ANALOGICTECH AAT2603INJ-1-T1

PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
General Description
Features
The AAT2603 is a highly integrated power management
solution for handheld mobile systems. It provides six
regulated voltages from a single-cell Lithium-ion/polymer battery or a 5V supply.
• VIN Range: 2.7V to 5.5V
• Two Step-Down Regulators
▪ DC-DC1(Buck1): 1.2A, Low Dropout Voltage
• Externally Adjustable: VFBB1 = 0.6V
▪ VOUT Range: 0.6V to VINB1
• Fixed: VOUT = 3.3V
▪ Factory Programmable to any Two Voltage
Levels from 0.6V to 4.0V
• DC-DC2(Buck2): 0.6A, Low Dropout Voltage
• Externally Adjustable: VFBB2 = 0.6V
▪ VOUT Range: 0.6V to VINB2
• Fixed: VOUT = 1.0V[SELB2=’0’]/1.3V[SELB2=’1’]
▪ Factory Programmable to any Two Voltage
Levels from 0.6V to 4.0V
Fixed
1.5MHz Switching Frequency
▪
Internally
Compensated Current Mode Control
▪
High
Efficiency
over the Entire Load Range
▪
Four
LDO
Regulators
▪
• LDO1: 400mA LDO
• LDO2: 400mA LDO
• LDO3: 200mA, Low Noise LDO
• LDO4: 200mA, Low Noise LDO
• Fast Turn-On and Turn-Off time
• Short Circuit and Over-Current Protection
• Over-Temperature Protection
• Temperature Range: -40°C to +85°C
• TQFN44-28 Package
The six outputs are produced by six regulators; two
switching step-down regulators and four low-dropout
(LDO) regulators. Each voltage regulator has its own
independent enable pin.
The high efficiency step-down regulators are fully integrated and switch at a high 1.5 MHz fixed frequency.
They automatically transition to variable frequency
operation at light loads for improved efficiency. DC-DC1
(Buck1) is designed for high output current and low
dropout voltage (200mV at 1.2A). DC-DC2 (Buck2) is a
600mA regulator with a two step dynamic output voltage
capability. One option allows the output voltage of
DC-DC2 (Buck2) to be set to either 1.0V or 1.3V with the
SELB2 logic pin.
LDO regulators LDO1 and LDO2 can supply up to 400mA
of load current with output voltages adjustable down to
1.5V. LDO regulators LDO3 and LDO4 can supply up to
200mA of current and provide good noise and power supply rejection. LDO3 and LDO4 have output voltages externally adjustable down to 1.2V.
The AAT2603 is available in a Pb-free thermally enhanced
28-pin TQFN44 package and is rated for operation over
the -40°C to +85°C temperature range.
Applications
•
•
•
•
•
2603.2008.06.1.0
Handheld GPS
Handheld Instruments
PDAs and Handheld Computers
Portable Media Players
Smart Phones
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1
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Typical Application Circuit
2.7V to 5.5V
L1
3.3μH
INB1
3.3V: 1.2A
LX1
C INB1
4.7μF
C OUTB1
22μF
FBB 1
INB2
L2
1.2μH
CINB2
4.7μF
1.0V & 1.3V: 600mA
LX2
AIN
COUTB2
10μF
FBB 2
CAIN
2.2μF
1.5V (Minimum): 400mA
OUTL1
INL 12
C INL12
2.2μF
C OUTL1
4.7μF
FBL 1
100kΩ
INL 34
AAT2603
OUTL2
CINL34
2.2μF
1.5V (Minimum): 400mA
C OUTL2
4.7μF
FBL 2
ENB1
100kΩ
ENB2
C OUTL3
4.7μF
ENL 2
FBL3
100kΩ
ENL 3
ENL 4
2
C OUTL4
4.7μF
FBL4
100kΩ
BYP
AGND
1.2V (Minimum): 200mA
OUTL4
SELB 2
C BYP
10nF
1.2V (Minimum): 200mA
OUTL3
ENL 1
PGND 1
PGND2
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2603.2008.06.1.0
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Pin Descriptions
Pin #
Symbol
1
LX2
2
ENB2
3
FBB2
4
5
ENL3
AGND
6
FBL3
7
8
9
OUTL3
INL34
OUTL4
10
FBL4
11
ENL4
12
BYP
13
ENL1
14
FBL1
15
16
17
OUTL1
INL12
OUTL2
18
FBL2
19
ENL2
20
AIN
21
FBB1
22
23
ENB1
SELB2
24
LX1
25
PGND1
26
INB1
27
INB2
28
PGND2
EP
2603.2008.06.1.0
Function
DC-DC2 (Buck2) switching node. Connect the output inductor to LX2. Connected internally to the
drains o f both high-side and low-side switches.
DC-DC2 (Buck2) enable input. Active high.
DC-DC2 (Buck2) feedback input. For externally adjustable versions, connect a resistor divider
from Buck2 output to FBB2 to AGND to set the Buck2 output voltage.
LDO3 enable input. Active high.
Analog ground. Connect AGND to PGND1 and PGND2 as close as possible to the device.
LDO3 feedback input. Connect a resistor divider from OUTL3 to FBL3 to AGND to set the LDO3
output voltage.
LDO3 output. Should be closely decoupled to AGND with a 4.7μF or greater capacitor.
LDO3 and LDO4 input. Should be closely decoupled to AGND with a 2.2μF or greater capacitor.
LDO4 output. Should be closely decoupled to AGND with a 4.7μF or greater capacitor.
LDO4 feedback input. Connect a resistor divider from OUTL4 to FBL4 to AGND to set the LDO4
output voltage.
LDO4 enable input. Active high.
Reference Bypass. Bypass BYP to AGND with a 0.01μF or greater capacitor to reduce the LDO1
output noise.
LDO1 enable input. Active high.
LDO1 feedback input. Connect a resistor divider from OUTL1 to FBL1 to AGND to set the LDO1
output voltage.
LDO1 output. Should be closely decoupled to AGND with a 4.7μF or greater capacitor.
LDO1 and LDO2 input. Should be closely decoupled to AGND with a 2.2μF or greater capacitor.
LDO2 output. Should be closely decoupled to AGND with a 4.7μF or greater capacitor.
LDO2 feedback input. Connect a resistor divider from OUTL2 to FBL2 to AGND to set the LDO2
output voltage.
LDO2 enable input. Active high.
Analog voltage input. AIN is the bias supply for the device. Should be closely decoupled to AGND
with a 2.2μF or greater capacitor.
DC-DC1 (Buck1) feedback input. For externally adjustable versions, connect a resistor divider
from Buck1 output to FBB1 to AGND to set the Buck1 output voltage.
DC-DC1 (Buck1) enable input. Active high.
