100
50
40
30
20
15
3.24
4.12
5.36
6.49
8.06
10.7
16.2
31.6
38.3
53.6
78.7
105
Separate ENA and ENB inputs are provided to indepen-
dently enable and disable the LDO and step-down con-
verter, respectively. This allows sequencing of the LDO
and step-down outputs during startup.
Table 1: RSET Values.
The LDO is enabled when the ENA pin is pulled high. The
control and feedback circuits have been optimized for
high-speed, monotonic turn-on characteristics.
1000
100
10
The step-down converter is enabled when the ENB pin is
pulled high. Soft start increases the inductor current
limit point in discrete steps when the input voltage or
ENB input is applied. It limits the current surge seen at
the input and eliminates output voltage overshoot. When
pulled low, the ENB input forces the AAT2554 into a low-
power, non-switching state. The total input current dur-
ing shutdown is less than 1μA.
1
1
10
100
1000
RSET (kΩ)
Adapter or USB Power Input
Figure 2: Constant Charging Current
vs. Set Resistor Values.
Constant current charge levels up to 500mA may be
programmed by the user when powered from a sufficient
input power source. The battery charger will operate
from the adapter input over a 4.0V to 6.5V range. The
constant current fast charge current for the adapter
input is set by the RSET resistor connected between ISET
and ground. Refer to Table 1 for recommended RSET val-
ues for a desired constant current charge level.
Charge Status Output
The AAT2554 provides battery charge status via a status
pin. This pin is internally connected to an N-channel
open drain MOSFET, which can be used to drive an exter-
nal LED. The status pin can indicate several conditions,
as shown in Table 2.
Programming Charge Current
Event Description
Status
The fast charge constant current charge level is user
programmed with a set resistor placed between the ISET
pin and ground. The accuracy of the fast charge, as well
as the preconditioning trickle charge current, is domi-
nated by the tolerance of the set resistor used. For this
No battery charging activity
Battery charging via adapter
Charging completed
OFF
ON or USB port
OFF
Table 2: LED Status Indicator.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
20
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
The LED should be biased with as little current as neces-
sary to create reasonable illumination; therefore, a bal-
last resistor should be placed between the LED cathode
and the STAT pin. LED current consumption will add to
the overall thermal power budget for the device pack-
age, hence it is good to keep the LED drive current to a
minimum. 2mA should be sufficient to drive most low-
cost green or red LEDs. It is not recommended to exceed
8mA for driving an individual status LED.
Figure 3 shows the relationship of maximum power dis-
sipation and ambient temperature of the AAT2554.
3000
2500
2000
1500
1000
500
The required ballast resistor values can be estimated
using the following formulas:
0
0
20
40
60
80
100
120
(VADP
- VF(LED)
ILED
)
R1=
TA (°C)
Figure 3: Maximum Power Dissipation.
Example:
Next, the power dissipation of the battery charger can
be calculated by the following equation:
(5.5V - 2.0V)
2mA
R1 =
= 1.75kΩ
Note: Red LED forward voltage (VF) is typically 2.0V @
2mA.
PD = [(VADP - VBAT) · ICH + (VADP · IOP)]
Where:
Thermal Considerations
PD = Total Power Dissipation by the Device
VADP = ADP/USB Voltage
VBAT = Battery Voltage as Seen at the BAT Pin
ICH = Constant Charge Current Programmed for the
Application
The AAT2554 is offered in a TDFN34-16 package which
can provide up to 2W of power dissipation when it is
properly bonded to a printed circuit board and has a
maximum thermal resistance of 50°C/W. Many consider-
ations should be taken into account when designing the
printed circuit board layout, as well as the placement of
the charger IC package in proximity to other heat gener-
ating devices in a given application design. The ambient
temperature around the IC will also have an effect on the
thermal limits of a battery charging application. The
maximum limits that can be expected for a given ambi-
ent condition can be estimated by the following discus-
sion.
IOP = Quiescent Current Consumed by the Charger IC for
Normal Operation [0.5mA]
By substitution, we can derive the maximum charge cur-
rent before reaching the thermal limit condition (thermal
cycling). The maximum charge current is the key factor
when designing battery charger applications.
