LTC3576 Datasheet, PDF (1/48 Pages) Linear Technology – Switching Power Manager with USB On-the-Go + Triple Step-Down DC/DCs

LTC3576/LTC3576-1
FEATURES
Switching Power Manager
with USB On-the-Go + Triple
Step-Down DC/DCs
DESCRIPTION
n _{Bidirectional Switching Regulator with Bat-}
Track™ Adaptive Output Control Provides Efficient
Charging and a 5V Output for USB On-The-Go
n _{Bat-Track Control of External High Voltage Step-}
Down Switching Regulator
n _{Overvoltage Protection Guards Against Damage}
n _{“Instant-On” Operation with Discharged Battery}
n _{Triple Step-Down Switching Regulators with I}²_C
Adjustable Outputs (1A/400mA/400mA I_OUT)
n _{180mΩ Internal Ideal Diode + External Ideal Diode}
Controller Powers the Load in Battery Mode
n _{Li-Ion/Polymer Battery Charger (1.5A Max ICHG)}
n _{Battery Float Voltage: 4.2V (LTC3576), 4.1V (LTC3576-1)}
n _{Compact (4mm × 6mm × 0.75mm) 38-pin QFN Package}
APPLICATIONS
n _{HDD-Based Media Players}
n _{GPS, PDAs, Digital Cameras, Smart Phones}
n _{Automotive Compatible Portable Electronics}
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 I²C 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 and LTM 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.
TYPICAL APPLICATION
High Efficiency PowerPath Manager with Overvoltage Protection
and Triple Step-Down Regulator
AUTOMOTIVE
FIREWIRE, ETC.
LT3653
USB OR
5V AC
ADAPTER
CHARGE
OVERVOLTAGE
PROTECTION
EXTERNAL HIGH VOLTAGE
BUCK CONTROLLER
USB COMPLIANT
BIDIRECTIONAL
SWITCHING
REGULATOR
CC/CV
BATTERY
0V
CHARGER
LTC3576/LTC3576-1
TO OTHER
LOADS
OPTIONAL
+
T
Li-Ion
ENABLE ⁶
CONTROLS
ALWAYS ON LDO
TRIPLE
1
HIGH EFFICIENCY
STEP-DOWN
2
SWITCHING
REGULATORS
3
I²C PORT
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
I²C
3576 TA01
PowerPath Switching Regulator Efficiency
to System Load (P_VOUT/P_VBUS)
100
90
80
BAT = 4.2V
70
BAT = 3.3V
60
50
40
30
20 _{VBUS = 5V}
10 ^IBAT ^{= 0mA}
10x MODE
0
10
100
LOAD CURRENT (mA)
1000
3576 TA01b
3576f
1