LTC3577_15 Datasheet, PDF (1/54 Pages) Linear Technology – Highly Integrated 6-Channel Portable PMIC

FEATURES
n _{Full Featured Li-Ion/Polymer Charger/PowerPath™}
Controller with Instant-On Operation
n _{Triple Adjustable High Efficiency Step-Down}
Switching Regulators (800mA, 500mA, 500mA I_OUT)
n _{6μA Battery Drain Current in Hard Reset}
n _{Bat-Track™ Control for External HV Buck DC/DCs}
n _I²_{C Adjustable SW Slew Rates for EMI Reduction}
n _{High Temperature Battery Voltage Reduction}
Improves Safety and Reliability
n _{Overvoltage Protection for USB (VBUS)/Wall Inputs}
Provides Protection to 30V
n _{Integrated 40V Series LED Backlight Driver with 60dB}
Brightness Control and Gradation via I²C
n _{1.5A Maximum Charge Current with Thermal Limiting}
n _{Battery Float Voltage: 4.2V (LTC3577)}
4.1V (LTC3577-1)
n _{Pushbutton On/Off Control with System Reset}
n _{Dual 150mA Current Limited LDOs}
n _{Small 4mm × 7mm 44-Pin QFN Package}
APPLICATIONS
n _{PNDs, DMB/DVB-H; Digital/Satellite Radio;}
Media Players
n _{Portable Industrial/Medical Products}
n _{Universal Remotes, Photo Viewers}
n _{Other USB-Based Handheld Products}
LTC3577/LTC3577-1
Highly Integrated
6-Channel Portable PMIC
DESCRIPTION
The LTC^®3577 is a highly integrated power management
IC for single cell Li-Ion/Polymer battery applications. It
includes a PowerPath manager with automatic load priori-
tization, a battery charger, an ideal diode, input overvoltage
protection and numerous other internal protection features.
The LTC3577 is designed to accurately charge from current
limited supplies such as USB by automatically reducing
charge current such that the sum of the load current and
the charge current does not exceed the programmed input
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
and includes versatile digital dimming via I²C input. The
I²C 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 and
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.
TYPICAL APPLICATION
HV SUPPLY
8V TO 38V
(TRANSIENTS TO 60V)
OPTIONAL
USB
OVERVOLTAGE
PROTECTION
CHARGE
2
PB
HIGH VOLTAGE
BUCK DC/DC
100mA/500mA
1000mA
0V
CC/CV
CHARGER
LTC3577/LTC3577-1 ^NTC
I²C PORT
DUAL LDO
REGULATORS
LED BACKLIGHT WITH DIGITALLY
CONTROLLED DIMMING
TRIPLE HIGH EFFICIENCY
STEP-DOWN SWITCHING
REGULATORS WITH
PUSHBUTTON CONTROL
3577 TA01a
V_OUT
+ _{SINGLE CELL}
Li-Ion
0.8V to 3.6V/150mA
0.8V to 3.6V/150mA
UP TO 10 LED
BOOST
0.8V to 3.6V/800mA
0.8V to 3.6V/500mA
0.8V to 3.6V/500mA
LED Driver Efficiency (10 LEDs)
90
80
70
60
MAX PWM
CONSTANT
50
CURRENT
40
30
20
10
0
1.E-06
1.E-05 1.E-04 1.E-03 1.E-02 1.E-01
LED CURRENT (A)
3577 TA01b
3577fa
1