Dynamically adjusts the output voltage of DC-DC2 (Buck2) (Logic High=1.3V, Logic Low=1.0V)
DC-DC1 (Buck1) switching node. Connect the output inductor to LX1. Connected internally to the
drains of both high-side and low-side switches.
DC-DC1 (Buck1) power ground. Connected internally to the source of the Buck1 N-channel synchronous rectifier. Connect PGND1 to PGND2 and AGND as close as possible to the device.
DC-DC1 (Buck1) power input. Connected internally to the source of the Buck1 P-channel switch.
Should be closely decoupled to PGND1 with a 4.7μF or greater capacitor.
DC-DC2 (Buck2) power input. Connected internally to the source of the Buck2 P-channel switch.
Should be closely decoupled to PGND2 with a 4.7μF or greater capacitor.
DC-DC2 (Buck2) power ground. Connected internally to the source of the Buck2 N-channel synchronous rectifier. Connect PGND2 to PGND1 and AGND as close as possible to the device.
Exposed paddle (bottom). Connect to ground as close as possible to the device.
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PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Pin Configuration
TQFN44-28
(Top View)
ENB1
SELB2
LX1
PGND1
INB1
INB2
PGND2
28
LX2
ENB2
FBB2
ENL3
AGND
FBL3
OUTL3
27
26
25
24
23
22
1
21
2
20
3
19
EP
4
18
5
17
6
16
7
15
8
9
10
11
12
13
FBB1
AIN
ENL2
FBL2
OUTL2
INL12
OUTL1
14
FBL1
ENL1
BYP
ENL4
FBL4
OUTL4
INL34
Part Number Descriptions
Output Voltage1
Part Number
DC-DC1 (Buck1)
DC-DC2 (Buck2)
(SELB2 = Low)
DC-DC2 (Buck2)
(SELB2 = High)
LDOs 1-4
AAT2603INJ-1-T1
AAT2603INJ-2-T1
AAT2603INJ-3-T1
Ext. Adj. (VFBB1 = 600mV)
3.3V
Ext. Adj. (VFBB1 = 600mV)
Ext. Adj. (VFBB2 = 600mV)
1.0V
1.0V
Ext. Adj. (VFBB2 = 775mV)
1.3V
1.3V
Ext. Adj. (VFBLX = 1.2V)
Ext. Adj. (VFBLX = 1.2V)
Ext. Adj. (VFBLX = 1.2V)
Absolute Maximum Ratings1
TA = 25°C unless otherwise noted.
Symbol
Description
INBX, INLXX, AIN to AGND
ENBX, ENLX, FBBX, FBLX, BYP to AGND
LX1 to PGND1
LX2 to PGND2
PGNDX to AGND, PGND1 to PGND2
Operating Temperature Range
Storage Temperature Range
Maximum Soldering Temperature (at leads, 10 sec)
Value
Units
-0.3 to 6.0
-0.3 to VAIN+0.3
-0.3 to VINB1+0.3
-0.3 to VINB2+0.3
-0.3 to 0.3
-40 to 150
-65 to 150
300
V
V
V
V
V
°C
°C
°C
Value
Units
50
°C/W
W
Recommended Operating Conditions
Symbol
θJA
PD
Description
Thermal Resistance
Maximum Power Dissipation
2
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.
4
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2603.2008.06.1.0
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Electrical Characteristics1
VAIN = VINB1 = VINB2 = VINL12 = VINL34 = 3.6V, CBYP = 10nF, TA = -40°C to 85°C, unless noted otherwise. Typical values are
at TA = 25°C.
Symbol
Description
Power Supply
Input Voltage Range
VIN
IQ
Quiescent Current
ISHDN
Input Shutdown Current
UVLO
Under-Voltage Lockout
Conditions
Min
Typ
2.7
VENB1 = VENL3 = 3.6V, No Load , VFBB1 = VFBL3 = 3.6V
VENx = AGND
VIN rising
VIN falling
Hysteresis
Oscillator Frequency
FOSC
tS,BYP
Bypass Filter Startup Time
VENB1 = 3.6V
DC-DC1 (Buck1): 1.2A Step-Down Converter
VOUT_RANGE
Output Voltage Range
TA = 25°C, 20mA Load
Output Voltage Accuracy
VOUT_ACC
TA = -40°C to 85°C, 20mA Load
VOUT_TOL
Output Voltage Tolerance
0A to 1.2A Load; VIN = 2.7V to 5.5V
TA = 25°C, 20mA Load
VFBB1_ACC
Feedback Voltage Accuracy
TA = -40°C to 85°C, 20mA Load
ΔVOUT/ΔIOUT Load Regulation
0A to 1.2A Load
ΔVOUT/ΔVIN Line Regulation
VIN = 2.7V to 5.5V
ISHDN
Shutdown Current
VENB1 = GND
ILX_LEAK
LX Leakage Current
VINB1 = 5.5V, VLX1 = 0V to VINB1
ILIM
P-Channel Current Limit
RDS(ON)H
High Side Switch On-Resistance
Low Side Switch On-Resistance
RDS(ON)L
tS
Start-Up Time
Enable to Output Regulation
DC-DC2 (Buck2): 600mA Step-Down Converter
VOUT_RANGE
Output Voltage Range
TA = 25°C, 20mA Load
VOUT_ACC
Output Voltage Accuracy
TA = - 40°C to 85°C, 20mA Load
VOUT_TOL
Output Voltage Tolerance
0mA to 600mA Load; VIN = 2.7V to 5.5V
TA = 25°C, 20mA Load
Feedback Voltage Accuracy
SELB2 = '0
TA = -40°C to 85°C, 20mA Load
VFBB2_ACC
TA = 25°C, 20mA Load
Feedback Voltage Accuracy
SELB2 = '1'
TA = -40°C to 85°C, 20mA Load
ΔVOUT/ΔIOUT Load Regulation
0mA to 600mA Load
ΔVOUT/ΔVIN Line Regulation
VIN = 2.7V to 5.5V
ISHDN
Shutdown Current
VENB2 = GND
ILX_LEAK
LX Leakage Current
VINB2 = 5.5V, VLX2 = 0 to VINB2
ILIM
P-Channel Current Limit
High Side Switch On-Resistance
RDS(ON)H
RDS(ON)L
Low Side Switch On-Resistance
tS
Start-Up Time
Enable to Output Regulation
100
Max
Units
5.5
200
1.0
2.6
V
μA
μA
V
V
mV
MHz
μs
VINB1
+1.5
+2.5
+3.0
0.609
0.615
V
%
%
%
V
V
%
%/V
μA
μA
A
mΩ
mΩ
μs
1.8
250
1.5
200
0.6
-1.5
-2.5
-3.0
0.591
0.585
0.6
0.6
0.4
0.2
1.0
1.0
1.7
145
200
200
0.6
-1.5
-2.5
-3.0
0.591
0.585
0.763
0.756
0.6
0.6
0.775
0.775
0.2
0.2
VINB2
+1.5
+2.5
+3.0
0.609
0.615
0.787
0.794
1.0
1.0
1.3
230
180
200
V
%
%
%
V
V
%
%/V
μA
μA
A
mΩ
mΩ
μs
1. The AAT2603 is guaranteed to meet performance specification from -40°C to +85°C and is assured by design, characterization and correlation with statistical process controls.