(PD(MAX)
-
VIN
VIN - VBAT
· IOP)
ICH(MAX)
=
First, the maximum power dissipation for a given situa-
tion should be calculated:
(TJ(MAX)
θJA
VIN - VBAT
- TA)
-
VIN · IOP
(TJ(MAX) - TA)
θJA
PD(MAX)
=
ICH(MAX)
=
Where:
In general, the worst condition is the greatest voltage
drop across the IC, when battery voltage is charged up
to the preconditioning voltage threshold. Figure 4 shows
the maximum charge current in different ambient tem-
peratures.
PD(MAX) = Maximum Power Dissipation (W)
JA = Package Thermal Resistance (°C/W)
TJ(MAX) = Maximum Device Junction Temperature (°C)
[135°C]
TA = Ambient Temperature (°C)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
21
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Capacitor Selection
500
400
300
200
100
0
Linear Regulator Input Capacitor (C7)
TA = 60°C
An input capacitor greater than 1μF will offer superior
input line transient response and maximize power supply
ripple rejection. Ceramic, tantalum, or aluminum elec-
trolytic capacitors may be selected for CIN. There is no
specific capacitor ESR requirement for CIN. However, for
300mA LDO regulator output operation, ceramic capaci-
tors are recommended for CIN due to their inherent capa-
bility over tantalum capacitors to withstand input current
surges from low impedance sources such as batteries in
portable devices.
TA = 85°C
4.25 4.5 4.75
5
5.25 5.5 5.75
6
6.25 6.5 6.75
VIN (V)
Figure 4: Maximum Charging Current Before
Thermal Cycling Becomes Active.
Battery Charger Input Capacitor (C3)
In general, it is good design practice to place a decou-
pling capacitor between the ADP pin and GND. An input
capacitor in the range of 1μF to 22μF is recommended.
If the source supply is unregulated, it may be necessary
to increase the capacitance to keep the input voltage
above the under-voltage lockout threshold during device
enable and when battery charging is initiated. If the
adapter input is to be used in a system with an external
power supply source, such as a typical AC-to-DC wall
adapter, then a CIN capacitor in the range of 10μF should
be used. A larger input capacitor in this application will
minimize switching or power transient effects when the
power supply is “hot plugged” in.
There are three types of losses associated with the step-
down converter: switching losses, conduction losses, and
quiescent current losses. Conduction losses are associ-
ated 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 losses is given by:
IO2 · (RDSON(H) · VO + RDSON(L) · [VIN - VO])
PTOTAL
=
VIN
+ (tsw · FS · IO + IQ) · VIN
Step-Down Converter Input Capacitor (C1)
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 CIN. The calculated value varies with input volt-
age and is a maximum when VIN is double the output
voltage.
IQ is the step-down converter quiescent current. The
term tsw is used to estimate the full load step-down con-
verter switching losses.
For the condition where the step-down converter is in
dropout at 100% duty cycle, the total device dissipation
reduces to:
VO
VIN
⎛
VO ⎞
VIN ⎠
· 1 -
⎝
PTOTAL = IO2 · RDSON(H) + IQ · VIN
CIN =
⎛ VPP
⎝ IO
⎞
- ESR ·FS
⎠
Since RDS(ON), quiescent current, and switching losses all
vary with input voltage, the total losses should be inves-
tigated over the complete input voltage range.
VO
VIN
⎛
VO ⎞
VIN ⎠
1
· 1 -
⎝
=
for VIN = 2 · VO
4
Given the total losses, the maximum junction tempera-
ture can be derived from the JA for the TDFN34-16 pack-
age which is 50°C/W.
1
CIN(MIN)
=
⎛ VPP
⎝ IO
⎞
⎠
- ESR · 4 · FS
TJ(MAX) = PTOTAL · ΘJA + TAMB
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
22
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Always examine the ceramic capacitor DC voltage coef-
ficient 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.
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 induc-
tance cannot be reduced to a level that does not affect
the converter performance, a high ESR tantalum or alu-
minum electrolytic capacitor should be placed in parallel
with the low ESR, ESL bypass ceramic capacitor. This
dampens the high Q network and stabilizes the system.
The maximum input capacitor RMS current is:
VO
VIN
⎛
VO ⎞
VIN ⎠
IRMS = IO ·
· 1 -
⎝
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.
