LTC3577/LTC3577-1
Highly Integrated
6-Channel Portable PMIC
DESCRIPTION
FEATURES
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Full Featured Li-Ion/Polymer Charger/PowerPath™
The LTC®3577 is a highly integrated power management
IC for single cell Li-Ion/Polymer battery applications. It
includesaPowerPathmanagerwithautomaticloadpriori-
tization,abatterycharger,anidealdiode,inputovervoltage
protectionandnumerousotherinternalprotectionfeatures.
TheLTC3577isdesignedtoaccuratelychargefromcurrent
limited supplies such as USB by automatically reducing
charge current such that the sum of the load current and
thechargecurrentdoesnotexceedtheprogrammedinput
current limit (100mA or 500mA modes). The LTC3577
reduces the battery voltage at elevated temperatures to
improve safety and reliability. Efficient high current charg-
ing from supplies up to 38V is available using the on-chip
Bat-Track controller. The LTC3577 also includes a push-
button input to control the three synchronous step-down
switching regulators and system reset. The onboard LED
backlight boost circuitry can drive up to 10 series LEDs
Control with Instant-On Operation
Triple Adjustable High Efficiency Step-Down
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Switching Regulators (800mA, 500mA, 500mA I
6μA Battery Drain Current in Hard Reset
)
OUT
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Bat-Track™ Control for External HV Buck DC/DCs
2
I C Adjustable SW Slew Rates for EMI Reduction
High Temperature Battery Voltage Reduction
Improves Safety and Reliability
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Overvoltage Protection for USB (V )/Wall Inputs
BUS
Provides Protection to 30V
Integrated 40V Series LED Backlight Driver with 60dB
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Brightness Control and Gradation via I C
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1.5A Maximum Charge Current with Thermal Limiting
Battery Float Voltage:4.2V (LTC3577)
4.1V (LTC3577-1)
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Pushbutton On/Off Control with System Reset
Dual 150mA Current Limited LDOs
Small 4mm × 7mm 44-Pin QFN Package
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and includes versatile digital dimming via I C input. The
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I C input also controls two 150mA LDOs as well as other
operating modes and status read back. The LTC3577 is
available in a low profile 4mm × 7mm × 0.75mm 44-pin
QFN package.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. PowerPath and Bat-Track are trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners. Protected by U.S.
Patents including 6522118, 6700364, 7511390, 5481178, 6580258. Other Patents Pending.
APPLICATIONS
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PNDs, DMB/DVB-H; Digital/Satellite Radio;
Media Players
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Portable Industrial/Medical Products
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Universal Remotes, Photo Viewers
Other USB-Based Handheld Products
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TYPICAL APPLICATION
HV SUPPLY
LED Driver Efficiency 10 LEDs
HIGH VOLTAGE
BUCK DC/DC
8V TO 38V
(TRANSIENTS TO 60V)
90
80
70
60
OPTIONAL
100mA/500mA
1000mA
USB
V
OUT
MAX PWM
CONSTANT
CURRENT
0V
OVERVOLTAGE
PROTECTION
50
40
30
20
10
0
CC/CV
CHARGER
+
SINGLE CELL
Li-Ion
NTC
LTC3577/LTC3577-1
CHARGE
2
0.8V to 3.6V/150mA
0.8V to 3.6V/150mA
DUAL LDO
REGULATORS
2
I C PORT
LED BACKLIGHT WITH DIGITALLY
CONTROLLED DIMMING
UP TO 10 LED
BOOST
1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01
TRIPLE HIGH EFFICIENCY
STEP-DOWN SWITCHING
REGULATORS WITH
0.8V to 3.6V/800mA
0.8V to 3.6V/500mA
0.8V to 3.6V/500mA
LED CURRENT (A)
PB
3577 TA01b
PUSHBUTTON CONTROL
3577 TA01a
3577f
1