2603.2008.06.1.0
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PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Electrical Characteristics1
VAIN = VINB1 = VINB2 = VINL12 = VINL34 = 3.6V, CBYP = 10nF, TA = -40°C to 85°C, unless noted otherwise. Typical values are
at TA = 25°C.
Symbol
Description
Conditions
400mA LDO Regulators (LDO1, LDO2)
VOUT_RANGE
Output Voltage Range
VFB_ACC
VFB_TOL
ΔVOUT/ΔIOUT
ΔVOUT/ΔVIN
IOUT(MAX)
ILIM
VDO
PSRR
tS
200mA LDO
VOUT_RANGE
VFB_ACC
TA = 25°C, 1mA Load
TA = -40°C to 85°C, 1mA Load
0mA to 400mA Load, VIN = 2.7V to 5.5V
1mA to 400mA Load
VIN = 3.3V to 5.5V, 100mA Load
Feedback Voltage Accuracy
Feedback Voltage Tolerance
Load Regulation
Line Regulation
Maximum Output Current
Output Current Limit
Dropout Voltage
Power Supply Rejection Ratio
Start-Up Time
Regulators (LDO3, LDO4)
Output Voltage Range
Min
Typ
1.5
1.2
1.2
1.2
Max
Units
VINL12
1.218
1.23
1.236
V
V
V
V
%
%/V
mA
mA
mV
dB
μs
0.3
0.08
400
1000
300
50
200
400mA Load
f < 10KHz, COUTL1,2 = 4.7μF, 10mA Load
VBYP already enabled; COUT = 4.7μF
Feedback Voltage Accuracy
Feedback Voltage Tolerance
VFB_TOL
ΔVOUT/ΔIOUT Load Regulation
ΔVOUT/ΔVIN
Line Regulation
IOUT(MAX)
Maximum Output Current
ILIM
Output Current Limit
VDO
Dropout Voltage
PSRR
Power Supply Rejection Ratio
eN
RMS Output Noise
tS
Start-Up Time
Logic Inputs/Outputs
VEN(H)
Input Logic High Voltage
VEN(L)
Input Logic Low Voltage
IEN
Logic Input Current
Thermal
TSD
Over-Temperature Shutdown Threshold
TSD(HYS)
Over-Temperature Shutdown Hysteresis
TA = 25°C, 1mA Load
TA = -40°C to +85°C, 1mA Load
0mA to 200mA Load, VIN = 2.7V to 5.5V
0mA to 200mA Load
VIN = 3.3V to 5.5V, 100mA Load
1.2
1.182
1.17
1.164
500
VINL34
1.218
1.23
1.236
0.2
0.02
200
1500
200
50
45
200
200mA Load
f < 10KHz, COUTL3,4 = 4.7μF, 10mA Load
Power BW: 100~100KHz
VBYP already enabled; COUT = 4.7μF
350
1.4
0.4
1.5
VEN = 1.4V2
140
15
V
V
V
V
%
%/V
mA
mA
mV
dB
μVrms
μs
V
V
μA
°C
°C
1. The AAT2603 is guaranteed to meet performance specification from -40°C to +85°C and is assured by design, characterization and correlation with statistical process controls.
2. The enable pins have internal 1.6MΩ pull-down resistors.
6
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2603.2008.06.1.0
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Typical Characteristics—DC-DC1 (Buck1)
Efficiency vs. Output Current
Load Regulation
(VOUTB1 = 3.3V; L = 3.3µH)
(VOUTB1 = 3.3V; L = 3.3µH)
0.4
Output Voltage Error (%)
100
90
Efficiency (%)
80
70
60
50
40
30
VIN = 5V
VIN = 4.2V
VIN = 3.6V
20
10
0
0.1
1
10
100
1000
VIN = 5V
VIN = 4.2V
VIN = 3.6V
0.2
0
-0.2
-0.4
0.1
10000
1
Output Current (mA)
Line Regulation
10000
(VOUTB1 = 3.3V; VIN = 4.2V)
0.4
IOUT = 1.2A
IOUT = 600mA
IOUT = 300mA
IOUT = 100mA
IOUT = 10mA
IOUT = 1mA
IOUT = 0.1mA
0.2
0
Output Voltage Error (%)
Output Voltage Error (%)
1000
Output Voltage Error vs. Temperature
0.4
-0.2
-0.4
3.6
4.4
4
4.8
IOUT = 1.2A
IOUT = 0.1mA
0.2
0
-0.2
-0.4
-40
5.2
-15
Input Voltage (V)
10
35
60
85
Temperature (°C)
P-Channel RDS(ON) vs. Input Voltage
Load Transient
(VOUTB1 = 3.3V)
(VOUTB1 = 3.3V; VIN = 4.2V; IOUTB1 = 100mA to 1200mA; CFF = 0pF)
250
Output Voltage
(AC Coupled) (top)
0.4
200
150
100
T = 120°C
T = 100°C
T = 85°C
T = 25°C
50
3.1
3.5
3.9
4.3
4.7
5.1
0
-0.2
1.5
-0.4
1
0.5
0
5.5
Input Voltage (V)
2603.2008.06.1.0
0.2
Output Current
(bottom)
P-Channel RDS(ON) (mΩ)
100
Output Current (mA)
(VOUTB1 = 3.3V; L = 3.3µH)
0
2.7
10
Time (100µs/div)
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PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Typical Characteristics—DC-DC1 (Buck1)
Load Transient
Load Transient
(VOUTB1 = 3.3V; VIN = 4.2V; IOUTB1 = 100mA to 1200mA; CFF = 100pF)
(VOUTB1 = 3.3V; VIN = 4.2V; IOUTB1 = 600mA to 1200mA; CFF = 0pF)
0.2
0.1
1.5
-0.2
1
0.5
0
Output Voltage
(AC Coupled) (top)
-0.1
0
-0.1
-0.2
1.5
1
0.5
0
Time (100µs/div)
Time (50µs/div)
Load Transient
Line Transient
(VOUTB1 = 3.3V; VIN = 4.2V; IOUTB1 = 600mA to 1200mA; CFF = 100pF)
(VOUTB1 = 3.3V; VIN = 4.2V to 5V; IOUTB1 = 700mA)
1
0.5
0
Input Voltage (top)
Output Voltage
(AC Coupled) (top)
1.5
Output Current
(bottom)
0
-0.1
4
0.1
0
-0.1
Output Voltage
(AC Coupled) (bottom)
5
0.1
-0.2
Output Current
(bottom)
0
Output Current
(bottom)
Output Voltage
(AC Coupled) (top)
0.1
-0.2
Time (100µs/div)
Time (50µs/div)
Soft-Start
(VOUTB1 = 3.3V; VIN = 4.2V; IOUTB1 = 1.2A)
4
2
0
4
3
2
1
Output Voltage
(bottom)
Enable Voltage (top)
6
0
Time (100µs/div)
8
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2603.2008.06.1.0
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Typical Characteristics—DC-DC2 (Buck2)
