LTC4062 Datasheet, PDF (1/20 Pages) Linear Technology – Standalone Linear Li-Ion Battery Charger with Micropower Comparator

FEATURES
■ _{Charge Current Programmable up to 1A}
■ _{Charges Single Cell Li-Ion Batteries Directly from}
USB Port
■ _{Preset Float Voltage with ±0.35% Accuracy}
■ _{Micropower Comparator for Battery Monitoring}
■ _{Thermal Regulation Maximizes Charge Rate}
Without Risk of Overheating*
■ _{Programmable Charge Current Detection/}
Termination
■ _{Programmable Charge Termination Timer}
■ _{Smart Pulsing Error Feature}
■ _SmartStart^TM _{Prolongs Battery Life}
■ _{20µA Charger Quiescent Current in Shutdown}
■ _{Available in a Low Profile (0.75mm) 10-Lead}
(3mm × 3mm) DFN Package
U
APPLICATIO S
■ _{Handheld Computers}
■ _{Portable MP3 Players}
■ _{Digital Cameras}
, LTC and LT are registered trademarks of Linear Technology Corporation.
SmartStart is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
*Protected by U.S. Patents, including 6522118.
LTC4062
Standalone Linear Li-Ion
Battery Charger with
Micropower Comparator
DESCRIPTIO
The LTC^®4062 is a full-featured, flexible, standalone linear
charger for single-cell Lithium-Ion batteries. It is capable
of operating within USB power specifications.
Both programmable time and programmable current based
termination schemes are available. Furthermore, the CHRG
open-drain status pin can be programmed to indicate the
battery charge state according to the needs of the applica-
tion. A precise low power comparator is available even
with no power applied as long as battery voltage is higher
than 2.5V. Additional safety features designed to maxi-
mize battery lifetime and reliability include the SmartStart
charging algorithm.
No external sense resistor or external blocking diode is
required for charging due to the internal MOSFET architec-
ture. Internal thermal feedback regulates the charge cur-
rent to maintain a constant die temperature during high
power operation or high ambient temperature conditions.
The charge current is programmed with an external resis-
tor. With power applied, the LTC4062 can be put into
shutdown mode to reduce the supply current to 20µA and
the battery drain current to less than 2µA. Without power
applied, the internal low power comparator can work
sinking only 10µA from the battery.
Other features include smart recharge, USB C/5 current
programming input and undervoltage lockout.
TYPICAL APPLICATIO
800mA Single Cell Li-Ion Battery Charger
(C/10 Termination)
V_IN
4.3V TO 8V
V_CC
OUT
LTC4062
EN
C/5
TIMER
BAT
1µF
PROG
I_DET
IN⁺
619Ω
GND
BAT > 3V BAT < 3V
100k
800mA
715k
+ _{SINGLE CELL}
347k
Li-Ion BATTERY
4062 TA01
Complete Charge Cycle (1100mAh Battery)
900
4.3
800
4.2
700
4.1
600
4.0
500
3.9
400
BATTERY
VOLTAGE
BATTERY
CURRENT
3.8
300
3.7
200
100 ^VCC ^{= 5V}
T_A = 25°C
0
0 0.5 1.0 1.5 2.0
TIME (HOURS)
3.6
3.5
3.4
2.5 3.0
4062 TA01b
4062f
1