LTC4089-3 Datasheet, PDF (1/24 Pages) Linear Technology – USB Power Manager with High Voltage Switching Charger

LTC4089-3
USB Power Manager with
High Voltage Switching Charger
FEATURES
n _{Seamless Transition Between Power Sources: Li-Ion}
Battery, USB, and 6V to 36V External Supply
n _{High Efficiency 1.2A Charger from 6V to 36V Input}
with Adaptive Output Control
n _{3.95V Float Voltage Improves Battery Lifespan and}
High Temperature Safety Margin
n _{Load Dependent Charging from USB Input}
Guarantees Current Compliance
n _{215m Internal Ideal Diode plus Optional External}
Ideal Diode Controller Provides Low Loss Power
Path When External Supply/USB Not Present
n _{Constant-Current/Constant-Voltage Operation with}
Thermal Feedback to Maximize Charging Rate
without Risk of Overheating
n _{Selectable 100% or 20% Current Limit (e.g., 500mA/}
100mA) from USB Input
n _{Preset 3.95V Charge Voltage with ±0.8% Accuracy}
n _{C/10 Charge Current Detection Output}
n _{NTC Thermistor Input for Temperature Qualified}
Charging
n _{Tiny (6mm × 3mm × 0.75mm) 22-Lead DFN Package}
APPLICATIONS
n _{Portable USB Devices—GPS Receivers, Cameras,}
MP3 Players, PDAs
DESCRIPTION
The LTC^®4089-3 is a USB power manager plus high voltage
Li-Ion battery charger. This device controls the total cur-
rent used by the USB peripheral for operation and battery
charging. Battery charge current is automatically reduced
such that the sum of the load current and the charge cur-
rent does not exceed the programmed input current limit.
The LTC4089-3 also accommodates high voltage power
supplies, such as 12V AC/DC wall adapters, Firewire, or
automotive power.
The LTC4089-3 provides an adaptive output that tracks
the battery voltage for high efficiency charging from the
high voltage input. This 3.95V version of the the standard
LTC4089 is intended for applications which have extended
battery lifetime requirements or those that require high
temperature (approximately >60°C) operation or stor-
age. Under these conditions, a reduced float voltage will
trade-off initial cell capacity for the benefit of increased
capacity retention over the life of the battery. The charge
current is programmable and an end-of-charge status
output (CHRG) indicates full charge. Also featured are
programmable total charge time, an NTC thermistor input
used to monitor battery temperature while charging and
automatic recharging of the battery.
L, LT, LTC and LTM are registered trademarks and Bat-Track, PowerPath and ThinSOT are
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners. Protected by U.S. Patents including 6522118, 6700364, 7733061.
TYPICAL APPLICATION
HIGH (6V-36V)
VOLTAGE INPUT
5V (NOM)
FROM USB
CABLE V_BUS
1µF
4.7µF
0.1µF
HVIN
HVEN
BOOST
0.1µF
SW
HVOUT
IN
HVPR
LTC4089-3
OUT
TIMER
BAT
CLPROG GND PROG
2k
100k
10µH
10µF
1k
TO LDOs
4.7µF ^REGS^{, ETC.}
+
Li-Ion BATTERY
V_OUT (TYP)
V_BAT + 0.3V
5V
V_BAT
AVAILABLE INPUT
HV INPUT
USB ONLY
BAT ONLY
40893 TAO1a
For more information www.linear.com/4089-3
LTC4089 High Voltage
Battery Charger Efficiency
90 _{CC CURRENT = 970mA}
85 NO OUTPUT LOAD
FIGURE 10 SCHEMATIC
80 _{WITH RPROG = 52k}
75
70
65
60
55
50
45
40
2.5
HVIN = 8V
HVIN = 12V
HVIN = 24V
HVIN = 36V
3
3.5
4
BATTERY VOLTAGE (V)
4.5
40893 TA01b
40893f
1