Linear Regulator Output Capacitor (C6)
For proper load voltage regulation and operational sta-
bility, 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 rec-
ommended for best performance. Applications utilizing
the exceptionally low output noise and optimum power
supply ripple rejection should use 2.2μF or greater for
VO
VIN
⎛
VO ⎞
VIN ⎠
1
2
· 1 -
⎝
=
D · (1 - D) = 0.52 =
for VIN = 2 · VO
IO
IRMS(MAX)
=
2
C
OUT. In low output current applications, where output
VO
·
VO
1 -
load is less than 10mA, the minimum value for COUT can
be as low as 0.47μF.
The term
appears in both the input voltage
VIN
VIN
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.
Battery Charger Output Capacitor (C5)
The AAT2554 only requires a 1μF ceramic capacitor on
the BAT pin to maintain circuit stability. This value
should be increased to 10μF or more if the battery con-
nection is made any distance from the charger output. If
the AAT2554 is to be used in applications where the bat-
tery can be removed from the charger, such as with
desktop charging cradles, an output capacitor greater
than 10μF may be required to prevent the device from
cycling on and off when no battery is present.
The input capacitor provides a low impedance loop for
the edges of pulsed current drawn by the step-down
converter. 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.
Step-Down Converter Output Capacitor (C4)
The proper placement of the input capacitor (C1) can be
seen in the evaluation board layout in Figure 6.
The output capacitor limits the output ripple and pro-
vides holdup during large load transitions. A 4.7μF to
10μF X5R or X7R ceramic capacitor typically provides
sufficient bulk capacitance to stabilize the output during
large load transitions and has the ESR and ESL charac-
teristics necessary for low output ripple. For enhanced
transient response and low temperature operation appli-
cations, a 10μF (X5R, X7R) ceramic capacitor is recom-
mended to stabilize extreme pulsed load conditions.
A laboratory test set-up typically consists of two long
wires running from the bench power supply to the eval-
uation 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 dur-
ing load transients. Errors in the loop phase and gain
measurements can also result.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
23
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
The output voltage droop due to a load transient is dom-
inated 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 volt-
age droop during the three switching cycles to the output
capacitance can be estimated by:
For most designs, the step-down converter operates with
inductor values from 1μH to 4.7μH. Table 3 displays
inductor values for the AAT2554 for various output volt-
ages.
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 satura-
tion 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.
3 · ΔILOAD
=
COUT
V
DROOP · FS
Once the average inductor current increases to the DC
load level, the output voltage recovers. The above equa-
tion establishes a limit on the minimum value for the
output capacitor with respect to load transients.
The 3.0μH CDRH2D09 series inductor selected from
Sumida has a 150m DCR and a 470mA DC current rat-
ing. At full load, the inductor DC loss is 9.375mW which
gives a 2.08% loss in efficiency for a 250mA, 1.8V out-
put.
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 capac-
itance will reduce the crossover frequency with greater
phase margin.
Output Voltage (V)
L1 (μH)
1.0
1.2
1.5
1.8
2.5
3.0
3.3
1.5
2.2
2.7
3.0/3.3
3.9/4.2
4.7
The maximum output capacitor RMS ripple current is
given by:
1
V
OUT · (VIN(MAX) - VOUT
)
IRMS(MAX)
=
·
L · FS · VIN(MAX)
2 · 3
5.6
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.
Table 3: Step-Down Converter Inductor Values.
Adjustable Output Resistor Selection
Inductor Selection
Resistors R2 and R3 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 suggested
value for R3 is 59k. Decreased resistor values are nec-
essary to maintain noise immunity on the FB pin, result-
ing in increased quiescent current. Table 4 summarizes
the resistor values for various output voltages.
The step-down converter uses peak current mode con-
trol 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 AAT2554 is
0.45A/μsec. This equates to a slope compensation that
is 75% of the inductor current down slope for a 1.8V
output and 3.0μH inductor.
V
V
3.3V
0.6V
⎛
⎝
⎞
⎛
⎝
⎞
⎠
R2 =
OUT -1 · R3 =
- 1 · 59kΩ = 267kΩ
⎠
REF
0.75 ⋅ VO 0.75 ⋅ 1.8V
= 0.45
A
µsec
m =
=
L
3.0µH
With enhanced transient response for extreme pulsed
load application, an external feed-forward capacitor (C8
in Figure 5) can be added.
