FEATURES
n
LTC3576/LTC3576-1
Switching Power Manager
with USB On-the-Go + Triple
Step-Down DC/DCs
DESCRIPTION
The LTC
®
3576/LTC3576-1 are highly integrated power
management and battery charger ICs for Li-Ion/Polymer
battery applications. They each include a high efficiency,
bidirectional switching PowerPath™ manager with auto-
matic load prioritization, a battery charger, an ideal diode, a
controller for an external high voltage switching regulator
and three general purpose step-down switching regulators
with I
2
C adjustable output voltages. The internal switch-
ing regulators automatically limit input current for USB
compatibility and can also generate 5V at 500mA for USB
on-the-go applications when powered from the battery.
Both the USB and external switching regulator power paths
feature Bat-Track optimized charging to provide maximum
power to the application from supplies as high as 38V. An
overvoltage circuit protects the LTC3576/LTC3576-1 from
damage due to high voltage on the V
BUS
or WALL pins with
just two external components. The LTC3576/LTC3576-1 are
available in a low profile 38-pin (4mm
×
6mm
×
0.75mm)
QFN package.
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. Bat-Track and PowerPath are trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners. Protected by U.S.
Patents, including 6522118, 6404251.
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Bidirectional Switching Regulator with Bat-Track™
Adaptive Output Control Provides Efficient Charging
and a 5V Output for USB On-The-Go
Bat-Track Control of External High Voltage Step-
Down Switching Regulator
Overvoltage Protection Guards Against Damage
Instant-On Operation with Discharged Battery
Triple Step-Down Switching Regulators with I
2
C
Adjustable Outputs (1A/400mA/400mA I
OUT
)
180mΩ Internal Ideal Diode + External Ideal Diode
Controller Powers the Load in Battery Mode
Li-Ion/Polymer Battery Charger (1.5A Max I
CHG
)
Battery Float Voltage: 4.2V (LTC3576), 4.1V (LTC3576-1)
Compact (4mm
×
6mm
×
0.75mm) 38-Pin QFN Package
APPLICATIONS
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HDD-Based Media Players
GPS, PDAs, Digital Cameras, Smart Phones
Automotive Compatible Portable Electronics
TYPICAL APPLICATION
High Efficiency PowerPath Manager with Overvoltage Protection
and Triple Step-Down Regulator
AUTOMOTIVE
FIREWIRE, ETC.
USB OR
5V AC
ADAPTER
LT3653
PowerPath Switching Regulator Efficiency
to System Load (P
VOUT
/P
VBUS
)
100
90
TO OTHER
LOADS
EFFICIENCY (%)
OVERVOLTAGE
PROTECTION
EXTERNAL HIGH VOLTAGE
BUCK CONTROLLER
USB COMPLIANT
BIDIRECTIONAL
SWITCHING
REGULATOR
CC/CV
BATTERY
CHARGER
CHARGE
LTC3576/LTC3576-1
T
ALWAYS ON LDO
TRIPLE
HIGH EFFICIENCY
STEP-DOWN
SWITCHING
REGULATORS
I
2
C PORT
1
2
3
0V
OPTIONAL
80
70
60
50
40
30
BAT = 4.2V
BAT = 3.3V
+
Li-Ion
3.3V/20mA
0.8V TO 3.6V/400mA
0.8V TO 3.6V/400mA
0.8V TO 3.6V/1A
RST
2
RTC/LOW
POWER LOGIC
MEMORY
I/O
CORE
μPROCESSOR
I
2
C
3576 TA01
20
10
0
10
V
BUS
= 5V
I
BAT
= 0mA
10x MODE
100
LOAD CURRENT (mA)
1000
3576 TA01b
ENABLE
CONTROLS
6
3576fb
1
LTC3576/LTC3576-1
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2, 3)