Efficiency vs. Output Current
Efficiency vs. Output Current
(VOUTB2 = 1.3V; L = 1.5µH)
(VOUTB2 = 1V; L = 1.2µH)
100
100
90
90
80
Efficiency (%)
Efficiency (%)
80
70
60
50
40
VIN = 5V
VIN = 4.2V
VIN = 3.6V
VIN = 2.7V
30
20
10
70
60
50
40
VIN = 5V
VIN = 4.2V
VIN = 3.6V
VIN = 2.7V
30
20
10
0
0
0.1
1
10
100
1000
0.1
1
10
Output Current (mA)
Load Regulation
Load Regulation
(VOUTB2 = 1.3V; L = 1.5µH)
(VOUTB2 = 1V; L = 1.2µH)
Output Voltage Error (%)
Output Voltage Error (%)
0.4
VIN = 5V
VIN = 4.2V
VIN = 3.6V
VIN = 2.7V
0.2
0
-0.2
-0.4
0.1
1
100
10
VIN = 5V
VIN = 4.2V
VIN = 3.6V
VIN = 2.7V
0.2
0
-0.2
-0.4
0.1
1000
1
10
Output Current (mA)
100
1000
10000
Output Current (mA)
Line Regulation
Line Regulation
(VOUTB2 = 1.3V; L = 1.5µH)
(VOUTB2 = 1V; L = 1.2µH)
0.6
0.6
IOUT = 600mA
IOUT = 300mA
IOUT = 100mA
IOUT = 10mA
IOUT = 1mA
IOUT = 0.1mA
0.4
0.2
0
Output Voltage Error (%)
Output Voltage Error (%)
1000
Output Current (mA)
0.4
-0.2
-0.4
-0.6
2.7
100
3.1
3.5
3.9
4.3
4.7
5.1
5.5
0.2
0
-0.2
-0.4
-0.6
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
Input Voltage (V)
Input Voltage (V)
2603.2008.06.1.0
IOUT = 600mA
IOUT = 300mA
IOUT = 100mA
IOUT = 10mA
IOUT = 1mA
IOUT = 0.1mA
0.4
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9
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Typical Characteristics—DC-DC2 (Buck2)
Output Voltage Error vs. Temperature
Switching Frequency vs. Input Voltage
(VOUTB2 = 1.3V; VIN = 3.6V)
(VOUTB2 = 1.3V; IOUTB2 = 600mA)
Switching Frequency (MHz)
Output Voltage Error (%)
0.6
IOUT = 600mA
IOUT = 0.1mA
0.4
0.2
0
-0.2
-0.4
-0.6
-40
-15
10
35
60
85
1.505
1.5
1.495
1.49
1.485
1.48
1.475
1.47
1.465
1.46
2.7
3.9
4.3
4.7
5.1
5.5
Load Transient
(VOUTB2 = 1.3V)
(VOUTB2 = 1.3V; VIN = 3.6V; IOUTB2 = 100mA to 600mA; CFF = 0pF)
0.05
Output Voltage
(AC Coupled) (top)
0.1
350
300
250
200
150
T = 120°C
T = 100°C
T = 85°C
T = 25°C
100
50
3.1
3.5
3.9
4.3
4.7
5.1
0
-0.05
-0.1
1
0.5
Output Current
(bottom)
P-Channel RDS(ON) (mΩ)
3.5
P-Channel RDS(ON) vs. Input Voltage
400
0
2.7
3.1
Input Voltage (V)
Temperature (°C)
0
5.5
Input Voltage (V)
Time (50µs/div)
Load Transient
Load Transient
(VOUTB2 = 1.3V; VIN = 3.6V; IOUTB2 = 100mA to 600mA; CFF = 100pF)
(VOUTB2 = 1.3V; VIN = 3.6V; IOUTB2 = 300mA to 600mA; CFF = 0pF)
-0.1
1
0.5
0
0
-0.05
Time (50µs/div)
10
1
0.5
Output Current
(bottom)
-0.05
Output Voltage
(AC Coupled) (top)
0.05
0
Output Current
(bottom)
Output Voltage
(AC Coupled) (top)
0.1
0.05
0
Time (20µs/div)
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2603.2008.06.1.0
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Typical Characteristics—DC-DC2 (Buck2)
Load Transient
Line Transient
(VOUTB2 = 1.3V; VIN = 3.6V; IOUTB2 = 300mA to 600mA; CFF = 100pF)
(VOUTB2 = 1.3V; VIN = 3.6 to 4.2V; IOUTB2 = 300mA)
1
0.5
0
Input Voltage (top)
Output Voltage
(AC Coupled) (top)
-0.05
Output Current
(bottom)
0
0.3
5
0.25
4
0.2
3
0.15
2
0.1
1
0.05
0
0
-1
-0.05
-2
-0.1
Output Voltage
(AC Coupled) (bottom)
0.05
6
Time (50µs/div)
Time (20µs/div)
Soft-Start
4
2
0
1.5
1
0.5
Output Voltage
(bottom)
Enable Voltage (top)
(VOUTB2 = 1.3V; VIN = 3.6V; IOUTB2 = 600mA)
0
Time (100µs/div)
2603.2008.06.1.0
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11
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Typical Characteristics—LDO1/LDO2
Load Regulation
Load Regulation
(VOUTL1&2 = 3V; VIN = 3.6V)
(VOUTL1&2 = 1.5V; VIN = 3.6V)
0.4
Output Voltage Error (%)
Output Voltage Error (%)
0.4
0.2
0
-0.2
-0.4
0.1
1
10
100
0.2
0
-0.2
-0.4
0.1
1000
1
Output Current (mA)
Line Regulation
Output Voltage Error (%)
0.4
IOUT = 400mA
IOUT = 100mA
IOUT = 10mA
IOUT = 1mA
IOUT = 0.1mA
0.2
0
-0.2
-0.4
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
0.2
0
-0.2
IOUT = 400mA
IOUT = 0.1mA
-0.4
-40
-15
Input Voltage (V)
10
35
60
85
Temperature (°C)
Load Transient
Load Transient
(VOUTL1&2 = 2.8V; VIN = 3.6V; IOUTL1&2 = 1mA to 50mA)
(VOUTL1&2 = 2.8V; VIN = 3.6V; IOUTL1&2 = 1mA to 200mA)
0.1
0.02
0.05
0.05
0
0
-0.05
-0.1
0.4
0.2
Output Current
(bottom)
-0.04
Output Current
(bottom)
0
-0.02
Output Voltage
(AC Coupled) (top)
0.04
0
-0.05
-0.2
Time (100µs/div)
12
1000
(VOUTL1&2 = 2.8V; VIN = 3.6V)
0.4
Output Voltage Error (%)
100
Output Voltage Error vs. Temperature
(VOUTL1&2 = 1.5)
Output Voltage
(AC Coupled) (top)
10
Output Current (mA)
Time (100µs/div)
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2603.2008.06.1.0
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Load Transient
Line Transient
(VOUTL1&2 = 2.8V; VIN = 3.6V; IOUTL1&2 = 1mA to 400mA)
(VOUTL1&2 = 2.8V; VIN = 3.6 to 4.2V; IOUTL1&2 = 400mA)
5
0.1
4
-0.1
-0.2
0.5
0
3
0.2
0.1
0