0.75 ⋅ VO
0.75
⋅
VO
A
µsec
A
L =
=
≈
1.67
⋅ VO
m
0.45A
µsec
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
24
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
VINB
VINB
ADP
C1
4.7μF
U1
VBAT
ADP
16
11
9
8
1
2
VINB
BAT
5
VOUTA
L1
R4
1K
ADP
STAT
VINA
ENA
ENB
OUTA
LX
C3
4.7μF
VOUTA
VOUTB
C8
15
1
VOUTB
D1
4
FB
R2
118K
ENA
13
3
14
12
10
2
R5
C4
4.7μF
GND
GND
VINB
100K
VINA
100pF
C7
2.2μF
FB
JP2
6
C6
2.2μF
C5
2.2μF
R3
59K
R6
100K
JP3
C8 optional for
enhanced step-
down converter
transient
3
2
1
EN_BAT GND
ADP
7
ISET
GND
response
ENA
R7
100K
JP1
3
2
1
AAT2554
R1
8.06K
ENB
ENB
3
2
1
EN_BAT
GND
EN_BAT
Figure 5: AAT2554 Evaluation Board Schematic.
example (see Figures 6 and 7). The following guidelines
should be used to help ensure a proper layout.
R3 = 59k
R2 (k)
R3 = 221k
R2 (k)
VOUT (V)
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
1. The input capacitors (C1, C3, C7) should connect as
closely as possible to ADP (Pin 11), VINA (Pin 4),
and VINB (Pin 16).
2. C4 and L1 should be connected as closely as possi-
ble. The connection of L1 to the LX pin should be as
short as possible. Do not make the node small by
using narrow trace. The trace should be kept wide,
direct, and short.
3. The feedback pin (Pin 1) 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. Feedback
resistors should be placed as closely as possible to
the FB pin (Pin 1) 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 GND
(Pins 2, 10, 12, and 14) should be kept to a mini-
mum. 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. A high density, small footprint layout can be achieved
using an inexpensive, miniature, non-shielded, high
DCR inductor.
Table 4: Adjustable Resistor Values For
Step-Down Converter.
Printed Circuit Board
Layout Considerations
For the best results, it is recommended to physically
place the battery pack as close as possible to the
AAT2554 BAT pin. To minimize voltage drops on the PCB,
keep the high current carrying traces adequately wide.
Refer to the AAT2554 evaluation board for a good layout
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
25
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Figure 6: AAT2554 Evaluation Board
Top Side Layout.
Figure 7: AAT2554 Evaluation Board
Bottom Side Layout.
Component
Part Number
Description
Manufacturer
U1
C1, C3, C4
C5, C6, C7
AAT2554IRN-T1
GRM188R60J475KE19
GRM188R61A225KE34
GRM1886R1H101JZ01J
CDRH2D09-3R0
Chip Resistor
Total Power Solution for Portable Applications
Ceramic 4.7μF 6.3V X5R 0603
Ceramic 2.2μF 10V X5R 0603
Ceramic 100pF 50V 5% R2H 0603
Shielded SMD, 3.0μH, 150m, 3x3x1mm
1k, 5%, 1/4W; 0603
Skyworks
Murata
Murata
Murata
Sumida
C8
L1
R4
Vishay
R1
R2
Chip Resistor
Chip Resistor
8.06k, 1%, 1/4W; 0603
118k, 1%, 1/4W; 0603
Vishay
Vishay
R3
Chip Resistor
59k, 1%, 1/4W; 0603
Vishay
R5, R6, R7
JP1, JP2, JP3
D1
Chip Resistor
PRPN401PAEN
CMD15-21SRC/TR8
100k, 5%, 1/8W; 0402
Connecting Header, 2mm zip
Red LED; 1206
Vishay
Sullins Electronics
Chicago Miniature Lamp
Table 5: AAT2554 Evaluation Board Component Listing.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
26
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Step-Down Converter Design Example
Specifications
VO =1.8V @ 250mA, Pulsed Load ILOAD = 200mA
VIN = 2.7V to 4.2V (3.6V nominal)
FS = 1.5MHz
TAMB = 85°C
1.8V Output Inductor
µsec
A
µsec
(use 3.0μH; see Table 3)
⋅ 1.8V = 3µH
A
L1 = 1.67
⋅ VO2 = 1.67
For Sumida inductor CDRH2D09-3R0, 3.0μH, DCR = 150m.