PIN CONFIGURATION
TOP VIEW
I
LIM1
I
LIM0
V
BUS
V
BUS
V
OUT
BAT
31 IDGATE
30
CHRG
29 PROG
28
ACPR
27 WALL
39
26 V
C
25 FB2
24 V
IN2
23 SW2
22 EN2
21
RST3
20 FB3
13 14 15 16 17 18 19
V
IN3
SW3
SCL
SDA
EN3
NC
NC
SW
V
BUS
, WALL (Transient) t < 1ms,
Duty Cycle < 1% .......................................... –0.3V to 7V
V
BUS
, WALL (Static), BAT, V
IN1
, V
IN2
, V
IN3
,
V
OUT
, ENOTG, NTC, SDA, SCL, DV
CC
,
RST3, CHRG
................................................ –0.3V to 6V
I
LIM0
, I
ILIM1
........ –0.3V to Max(V
BUS
, V
OUT
, BAT) + 0.3V
EN1, EN2, EN3 .............................. –0.3V to V
OUT
+ 0.3V
FBx (x = 1, 2, 3) ..............................–0.3V to V
INx
+ 0.3V
I
OVSENS
...................................................................10mA
I
CLPROG
....................................................................3mA
I
CHRG
, I
RST3
............................................................50mA
I
PROG
........................................................................2mA
I
LDO3V3
...................................................................30mA
I
SW1
, I
SW2
(Continuous) .......................................600mA
I
SW
, I
SW3
, I
BAT
, I
VOUT
(Continuous) ..............................2A
Maximum Junction Temperature........................... 125°C
Operating Temperature Range..................–40°C to 85°C
Storage Temperature Range...................–65°C to 125°C
38 37 36 35 34 33 32
CLPROG 1
LDO3V3 2
NTCBIAS 3
NTC 4
OVGATE 5
OVSENS 6
FB1 7
V
IN1
8
SW1 9
EN1 10
ENOTG 11
DV
CC
12
UFE PACKAGE
38-LEAD (4mm 6mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 34°C/W
EXPOSED PAD (PIN 39) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LTC3576EUFE#PBF
LTC3576EUFE-1#PBF
TAPE AND REEL
LTC3576EUFE#TRPBF
LTC3576EUFE-1#TRPBF
PART MARKING
3576
35761
PACKAGE DESCRIPTION
38-Lead (4mm
×
6mm) Plastic QFN
38-Lead (4mm
×
6mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 85°C
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS
SYMBOL
V
BUS
I
VBUS(LIM)
PARAMETER
Input Supply Voltage
Total Input Current
PowerPath Switching Regulator—Step-Down Mode
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
BUS
= 5V, BAT = 3.8V, DV
CC
= 3.3V, R
CLPROG
= 3.01k, unless
otherwise noted.
CONDITIONS
MIN
4.35
1× Mode
5× Mode
10× Mode
Low Power Suspend Mode
High Power Suspend Mode
1× Mode
5×, 10× Modes
Low/High Power Suspend Modes
l
l
l
l
l
TYP
MAX
5.5
UNITS
V
mA
mA
mA
mA
mA
mA
mA
mA
3576fb
82
440
800
0.32
1.6
90
472
880
0.39
2.05
7
17
0.045
100
500
1000
0.5
2.5
I
VBUSQ
(Note 4)
Input Quiescent Current
2
LTC3576/LTC3576-1
ELECTRICAL CHARACTERISTICS
SYMBOL
h
CLPROG
(Note 4)
PARAMETER
Ratio of Measured V
BUS
Current to
CLPROG Program Current
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
BUS
= 5V, BAT = 3.8V, DV
CC
= 3.3V, R
CLPROG
= 3.01k, unless
otherwise noted.
CONDITIONS
1× Mode
5× Mode
10× Mode
Low Power Suspend Mode
High Power Suspend Mode
1× Mode, BAT = 3.3V
5× Mode, BAT = 3.3V
10× Mode, BAT = 3.3V
Low Power Suspend Mode
High Power Suspend Mode
Switching Modes
Suspend Modes
Rising Threshold
Falling Threshold
Rising Threshold