Output Voltage
(bottom)
0
Input Voltage (top)
0.2
Output Current
(bottom)
Output Voltage
(AC Coupled) (top)
Typical Characteristics—LDO1/LDO2
-0.1
-0.2
Time (20µs/div)
Time (200µs/div)
Soft-Start
4
2
0
3
2
1
Output Voltage
(bottom)
Enable Voltage (top)
(VOUTL1&2 = 2.8V; VIN = 3.6V; IOUTL1&2 = 400mA)
0
Time (500µs/div)
2603.2008.06.1.0
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13
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Typical Characteristics—LDO3/LDO4
Load Regulation
Load Regulation
(VOUTL3&4 = 3V; VIN = 3.6V)
(VOUTL3&4 = 1.2V; VIN = 3.6V)
0.4
Output Voltage Error (%)
Output Voltage Error (%)
0.4
0.2
0
-0.2
0.2
0
-0.2
-0.4
-0.4
0
1
100
10
0.1
1000
1
Output Current (mA)
Output Voltage Error vs. Temperature
(VOUTL3&4 = 1.2V)
(VOUTL3&4 = 2.8V; VIN = 3.6V)
0.4
0.4
IOUT = 400mA
IOUT = 100mA
IOUT = 10mA
IOUT = 1mA
IOUT = 0.1mA
0.2
Output Voltage Error (%)
Output Voltage Error (%)
1000
Output Current (mA)
Line Regulation
0
-0.2
-0.4
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
0.2
0
-0.2
IOUT = 200mA
IOUT = 0.1mA
-0.4
-40
Input Voltage (V)
-15
10
35
60
85
Temperature (°C)
Load Transient
Load Transient
(VOUTL3&4 = 2.8V; VIN = 3.6V; IOUTL3&4 = 1mA to 50mA)
(VOUTL3&4 = 2.8V; VIN = 3.6V; IOUTL3&4 = 1mA to 100mA)
0.02
0.05
Output Voltage
AC Coupled) (top)
-0.02
0
-0.02
-0.04
0.1
Output Current
(bottom)
0
-0.01
Output Current
(bottom)
Output Voltage
(AC Coupled) (top)
0.01
0
0
Time (100µs/div)
14
100
10
Time (100µs/div)
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2603.2008.06.1.0
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Typical Characteristics—LDO3/LDO4
Load Transient
Line Transient
(VOUTL3&4 = 2.8V; VIN = 3.6V; IOUTL3&4 = 1mA to 200mA)
(VOUTL3&4 = 2.8V; VIN = 3.6 to 4.2V; IOUTL3&4 = 200mA)
5
0.2
0
Input Voltage
(AC Coupled) (top)
-0.05
4
3
0.15
0.1
0.05
0
Output Voltage
(bottom)
0
Output Current
(bottom)
Output Voltage
(AC Coupled) (top)
0.05
-0.05
-0.1
Time (100µs/div)
Time (20µs/div)
Soft-Start
(VOUTL3&4 = 2.8V; VIN = 3.6V; IOUTL3&4 = 200mA)
4
2
0
3
2
1
Output Voltage
(bottom)
Enable Voltage (top)
6
0
Time (500µs/div)
2603.2008.06.1.0
www.analogictech.com
15
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Functional Block Diagram
AIN
INB 2
INB 1
LX1
ENB1
DC-DC1
(Buck1)
ENB2
FBB 1
PGND 1
ENL 1
ENL 2
LX2
Interface
and
Support
DC-DC2
(Buck2)
ENL 3
FBB 2
PGND 2
ENL 4
OUTL 1
SELB 2
LDO1
FBL 1
BYP
OUTL 2
LDO2
FBL 2
INL12
OUTL 3
LDO3
FBL 3
OUTL 4
INL34
LDO4
FBL 4
AGND
Functional Description
The AAT2603 is a highly integrated voltage regulating
power management unit for mobile handsets or other
portable devices. It includes two switch-mode step-down
converters (600mA [DC-DC2] and 1.2A [DC-DC1]), and
four low-dropout (LDO) regulators (two: 200mA, two:
400mA). It operates from an input voltage between 2.7V
and 5.5V making it ideal for lithium-ion or 5V regulated
power sources. All six converters have separate enable
pins for ease of use.
Step-Down Converters
The AAT2603 switch-mode, step-down converters are
constant frequency peak current mode PWM converters
with internal compensation. The input voltage range is
16
2.7V to 5.5V. The output voltage range is 0.6V to VIN.
The high 1.5MHz switching frequency allows the use of
small external inductor and capacitor.
The step-down converters offer soft-start to limit the
current surge seen at the input and eliminate output
voltage overshoot. The current across the internal
P-channel power switch is sensed and turns off when the
current exceeds the current limit. Also, thermal protection completely disables switching if internal dissipation
becomes excessive, thus protecting the device from
damage. The junction over-temperature threshold is
140°C with 15°C of hysteresis.
DC-DC1 (Buck1) is designed for a peak continuous output current of 1.2A. The high-side power switch has
been designed with a low RDSON of 145mΩ to allow for a
minimum dropout voltage of 174mV at full load current.
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2603.2008.06.1.0
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
It was designed to maintain over 90% efficiency at its
maximum rated output current load of 1.2A with a 3.3V
output. Peak efficiency is above 95%. Buck1 has excellent transient response, load and line regulation. Transient
response time is typically less than 20μs. The peak input
current is limited to 1.7A.
DC-DC2 (Buck2) is a 600mA step-down regulator designed
to dynamically shift between two output voltages by toggling the SELB2 pin. The internal reference voltage of the
buck regulator is changed based on the position of the
SELB2 pin.