⎛
⎞
⎠
VO
L1 ⋅ FS
VO
VIN
1.8
V
1.8V
4.2V
⎛
⎞
⎠
ΔIL1 =
⋅ 1 -
⎝
=
⋅ 1 -
= 228mA
⎝
3.0µH ⋅ 1.5MHz
ΔIL1
2
IPKL1 = IO +
= 250mA + 114mA = 364mA
2
PL1 = IO ⋅ DCR = 250mA2 ⋅ 150mΩ = 9.375mW
1.8V Output Capacitor
VDROOP = 0.1V
3 · ΔILOAD
VDROOP · FS
3 · 0.2A
COUT
=
=
= 4µF (use 4.7µF)
0.1V · 1.5MHz
(VO) · (VIN(MAX) - VO)
L1 · FS · VIN(MAX)
1
1.8V · (4.2V - 1.8V)
1
·
= 66mArms
IRMS
=
·
=
3.0µH · 1.5MHz · 4.2V
2· 3
2· 3
Pesr = esr · IRMS2 = 5mΩ · (66mA)2 = 21.8µW
Input Capacitor
Input Ripple VPP = 25mV
1
1
CIN =
=
= 1.38µF (use 4.7µF)
⎛ VPP
⎝ IO
⎞
⎛ 25mV
⎝ 0.2A
⎞
⎠
- ESR · 4 · FS
- 5mΩ · 4 · 1.5MHz
⎠
IO
IRMS
=
= 0.1Arms
2
P = esr · IRMS2 = 5mΩ · (0.1A)2 = 0.05mW
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
27
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
AAT2554 Losses
IO2 · (RDSON(H) · VO + RDSON(L) · [VIN -VO])
PTOTAL
=
VIN
+ (tsw · FS · IO + IQ) · VIN
0.22 · (0.59Ω · 1.8V + 0.42Ω · [4.2V - 1.8V])
4.2V
=
+ (5ns · 1.5MHz · 0.2A + 30µA) · 4.2V = 26.14mW
TJ(MAX) = TAMB + ΘJA · PLOSS = 85°C + (50°C/W) · 26.14mW = 86.3°C
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
28
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
VOUT (V)
R2 (k)
R2 (k)
L1 (μH)
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
0
0
75
1.5
1.5
1.5
1.5
1.5
1.5
1.5
2.2
2.7
3.0/3.3
3.0/3.3
3.0/3.3
3.9/4.2
5.6
19.6
29.4
39.2
49.9
59.0
68.1
78.7
88.7
118
124
137
187
267
113
150
187
221
261
301
332
442
464
523
715
1000
Table 6: Step-Down Converter Component Values.
Max DC
Current (mA)
Size (mm)
LxWxH
Manufacturer
Part Number
Inductance (μH)
DCR (m)
Type
Sumida
Sumida
Sumida
Sumida
Sumida
Sumida
Sumida
Sumida
Sumida
Sumida
Sumida
Taiyo Yuden
Taiyo Yuden
Taiyo Yuden
Taiyo Yuden
FDK
CDRH2D09-1R5
CDRH2D09-2R2
CDRH2D09-2R5
CDRH2D09-3R0
CDRH2D09-3R9
CDRH2D09-4R7
CDRH2D09-5R6
CDRH2D11-1R5
CDRH2D11-2R2
CDRH2D11-3R3
CDRH2D11-4R7
NR3010T1R5N
NR3010T2R2M
NR3010T3R3M
NR3010T4R7M
MIPWT3226D-1R5
MIPWT3226D-2R2
MIPWT3226D-3R0
MIPWT3226D-4R2
1.5
2.2
2.5
3.0
3.9
4.7
5.6
1.5
2.2
3.3
4.7
1.5
2.2
3.3
4.7
1.5
2.2
3.0
4.2
730
600
530
470
450
410
370
900
780
600
500
1200
1100
870
750
1200
1100
1000
900
110
144
150
194
225
287
325
68
3.0x3.0x1.0
3.0x3.0x1.0
3.0x3.0x1.0
3.0x3.0x1.0
3.0x3.0x1.0
3.0x3.0x1.0
3.0x3.0x1.0
3.2x3.2x1.2
3.2x3.2x1.2
3.2x3.2x1.2
3.2x3.2x1.2
3.0x3.0x1.0
3.0x3.0x1.0
3.0x3.0x1.0
3.0x3.0x1.0
3.2x2.6x0.8
3.2x2.6x0.8
3.2x2.6x0.8
3.2x2.6x0.8
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Shielded
Chip shielded
Chip shielded
Chip shielded
Chip shielded
98
123
170
80
95
140
190
90
100
120
140
FDK
FDK
FDK
Table 7: Suggested Inductors and Suppliers.