Falling Threshold
1×, 5×, 10× Modes, 0V < BAT < 4.2V,
I
VOUT
= 0mA, Battery Charger Off
USB Suspend Modes, I
VOUT
= 250μA
3.4
4.5
1.8
3.95
MIN
TYP
210
1160
2200
9.6
56
121
667
1217
0.31
2
1.18
100
4.30
4.00
200
50
BAT + 0.3
4.6
2.25
0.18
0.30
1× Mode (Note 5)
5× Mode (Note 5)
10× Mode (Note 5)
Closed Loop
0mA ≤ I
VBUS
≤ 500mA, V
OUT
> 3.2V
l
MAX
UNITS
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA
mA
mA
mA
mA
V
mV
I
VOUT(POWERPATH)
V
OUT
Current Available Before
Discharging Battery
0.26
1.6
0.41
2.4
V
CLPROG
V
UVLO
V
DUVLO
V
OUT
CLPROG Servo Voltage in Current Limit
V
BUS
Undervoltage Lockout
V
BUS
to BAT Differential Undervoltage
Lockout
V
OUT
Voltage
4.35
V
V
mV
mV
4.7
4.7
2.7
V
V
MHz
Ω
Ω
A
A
A
Ω
f
OSC
R
PMOS_
POWERPATH
Switching Frequency
PMOS On-Resistance
NMOS On-Resistance
R
NMOS_
POWERPATH
I
PEAK_POWERPATH
Peak Inductor Current Limit
1
2
3
10
4.75
2.9
550
680
1.8
1.38
1.15
2.5
2.6
2.8
7.2
4.2
0
3.55
4.3
1.1
30
60
BAT + 0.3
400
150
V
OUT
0
4.4
45
2.9
5.25
5.5
R
SUSP
V
BUS
V
OUT
I
VBUS
I
PEAK
I
OTGQ
V
CLPROG
V
OUT(UVLO)
t
SCFAULT
V
WALL
ΔV
WALL
V
OUT
I
WALLQ
R
ACPR
V
HACPR
V
LACPR
Suspend LDO Output Resistance
Output Voltage
Input Voltage
Output Current Limit
Peak Inductor Current Limit
V
OUT
Quiescent Current
Output Current Limit Servo Voltage
V
OUT
UVLO—V
OUT
Falling
V
OUT
UVLO—V
OUT
Rising
Short-Circuit Fault Delay
Absolute WALL Input Threshold
Differential WALL Input Threshold
Regulation Target Under V
C
Control
WALL Quiescent Current
ACPR
Pull-Down Strength
ACPR
High Voltage
ACPR
Low Voltage
PowerPath Switching Regulator—Step-Up Mode (USB On-the-Go)
V
V
mA
A
mA
V
V
V
ms
V
V
mV
mV
V
μA
Ω
V
V
3576fb
(Note 5)
V
OUT
= 3.8V, I
VBUS
= 0mA (Note 6)
V
BUS
< 4V and PMOS Switch Off
Rising Threshold
Hysteresis
WALL-BAT Falling
Hysteresis
Bat-Track Switching Regulator Control
3
LTC3576/LTC3576-1
ELECTRICAL CHARACTERISTICS
SYMBOL
PARAMETER
Overvoltage Protection
Overvoltage Protection Threshold
V
OVCUTOFF
OVGATE Output Voltage
V
OVGATE
t
RISE
Battery Charger
V
FLOAT
OVGATE Time to Reach Regulation
BAT Regulated Output Voltage
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
BUS
= 5V, BAT = 3.8V, DV
CC
= 3.3V, R
CLPROG
= 3.01k, unless
otherwise noted.
CONDITIONS
With 6.2k Series Resistor
V
OVSENS
< V
OVCUTOFF
V
OVSENS
> V
OVCUTOFF
OVGATE C
LOAD
= 1nF
LTC3576
LTC3576-1
MIN
6.1
TYP
6.35
1.88•V
OVSENS
0
2.2
4.200
4.200
4.100
4.100
1030
206
3.6
28
1.000
0.100
100
1030
100
2.85
135
–100
4
0.5
0.1
65
0.18
110
MAX
6.7
12
UNITS
V
V
V
ms
V
V
V
V
mA
mA
μA
μA
V
V
mV
mA/mA
mA
V
mV
mV
Hour
Hour
mA/mA
mV
μA
Ω
°C
l
l
I
CHG
I
BAT
Constant Current Mode Charger Current
Battery Drain Current
R
PROG
= 1k
R
PROG
= 5k
V
BUS
> V
UVLO
, Suspend Mode,
I
VOUT
= 0μA
V
BUS
= 0V, I
VOUT
= 0μA
(Ideal Diode Mode)
4.179
4.165
4.079
4.065
980
185
4.221
4.235
4.121
4.135
1065
223
6
45
V
PROG
V
PROG_TRKL
V
C/10
h
PROG
I
TRKL
V
TRKL
ΔV
TRKL
ΔV
RECHRG
t
TERM
t
BADBAT
h
C/10
V
CHRG
I
CHRG
R
ON_CHG
T
LIM
NTC
V
COLD
PROG Pin Servo Voltage
PROG Pin Servo Voltage in Trickle Charge BAT < V
TRKL
C/10 Threshold Voltage at PROG
Ratio of I
BAT
to PROG Pin Current
Trickle Charge Current
BAT < V
