LTC4156_15 Datasheet, PDF (1/52 Pages) Linear Technology – Dual-Input Power Manager/ 3.5A LiFePO4 Battery Charger with I2C Control and USB OTG

LTC4156
Dual-Input Power Manager/
w3.i5thAI^2LCiFeCPoOn4trBoal ^tatenrdy
Charger
USB OTG
FEATURES
n _{High Efficiency Charger Capable of 3.5A}
Charge Current
n _{Charge Control Algorithm Specifically Designed for}
LiFePO₄ Batteries (Lithium Iron Phosphate)
n _{Monolithic Switching Regulator Makes Optimal Use}
of Limited Power and Thermal Budget
n _{Dual Input Overvoltage Protection Controller}
n _{Priority Multiplexing for Multiple Inputs}
n _I²_{C/SMBus Control and Status Feedback}
n _{NTC Thermistor ADC for Temperature Dependent}
Charge Algorithms (JEITA)
n _{Instant-On Operation with Low Battery}
n _{Battery Ideal Diode Controller for Power}
Management
n _{USB On-The-Go Power Delivery to the USB Port}
n _{Four Float Voltage Settings (3.45V, 3.55V, 3.6V, 3.8V)}
n _{28-Lead 4mm × 5mm QFN Package}
APPLICATIONS
n _{Portable Medical Devices}
n _{Portable Industrial Devices}
n _{Backup Devices}
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.
DESCRIPTION
The LTC^®4156 is a 15 watt I²C controlled power manager
with PowerPath™ instant-on operation, high efficiency
switching battery charging and USB compatibility. The
LTC4156 seamlessly manages power distribution from
two 5V sources, such as a USB port and a wall adapter, to
a single-cell rechargeable lithium iron phosphate battery
and a system load.
The LTC4156’s switching battery charger automatically
limits its input current for USB compatibility, or may
draw up to 3A from a high power wall adapter. The high
efficiency step-down switching charger is designed to
provide maximum power to the application and reduced
heat in high power density applications.
I²C adjustability of input current, charge current, battery
float voltage, charge termination, and many other param-
eters allows maximum flexibility. I²C status reporting of
key system and charge parameters facilitates intelligent
control decisions. USB On-The-Go support provides 5V
power back to the USB port without any additional com-
ponents. A dual-input, priority multiplexing, overvoltage
protection circuit guards the LTC4156 from high voltage
damage on the V_BUS pin.
The LTC4156 is available in the low profile (0.75mm)
28-lead 4mm × 5mm QFN surface mount package.
TYPICAL APPLICATION
I²C Controlled High Power Battery Charger/USB Power Manager
WALLSNS
WALLGT
1µH
SW
V_OUT
TO
SYSTEM
LOAD
V_IN
V_BUS
10µF
CHGSNS
LTC4156
BATGATE
22µF
USBGT
BATSNS
3.6k
100k
USBSNS
NTCBIAS
ID
NTC
3 _{I2C IRQ GND CLPROG2 CLPROG1 PROG VC OVGCAP}
1.21k _499Ω
47nF
4156 TA01a
Switching Regulator Efficiency
100
90
80
70
60
50
40
30
20
10
0
0
V_BAT = 3.3V
0.5 1.0 1.5 2.0 2.5 3.0
LOAD CURRENT (A)
4156 TA01b
4156f
1