Manufacturer
Part Number
Value (μF)
Voltage Rating
Temp. Co.
Case Size
Murata
Murata
Murata
Murata
Murata
Murata
GRM21BR61A106KE19
GRM188R60J475KE19
GRM188R61A225KE34
GRM188R60J225KE19
GRM188R61A105KA61
GRM185R60J105KE26
10
10
6.3
10
6.3
10
X5R
X5R
X5R
X5R
X5R
X5R
0805
0603
0603
0603
0603
0603
4.7
2.2
2.2
1.0
1.0
6.3
Table 8: Surface Mount Capacitors.
1. For reduced quiescent current, R3 = 221k.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
29
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Ordering Information
Package
Marking1
Part Number (Tape and Reel)2
TDFN34-16
TDFN34-16
TDFN34-16
RZXYY
SAXYY
TOXYY
AAT2554IRN-CAP-T1
AAT2554IRN-CAT-T1
AAT2554IRN-CAW-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)
A
B
E
G
I
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
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.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
30
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
DATA SHEET
AAT2554
Total Power Solution for Portable Applications
Package Information1
TDFN34-16
1.600 0.050
R0.15 (REF)
Pin 1 ID
3.000 0.050
Index Area
0.25 REF
0.430 0.050
1.600 0.050
Top View
Bottom View
+ 0.100
0
0.230 0.050
-0.000
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.
Copyright © 2012, 2013 Skyworks Solutions, Inc. All Rights Reserved.
Information in this document is provided in connection with Skyworks Solutions, Inc. (“Skyworks”) products or services. These materials, including the information contained herein, are provided by Skyworks as a
service to its customers and may be used for informational purposes only by the customer. Skyworks assumes no responsibility for errors or omissions in these materials or the information contained herein. Sky-
works may change its documentation, products, services, specifications or product descriptions at any time, without notice. Skyworks makes no commitment to update the materials or information and shall have no
responsibility whatsoever for conflicts, incompatibilities, or other difficulties arising from any future changes.
No license, whether express, implied, by estoppel or otherwise, is granted to any intellectual property rights by this document. Skyworks assumes no liability for any materials, products or information provided here-
under, including the sale, distribution, reproduction or use of Skyworks products, information or materials, except as may be provided in Skyworks Terms and Conditions of Sale.
THE MATERIALS, PRODUCTS AND INFORMATION ARE PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, INCLUDING FITNESS FOR A PARTICULAR
PURPOSE OR USE, MERCHANTABILITY, PERFORMANCE, QUALITY OR NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHT; ALL SUCH WARRANTIES ARE HEREBY EXPRESSLY DISCLAIMED. SKYWORKS DOES
NOT WARRANT THE ACCURACY OR COMPLETENESS OF THE INFORMATION, TEXT, GRAPHICS OR OTHER ITEMS CONTAINED WITHIN THESE MATERIALS. SKYWORKS SHALL NOT BE LIABLE FOR ANY DAMAGES, IN-
CLUDING BUT NOT LIMITED TO ANY SPECIAL, INDIRECT, INCIDENTAL, STATUTORY, OR CONSEQUENTIAL DAMAGES, INCLUDING WITHOUT LIMITATION, LOST REVENUES OR LOST PROFITS THAT MAY RESULT FROM
THE USE OF THE MATERIALS OR INFORMATION, WHETHER OR NOT THE RECIPIENT OF MATERIALS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 en-
vironmental 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
use or sale.
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 pub-
lished 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
design, or damage to any equipment resulting from the use of Skyworks products outside of stated published specifications or parameters.
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
identification purposes only, and are the property of their respective owners. Additional information, including relevant terms and conditions, posted at www.skyworksinc.com, are incorporated by reference.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
31
202176B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013
相关型号：
©2020 ICPDF网 联系我们和版权申明