TRKL
, R
PROG
= 1k
Trickle Charge Threshold Voltage
BAT Rising
Trickle Charge Hysteresis Voltage
Recharge Battery Threshold Voltage
Safety Timer Termination Period
Bad Battery Termination Time
End of Charge Current Ratio
CHRG
Pin Output Low Voltage
CHRG
Pin Leakage Current
Battery Charger Power FET On-
Resistance (Between V
OUT
and BAT)
Junction Temperature in Constant
Temperature Mode
Threshold Voltage Relative to V
FLOAT
Timer Starts When V
BAT
= V
FLOAT
BAT < V
TRKL
(Note 7)
I
CHRG
= 5mA
V
CHRG
= 5V
2.7
–75
3.3
0.4
0.085
3.0
–125
5
0.6
0.112
100
1
Cold Temperature Fault Threshold Voltage Rising Threshold
Hysteresis
Hot Temperature Fault Threshold Voltage
NTC Disable Threshold Voltage
NTC Leakage Current
Forward Voltage
Internal Diode On-Resistance Dropout
Diode Current Limit
Falling Threshold
Hysteresis
Falling Threshold
Hysteresis
NTC = NTCBIAS = 5V
I
VOUT
= 10mA
I
VOUT
= 200mA
75
76.5
1.6
34.9
1.5
1.7
50
78
%NTCBIAS
%NTCBIAS
%NTCBIAS
%NTCBIAS
%NTCBIAS
mV
nA
mV
Ω
A
3576fb
V
HOT
V
DIS
I
NTC
Ideal Diode
V
FWD
R
DROPOUT
I
MAX_DIODE
33.4
0.7
–50
36.4
2.7
50
15
0.18
2
4
LTC3576/LTC3576-1
ELECTRICAL CHARACTERISTICS
SYMBOL
V
LDO3V3
R
CL_LDO3V3
R
OL_LDO3V3
V
IL
V
IH
I
PD1
I
2
C Port
DV
CC
I
DVCC
V
DVCC(UVLO)
ADDRESS
V
IH
, SDA, SCL
V
IL
, SDA, SCL
I
PD2
, SDA, SCL
V
OL
f
SCL
t
BUF
t
HD_STA
t
SU_STA
t
SU_STO
t
HD_DAT(O)
t
HD_DAT(I)
t
SU_DAT
t
LOW
t
HIGH
t
f
t
r
t
SP
V
IN1,2,3
V
OUT(UVLO)
Input Supply
DV
CC
Current
DV
CC
UVLO
I
2
C Address
Input High Threshold
Input Low Threshold
Pull-Down Current
Digital Output Low (SDA)
Clock Operating Frequency
Bus Free Time Between Stop and Start
Condition
Hold Time After (Repeated) Start
Condition
Repeated Start Condition Setup Time
Stop Condition Setup Time
Data Hold Time Output
Data Hold Time Input
Data Setup Time
SCL Low Period
SCL High Period
SDA/SCL Fall Time
SDA/SCL Rise Time
Input Spike Suppression Pulse Width
Input Supply Voltage
V
OUT
UVLO—V
OUT
Falling
V
OUT
UVLO—V
OUT
Rising
Switching Frequency
FBx Input Current
Maximum Duty Cycle
SWx Pull-Down in Shutdown
V
FB1,2,3
= 0.85V
(Note 8)
V
IN1,2,3
Connected to V
OUT
Through
Low Impedance. Switching
Regulators are Disabled in UVLO
2.7
2.5
2.6
2.8
2.25
1.3
0.6
0.6
0.6
0
0
100
1.3
0.6
20
20
300
300
50
5.5
2.9
2.7
50
10
900
I
SDA
= 3mA
2
0.4
400
70
30
SCL/SDA = 0kHz, DV
CC
= 3.3V
1.6
0.5
1.0
0001001[0]
%DV
CC
%DV
CC
μA
V
kHz
μs
μs
μs
μs
ns
ns
ns
μs
μs
ns
ns
ns
V
V
V
MHz
nA
%
kΩ
5.5
V
μA
V
PARAMETER
Regulated Output Voltage
Closed-Loop Output Resistance
Dropout Output Resistance
Logic Low Input Voltage
Logic High Input Voltage
I
LIM0
, I
LIM1
, EN1, EN2, EN3, ENOTG, SCL,
SDA Pull-Down Current
1.2
2
Always On 3.3V LDO Supply
0mA < I
LDO3V3
< 20mA
3.1
3.3
2.7
23
0.4
3.5
V
Ω
Ω
V
V
μA
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
BUS
= 5V, BAT = 3.8V, DV
CC
= 3.3V, R
CLPROG
= 3.01k, unless
otherwise noted.
CONDITIONS
MIN
TYP
MAX
UNITS
Logic (I
LIM0
, I
LIM1
, EN1, EN2, EN3, ENOTG, and SCL, SDA when DV
CC
= 0V)
General Purpose Switching Regulators 1, 2 and 3
f
OSC
I
FB1,2,3
D1,2,3
R
SW1,2,3_PD
1.8
–50
100
3576fb
5
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