Buck2 is designed to maintain over 85% efficiency at its
maximum rated output current of 600mA with a 1.2V
output. Peak efficiency is above 90%. Buck2 has excellent transient response, load and line regulation. The
peak inductor current is limited to 1.3A.
The two step-down converters on the AAT2603 have
highly flexible output voltage programming capability.
The output voltages can be factory programmed to preset output voltages or set by external resistors. The
“Part Number Descriptions” table lists the available voltage options for step-down converters Buck1 and Buck2.
Option 1 has externally adjustable output voltages for
both step-down converters. The dynamic voltage scaling
for Buck2 is still useable with external feedback resistors. When SELB2 is in the low position the feedback
voltage is compared to a 600mV reference, while when
SELB2 is high the reference voltage is 775mV. For most
other options, the output voltages of Buck2 are factory
programmed.
LDO Regulators
Application Information
DC-DC1/DC-DC2
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.
Table 1 displays suggested inductor values for various
output voltages.
Manufacturer’s specifications list both the inductor DC
current rating, which is a thermal limitation, and the
peak current rating, which is determined by the saturation characteristics. The inductor should not show any
appreciable saturation under normal load conditions.
Some inductors may meet the peak and average current
ratings yet result in excessive losses due to a high DCR.
Always consider the losses associated with the DCR and
its effect on the total converter efficiency when selecting
an inductor.
It is recommended that the inductor current rating
exceed the current limit of the step-down converter. See
Table 2 for example inductor values/vendors.
Input Capacitor
Select a 4.7μF to 10μF X7R or X5R ceramic capacitor for
the input; see Table 3 for suggested capacitor components. To estimate the required input capacitor size,
determine the acceptable input ripple level (VPP) and solve
for CIN (CINB1/CINB2). The calculated value varies with input
voltage and is a maximum when VIN is double the output
voltage.
The AAT2603 includes four LDO regulators. The regulators operate from the 2.7V to 5.5V input voltage to a
regulated output voltage. The LDO regulators have
adjustable output voltages set by resistors. Each LDO
consumes 50uA of quiescent current.
The two 200mA LDO regulators are stable with a small
4.7μF ceramic output capacitor. The low 200mV dropout
voltage at 200mA load allows a regulated output voltage
approaching the input voltage. Low output noise voltage
and high power supply rejection make these regulators
ideal for powering noise sensitive circuitry.
The two 400mA LDO regulators are stable with a small
4.7μF ceramic output capacitor. The low 300mV dropout
voltage at 400mA load allows a regulated output voltage
approaching the input voltage. These LDOs offer high
power supply rejection.
2603.2008.06.1.0
CIN =
V
VO
· 1- O
VIN
VIN
VPP
- ESR · FS
IO
VO
V
1
· 1 - O = for VIN = 2 · VO
VIN
VIN
4
CIN(MIN) =
1
VPP
- ESR · 4 · FS
IO
Always examine the ceramic capacitor DC voltage coefficient characteristics when selecting the proper value.
For example, the capacitance of a 10μF, 6.3V, X5R ceramic capacitor with 5.0V DC applied is actually about 6μF.
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17
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Part Number/
Type
Manufacturer
TDK
Inductance
(μH)
Rated Current
(A)
DCR (mΩ)
(max)
1.2
1.8
2.2
3.3
1
1.8
2.7
3.3
1.2
1.8
2.2
2.7
3.3
1
1.5
2.2
3.3
4.3
3.6
3.2
2.5
2.6
2.35
2.03
1.8
2.8
2.45
2.35
1.95
1.8
4
3.7
3.2
2.9
25
32
40
60
30
50
60
65
20
25
28
30
35
19 (typ)
22 (typ)
29 (typ)
36 (typ)
LTF5022
WE-TPC Type M
Wurth Electronik
WE-TPC Type MH
Murata
LQH55D
Size (mm)
LxWxH
5x5.2x2.2
4.8x4.8x1.8
4.8x4.8x2.8
5x5.7x4.7
Table 1: Suggested Inductor Components.
Configuration
Output Voltage
Inductor Value
Adjustable and
Fixed Output
Voltage
1V, 1.2V, 1.3V
1.5V, 1.8V
2.5V
2.8V, 3.3V
1.0μH to 1.2μH
1.5μH to 1.8μH
2.2μH to 2.7μH
3.3μH
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.
VO
V
· 1- O =
VIN
VIN
Table 2: Inductor Values for
Specific Output Voltages.
D · (1 - D) =
0.52 =
1
2
for VIN = 2 · VO.
The maximum input capacitor RMS current is:
IRMS = IO ·
Manufacturer
AVX
TDK
Murata
Taiyo Yuden
VO
V
· 1- O
VIN
VIN
Part Number
Value
Voltage
0603ZD105K
0603ZD225K
C1608X5R1E105K
C1608X5R1C225K
C1608X5R1A475K
C2012X5R1A106K
C3216X5R1A226K
GRM188R61C105K
GRM188R61A225K
GRM219R61A106K
GRM31CR71A226K
LMK107BJ475KA
1μF
2.2μF
1μF
2.2μF
4.7μF
10μF
22μF
1μF
2.2μF
10μF
22μF
4.7μF
10
10
25
16
10
10
10
16
10
10
10
10
Temp. Co.
Case
X5R
0603
0603
X5R
0805
1206
X5R
X7R
X5R
0603
0805
1206
0603
Table 3: Suggested Capacitor Components.
18
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2603.2008.06.1.0
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
IRMS(MAX) =
VO
· 1-
IO
2
VO
V
The term V
appears in both the input voltage ripple
and input capacitor RMS current equations and is a maximum when VO is twice VIN. This is why the input voltage
ripple and the input capacitor RMS current ripple are a
maximum at 50% duty cycle.
IN
IN
The input capacitor provides a low impedance loop for
the edges of pulsed current drawn by the AAT2603 stepdown switching regulators. Low ESR/ESL X7R and X5R
ceramic capacitors are ideal for this function. To minimize stray inductance, the capacitor should be placed as
closely as possible to the IC. This keeps the high frequency content of the input current localized, minimizing
EMI and input voltage ripple.
A laboratory test set-up typically consists of two long
wires running from the bench power supply to the evaluation board input voltage pins. The inductance of these
wires, along with the low-ESR ceramic input capacitor,
can create a high Q network that may affect converter
performance. This problem often becomes apparent in
the form of excessive ringing in the output voltage during load transients. Errors in the loop phase and gain
measurements can also result.
Since the inductance of a short PCB trace feeding the
input voltage is significantly lower than the power leads
from the bench power supply, most applications do not
exhibit this problem.
