LTC4066_15 Datasheet, PDF (1/28 Pages) Linear Technology – USB Power Controller and Li-Ion Linear Charger with Low Loss Ideal Diode

FEATURES
n _{Seamless Transition Between Input Power Sources:}
Li-Ion Battery, USB and 5V Wall Adapter
n _{Low Loss (50mΩ) Ideal Diode Path from BAT to OUT}
n _{Programmable Charge Current Detection (CHRG)}
n _{Load Dependent Charging Guarantees USB Input}
Current Compliance
n _{Analog Gas Gauge Function}
n _{Charges Single Cell Li-Ion Batteries Directly from}
USB Port
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)
n _{Termination Timer Adapts to Actual Charge Current}
n _{Preset 4.2V Charge Voltage with 0.8% Accuracy}
(4.1V for LTC4066-1)
n _{NTC Thermistor Input for Temperature Qualified}
Charging
n _{Thin Profile (0.75mm) 24-Lead 4mm × 4mm}
QFN Package
n _{Ultrathin Profile (0.55mm) 24-Lead 4mm × 4mm}
UTQFN Package (LTC4066 Only)
APPLICATIONS
n _{Portable USB Devices}
n _{GPS, Cameras, Broadband Wireless Modems}
n _{Mulitple Input Chargers}
LTC4066/LTC4066-1
USB Power Controller and
Li-Ion Linear Charger with
Low Loss Ideal Diode
DESCRIPTION
The LTC^®4066/LTC4066-1 are USB power managers and
Li-Ion battery chargers designed to work in portable
battery-powered applications. The parts control the total
current used by the USB peripheral for operation and
battery charging. The total input current can be limited
to 100mA, 500mA or “unlimited” (i.e., above 2A). 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 LTC4066/LTC4066-1 include a standalone constant-
current/constant-voltage linear charger for single cell
Li-ion batteries. The float voltage applied to the battery
is held to a tight 0.8% tolerance, and charge current
is programmable using an external resistor to ground.
A programmable end-of-charge status output (CHRG)
indicates full charge. BAT pin charge and discharge cur-
rents can be monitored via an analog output (I_STAT). Total
charge time is programmable by an external capacitor to
ground. When the battery drops 100mV below the float
voltage, automatic recharging of the battery occurs. Also
featured is an NTC thermistor input used to monitor bat-
tery temperature while charging.
The LTC4066/LTC4066-1 are available in a 24-pin thin
profile (0.75mm) 4mm × 4mm QFN package. The LTC4066
is also available in a 24-pin ultrathin profile (0.55mm)
4mm × 4mm UTQFN package.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. PowerPath
is a trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners. *Protected by U.S. Patents including 6522118.
TYPICAL APPLICATION
5V (NOM)
FROM USB
CABLE V_BUS
4.7μF
SUSPEND USB POWER
500mA/100mA SELECT
INPUT CURRENT
LIMIT DISABLE
IN
V_NTC
NTC
WALL
SHDN
LTC4066
SUSP
HPWR
CLDIS
TIMER PROG CLPROG
OUT
BAT ₊
CHRG
ACPR
POL
I_STAT
GND
510Ω 510Ω
TO ADC FOR
GAS GAUGE
0.1μF
100k 2k
2k
4066 TA01
TO LDOs,
REGs, ETC
4.7μF
600
500
I_IN
400
I_LOAD
300
200
I_BAT
CHARGING
100
0
–100
0
100 200 300 400 500 600
I_LOAD (mA)
I_BAT
(IDEAL DIODE)
4066 TA02
4066fc
1