LTC4089-1_15 Datasheet, PDF (1/24 Pages) Linear Technology – USB Power Manager with High Voltage Switching Charger

LTC4089-1
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}
n _{Load Dependent Charging from USB Input}
Guarantees Current Compliance
n _{215mΩ 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 4.1V 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^®4089-1 is a USB power manager plus high
voltage Li-Ion battery charger. This device controls the
total current 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 current does not exceed the programmed input
current limit. The LTC4089-1 also accommodates high
voltage power supplies, such as 12V AC-DC wall adapters,
Firewire, or automotive power.
The LTC4089-1 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.
, 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 and 6700364.
TYPICAL APPLICATION
HIGH (6V-36V)
VOLTAGE INPUT
5V (NOM)
FROM USB
CABLE V_BUS
1μF
4.7μF
HVIN
HVEN
BOOST
IN
LTC4089-1
0.1μF
SW
HVOUT
HVPR
OUT
10μH
1k
BAT
TIMER
CLPROG GND PROG
0.1μF 2k
100k
+
Li-Ion BATTERY
10μF
TO LDOs
4.7μF ^REGS^{, ETC.}
V_OUT (TYP)
5V
5V
V_BAT
AVAILABLE INPUT
HV INPUT (LTC4089-1)
USB ONLY
BAT ONLY
4089-1 TAO1
LTC4089-1 High Voltage
Battery Charger Efficiency
90
CC CURRENT = 970mA
85 NO OUTPUT LOAD
FIGURE 10 SCHEMATIC
80 _{WITH RPROG = 52k}
75
LTC4089-1
70
65
60
55
50
45
40
2.5
HVIN = 8V
HVIN = 12V
HVIN = 24V
HVIN = 36V
3
3.5
4
4.5
BATTERY VOLTAGE (V)
4089-1 TA01b
40891fa
1