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 10μF to 22μF X5R
or X7R ceramic capacitor typically provides sufficient bulk
capacitance to stabilize the output during large load transitions and has the ESR and ESL characteristics necessary for low output ripple. A 10μF X5R or X7R ceramic
capacitor is required for DC-DC2 and a 22μF X5R or X7R
ceramic capacitor is required for DC-DC1; see Table 3 for
suggested capacitor components.
2603.2008.06.1.0
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 several 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 several switching cycles to the output capacitance can be estimated by:
COUT =
3 · ΔILOAD
VDROOP · FS
Once the average inductor current increases to the DC
load level, the output voltage recovers. The above equation establishes a limit on the minimum value for the
output capacitor with respect to load transients.
The internal voltage loop compensation also limits the
minimum output capacitor value to 10μF for DC-DC2 and
22μF for DC-DC1. 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
VOUT · (VIN(MAX) - VOUT)
L · FS · VIN(MAX)
2· 3
·
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.
Feedback Resistor Selection
Resistors R1 and R2 of Figure 1 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 59kΩ. Although a larger value
will further reduce quiescent current, it will also increase
the impedance of the feedback node, making it more
sensitive to external noise and interference. Table 42
summarizes the resistor values for various output voltages with R2 set to either 59kΩ for good noise immunity or 221kΩ for reduced no load input current.
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19
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
1.5V
VOUT
R1 = V
-1 · R2 = 0.6V - 1 · 59kΩ = 88.5kΩ
REF
The AAT2603 step-down regulators, combined with an
external feedforward capacitor (CFF in Figure 1), deliver
enhanced transient response for extreme pulsed load
applications.
Output Capacitor
VDC-DC1/VDC-DC2
CFF
For proper load voltage regulation and operational stability, a capacitor is required between pins VOUTLX and
AGND. The COUTLX capacitor connection to the LDO regulator ground pin should be made as direct as practically
possible for maximum device performance.
R1
VFBB1/VFBB2
R2
Figure 1: AAT2603 DC-DC1/DC-DC2 External
Resistor Output Voltage Programming.
VOUT (V)
R2 = 59kΩ
R1 (kΩ)
R2 = 221kW
R1 (kΩ)
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.8
1.85
2.0
2.5
3.3
29.4
39.2
49.9
59.0
68.1
78.7
88.7
118
124
137
187
267
113K
150K
187K
221K
261K
301K
332K
442K
464K
523K
715K
1.00M
Table 4: Feedback Resistors
for DC-DC1 and DC-DC2.
LDO1/LDO2/LDO3/LDO4
Input Capacitor
Typically, a 2.2μF or larger capacitor is recommended for
CINL12/CINL34/CAIN in most applications. The input capacitor
should be located as close to the input (INL12/INL34/
AIN) of the device as practically possible. CINL12/CINL34/
CAIN values greater than 2.2μF will offer superior input
line transient response and will assist in maximizing the
highest possible power supply ripple rejection.
20
Ceramic, tantalum, or aluminum electrolytic capacitors
may be selected for CINL12/CINL34/CAIN. There is no specific
capacitor ESR requirement for CINL12/CINL34/CAIN. However,
for 200mA/400mA LDO regulators output operation,
ceramic capacitors are recommended for CINL12/CINL34/CAIN
due to their inherent capability over tantalum capacitors
to withstand input current surges from low impedance
sources such as batteries in portable devices.
The AAT2603 LDO regulators have been specifically
designed to function with very low ESR ceramic capacitors. Although the device is intended to operate with
these low ESR capacitors, it is stable over a very wide
range of capacitor ESR, thus it will also work with higher
ESR tantalum or aluminum electrolytic capacitors.
However, for best performance, ceramic capacitors are
recommended.
Typical output capacitor values for maximum output current conditions range from 4.7μF to 10μF. If desired,
COUTLX may be increased without limit.
Bypass Capacitor and Low Noise Applications
A bypass capacitor pin is provided to enhance the very
low noise characteristics of the AAT2603 LDO3 and LDO4
regulators. The bypass capacitor is not necessary for
operation of the AAT2603. However, for best device performance, a small ceramic capacitor should be placed
between the bypass pin (BYP) and the device analog
ground pin (AGND). The value of CBYP should be 10nF. For
lowest noise and best possible power supply ripple rejection performance a 10nF capacitor should be used. To
practically realize the highest power supply ripple rejection and lowest output noise performance, it is critical
that the capacitor connection between the BYP pin and
AGND pin be direct and PCB traces should be as short as
possible. Refer to the PCB Layout Recommendations section of this datasheet for examples.
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AAT2603
Total Power Solution for Portable Applications
There is a relationship between the bypass capacitor
value and the LDO regulator turn-on time. In applications where fast device turn-on time is desired, the
value of CBYP should be reduced.
In applications where low noise performance and/or
ripple rejection are less of a concern, the bypass capacitor may be omitted. The fastest device turn-on time will
be realized when no bypass capacitor is used.
DC leakage on this pin can affect the LDO regulator output
noise and voltage regulation performance. For this reason, the use of a low leakage, high quality ceramic (NPO
or C0G type) or film capacitor is highly recommended.
Feedback Resistor Selection
Resistors R1 and R2 of Figure 2 program the output to
regulate at a voltage higher than 1.5V for LDO1/LDO2
and 1.2V for LDO3/LDO4. To limit the bias current
required for the external feedback resistor string while
maintaining good noise immunity, the minimum suggested value for R2 is 100kΩ. 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. Tables 5
and 6 summarize the resistor values for various output
voltages with R2 set to 100kΩ.
1.5V
VOUT
R1 = V
-1 · R2 = 1.2V - 1 · 100kΩ = 24.9kΩ
REF
VOUT (V)
R2 = 100kΩ
R1 (kΩ)
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3
3.1
3.2
3.3
8.25
16.5
24.9
33.2
41.2
49.9
59
66.5
75
82.5
90.9
100
107
118
124
133
140
150
158
165
174
Table 5: Feedback Resistor Values
for LDO3 and LDO4.
VOUT (V)
R2 = 100kΩ
R1 (kΩ)
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3
3.1
3.2
3.3
24.9
33.2
41.2
49.9
59
66.5
75
82.5
90.9
100
107
118
124
133
140
150
158
165
174
VOUTLX
R1
VFBLX
R2
Figure 2: AAT2603 LDO1/LDO2/LDO3/LDO4
External Resistor Output Voltage Programming.
Table 6: Feedback Resistor Values
for LDO1 and LDO2.
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21
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Thermal Calculations
There are three types of losses associated with the
AAT2603 total power management solution [two stepdown and four LDO regulators]: switching losses, conduction losses, and quiescent current losses. Conduction
losses are associated with the RDS(ON) characteristics of
the internal power switches/FETs of both of the stepdown regulators and the power loss associated with the
voltage difference across the pass switch/FET of the four
LDO regulators. 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 the following
(quiescent and switching losses are ignored, since conduction losses are so dominant):
PDC-DC1 =
PDC-DC2 =
IO12 · (RDS(ON)H1 · VOB1 + RDS(ON)L1 · [VINB1 - VOB1])
VINB1
Since RDS(ON) and conduction losses all vary with input
voltage, the dominant losses should be investigated over
the complete input voltage range. Given the total conduction losses, the maximum junction temperature
(125°C) can be derived from the θJA for the TQFN44-28
package which is 50°C/W.
