LTC3577-4_15 Datasheet, PDF (1/52 Pages) Linear Technology – Highly Integrated Portable Product PMIC

LTC3577-3/LTC3577-4
Highly Integrated
Portable Product PMIC
FEATURES
DESCRIPTION
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 _I²_{C Adjustable SW Slew Rates for EMI Reduction}
n _{High Temperature Battery Voltage Reduction}
Improves Safety and Reliability
n _{Overvoltage Protection Controller for USB (VBUS)/Wall}
Inputs Provide Protection to 30V
n _{Integrated 40V Series LED Back Light Driver with 60dB}
Brightness Control and Gradation via I²C
n _{1.5A Maximum Charge Current with Thermal Limiting}
n _{Battery Float Voltage: 4.2V (LTC3577-3)}
4.1V (LTC3577-4)
n _{Pushbutton ON/OFF Control with System Reset}
n _{Dual 150mA Current Limited LDOs}
n _{Start-Up Timing Compatible with SiRF Atlas IV}
Processor
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 _{Other USB-Based Handheld Products}
The LTC^®3577-3/LTC3577-4 are highly integrated power
management ICs for single cell Li-Ion/Polymer battery ap-
plications. It includes a PowerPath manager with automatic
load prioritization, a battery charger, an ideal diode, input
overvoltage protection and numerous other internal pro-
tection features. The LTC3577-3/LTC3577-4 are 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 LTC3577-3/LTC3577-4 reduce the bat-
tery voltage at elevated temperatures to improve safety and
reliability. The three step-down switching regulators and
two LDOs provide a wide range of available supplies. The
LTC3577-3/LTC3577-4 also include a pushbutton input to
control power sequencing and system reset. The onboard
LED backlight boost circuitry can drive up to 10 series
LEDs and includes versatile digital dimming via the I²C
input. The LTC3577-3/LTC3577-4 are designed to support
the SiRF Atlas IV processor and has pushbutton timing
and sequencing different from other LTC3577 versions.
The LTC3577-3/LTC3577-4 are 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 is a trademark 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
5V
ADAPTER
OPTIONAL
USB
100mA/500mA
1000mA
OVERVOLTAGE
PROTECTION
CHARGE
2
0V
CC/CV
CHARGER
LTC3577-3/LTC3577-4 ^NTC
I²C PORT
DUAL LDO
REGULATORS
LED BACKLIGHT WITH DIGITALLY
CONTROLLED DIMMING
V_OUT
+ _{SINGLE CELL}
Li-Ion
0.8V to 3.6V/150mA
0.8V to 3.6V/150mA
4 TO 10 LED
BOOST
TRIPLE HIGH
PB
PUSHBUTTON
CONTROL
EFFICIENCY
STEP-DOWN
SWITCHING
0.8V to 3.6V/800mA
0.8V to 3.6V/500mA
0.8V to 3.6V/500mA
REGULATORS
357734 TA01a
LED Driver Efficiency (10 LEDs)
90
80
70
60
MAX PWM
CONSTANT
50
CURRENT
40
30
20
10
0
1000
100 10
1
0.1 0.01
LED CURRENT (mA)
357734 TA01b
357734fb
1