LTC4089_15 Datasheet, PDF (1/24 Pages) Linear Technology – USB Power Manager with High Voltage Switching Charger

LTC4089/LTC4089-5
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 (LTC4089)
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 4.2V 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-Pin DFN Package}
APPLICATIONS
n _{Portable USB Devices—GPS Receivers, Cameras,}
MP3 Players, PDAs
DESCRIPTION
The LTC^®4089/LTC4089-5 are USB power managers plus
high voltage Li-Ion battery chargers. These devices control
the total current used by the USB peripheral for operation
and battery charging. Battery charge current is automati-
cally reduced such that the sum of the load current and
the charge current does not exceed the programmed input
current limit. The LTC4089/LTC4089-5 also accommodate
high voltage power supplies, such as 12V AC-DC wall
adapters, Firewire, or automotive power.
The LTC4089 provides an adaptive output that tracks the
battery voltage for high efficiency charging from the high
voltage input. The LTC4089-5 provides a fixed 5V output
from the high voltage input to charge single cell Li-Ion
batteries. The charge current is programmable and an
end-of-charge status output (CHRG) indicates full charge.
Also featured is 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 of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 6522118, 6700364.
TYPICAL APPLICATION
HIGH (6V-36V)
VOLTAGE INPUT
5V (NOM)
FROM USB
CABLE V_BUS
HVIN
BOOST
1μF
HVEN
IN
4.7μF
LTC4089
0.1μF
SW
HVOUT
HVPR
OUT
10μH
1k
0.1μF
TIMER
BAT
CLPROG GND PROG
2k
100k
+
Li-Ion BATTERY
LTC4089 High Voltage
Battery Charger Efficiency
90
CC CURRENT = 970mA
10μF
85 NO OUTPUT LOAD
FIGURE 10 SCHEMATIC
LTC4089
80 _{WITH RPROG = 52k}
75
70
TO LDOs
4.7μF ^REGS^{, ETC.}
65
60
LTC4089-5
VOUT (TYP)
V_BAT +0.3V
5V
5V
V_BAT
55
50
AVAILABLE INPUT
HV INPUT (LTC4089)
HV INPUT (LTC4089-5)
45
40
2.5
USB ONLY
BAT ONLY
4089 TAO1
HVIN = 8V
HVIN = 12V
HVIN = 24V
HVIN = 36V
3
3.5
4
BATTERY VOLTAGE (V)
4.5
4089 TA01b
40895fc
1