TJ(MAX) = PTOTAL · θJA + TA
TJ(MAX):
PTOTAL:
ΘJA:
TA:
Layout
The suggested PCB layout for the AAT2603 is shown in
Figures 4 and 5. The following guidelines should be used
to help ensure a proper layout.
1.
IO22 · (RDS(ON)H2 · VOB2 + RDS(ON)L2 · [VINB2 - VOB2])
VINB2
2.
PLDO1 = ILDO1 · (VINL12 - VOL1)
PLDO2 = ILDO2 · (VINL12 - VOL2)
3.
PLDO3 = ILDO3 · (VINL34 - VOL3)
PLDO4 = ILDO4 · (VINL34 - VOL4)
PTOTAL = PDC_DC1 + PDC_DC2 + PLDO1 + PLDO2 + PLDO3 + PLDO4
PDC-DCX: Power dissipation of the specific DC-DC
regulator
IOX:
Output current of the specific DC-DC regulator
RDS(ON)HX: Resistance of the internal high-side switch/FET
RDS(ON)LX: Resistance of the internal low-side switch/FET
VOBX:
Output voltage of the specific DC-DC regulator
VINBX:
Input voltage of the specific DC-DC regulator
PLDOX:
Power dissipation of the specific LDO regulator
ILDOX:
Output current of the specific LDO regulator
VINLXX: Input voltage of the specific LDO regulator
VOLX:
Output voltage of the specific LDO regulator
PTOTAL: Total power dissipation of the AAT2603
22
Maximum junction temperature
Total conduction losses
Thermal impedance of the package
Ambient temperature
4.
5.
The input capacitors (C1, C2, C7, C13, and C16)
should connect as closely as possible to INB1 (Pin
26), INB2 (Pin 27), AIN (Pin 20), INL12 (Pin 16),
INL34 (Pin 8), and AGND/PGND1/PGND2 (Pins 5,
25, and 27).
C3/C18 (step-down regulator output capacitors) and
L1/L2 should be connected as closely as possible.
The connection of L1/L2 to the LX1/LX2 pins should
be as short as possible.
The feedback trace or FBXX pin (Pins 3, 6, 10, 14,
18, and 21) 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 FBXX pin (Pins 3, 6, 10, 14, 18,
and 21) to minimize the length of the high impedance feedback trace.
The resistance of the trace from the load return to
the PGND1/PGND2 (Pins 25 and 28) 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 TDFN44-28 exposed paddle to
the ground plane.
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AAT2603
Total Power Solution for Portable Applications
VIN
C2
J1
3-Prong Header
1
ENL1
2
VIN
C18
OUTB1
L1
ENB1
2
SELB2
GND
3
3
C1
J2
3-Prong Header
1
C17
R1
ENB1
GND
INL12
16
OUTL1
15
AGND
6
FBL3
7
OUTL3
FBL1
ENL1
BYP
ENL4
VIN
C16
R4
ENL2
C15
R3
C14
OUTL2 C13
VIN
GND
OUTL1
14
13
12
11
3
9
3
R2
ENB1
OUTL2
17
OUTL3
GND
22
18
C5
ENL4
SELB2
FBL2
ENL3
5
10
2
23
19
8
ENL3
2
LX1
ENL2
FBL4
R10
AIN
FBB2
INL34
J6
3-Prong Header
1
ENB2
20
OUTL4
J5
3-Prong Header
1
21
3
R12
R9
FBB1
LX2
2
4
ENL3
3
24
ENB2
C4
PGND1
R11
25
1
INB1
3
ENB2
2
L2
INB2
ENL2
2
1
PGND2
1
J4
3-Prong Header
26
28
J3
3-Prong Header
27
C3
OUTB2
U1
AAT2603
VIN
R5
C11
C12
C6
C7
ENL1
C8
ENL4
C10
R6
OUTL4
R7
J7
3-Prong Header
1
2
R8
C9
SELB2
3
Figure 3: AAT2603 Evaluation Board Schematic.
2603.2008.06.1.0
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23
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Figure 4: AAT2603 Evaluation Board Top Side PCB Layout.
Figure 5: AAT2603 Evaluation Board Bottom Side PCB Layout.
24
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2603.2008.06.1.0
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Ordering Information
Output Voltage1
DC-DC1
(Buck1)
DC-DC2 (Buck2)
(SELB2 = Low)
DC-DC2 (Buck2)
(SELB2 = High)
Ext. Adj.
(VREF = 600mV)
3.3V
Ext. Adj.
(VREF = 600mV)
Ext. Adj.
(VVREF = 600mV)
1.0V
Ext. Adj.
(VVREF= 775mV)
1.3V
1.0V
1.3V
Package
TQFN44-28
TQFN44-28
TQFN44-28
Marking2
Part Number (Tape and Reel)3
3AXYY
AAT2603INJ-1-T1
AAT2603INJ-2-T1
AAT2603INJ-3-T1
All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means semiconductor
products that are in compliance with current RoHS standards, including the requirement that lead not exceed
0.1% by weight in homogeneous materials. For more information, please visit our website at
http://www.analogictech.com/about/quality.aspx.
1. Buck 1 and Buck 2 output voltages can be factory programmed to most common output voltages. Contact your local sales representative for availability and minimum order
quantities.
2. XYY = assembly and date code.
3. Sample stock is generally held on part numbers listed in BOLD.
2603.2008.06.1.0
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25
PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Package Information
TQFN44-28
Pin 1 Dot
by Marking
C0.3
2.600 ± 0.050
4.000 ± 0.050
Detail "A"
4.000 ± 0.050
2.600 ± 0.050
Top View
Bottom View
0.400 ± 0.050
0.430 ± 0.050
0.750 ± 0.050
0.230 ± 0.050
0.203 REF
0.050 ± 0.050
Side View
Pin 1 Indicator
Detail "A"
1. The leadless package family, which includes QFN, TQFN, DFN, TDFN and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing
process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection.
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Phone (408) 737-4600
Fax (408) 737-4611
© Advanced Analogic Technologies, Inc.
AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights, or other intellectual
property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice. Except as provided in AnalogicTech’s terms and
conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied warranty relating to the sale and/or use of AnalogicTech products including liability or warranties
relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. In order to minimize risks associated with the customer’s applications, adequate
design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to
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brand and product names appearing in this document are registered trademarks or trademarks of their respective holders.
26
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