LTC4058X-4.2_15 Datasheet, PDF (1/12 Pages) Linear Technology – Standalone Linear Li-Ion Battery Charger with Thermal Regulation in DFN

FEATURES
s _{Programmable Charge Current Up to 950mA}
s _{Complete Linear Charger in DFN Package}
s _{No MOSFET, Sense Resistor or Blocking Diode}
Required
s _{Thermal Regulation Maximizes Charge Rate}
Without Risk of Overheating*
s _{Battery Kelvin Sensing Improves Charging Accuracy}
s _{Charges Directly from a USB Port}
s _{C/10 Charge Termination}
s _{Preset 4.2V Charge Voltage with ±1% Accuracy}
s _{Charge Current Monitor Output for Gas Gauging*}
s _{Automatic Recharge}
s _{Charge Status Output}
s _{“AC Present” Output}
s _{2.9V Trickle Charge Threshold (LTC4058)}
s _{Available Without Trickle Charge (LTC4058X)}
s _{Soft-Start Limits Inrush Current}
s _{Low Profile (3mm × 3mm × 0.75mm) DFN Package}
U
APPLICATIO S
s _{Cellular Telephones, PDAs, MP3 Players}
s _{Bluetooth Applications}
LTC4058-4.2/LTC4058X-4.2
Standalone Linear
Li-Ion Battery Charger with
Thermal Regulation in DFN
DESCRIPTIO
The LTC^®4058 is a complete constant-current/constant-
voltage linear charger for single cell lithium-ion batteries.
Its DFN package and low external component count make
the LTC4058 ideally suited for portable applications. Fur-
thermore, the LTC4058 is designed to work within USB
power specifications.
The LTC4058 can Kelvin sense the battery terminal for
more accurate float voltage charging. No external sense
resistor or external blocking diode are required due to the
internal MOSFET architecture. Thermal feedback regu-
lates the charge current to limit the die temperature during
high power operation or high ambient temperature condi-
tions. The charge voltage is fixed at 4.2V and the charge
current is programmed with a resistor. The LTC4058
terminates the charge cycle when the charge current
drops to 10% of the programmed value after the final float
voltage is reached.
When the input supply (wall adapter or USB supply) is
removed, the LTC4058 enters a low current state dropping
the battery drain current to less than 2µA. Other features
include charge current monitor, undervoltage lockout,
automatic recharge and status pins to indicate charge
termination and the presence of an input voltage.
, LTC and LT are registered trademarks of Linear Technology Corporation.
*US Patent 6,522,118
TYPICAL APPLICATIO
Single Cell Li-Ion Battery Charger with Kelvin Sense
V_IN
4.5V TO 6.5V
600mA
V_CC
BAT
BSENSE
LTC4058-4.2
CHRG
ACPR
EN PROG
+ ^1-CELL
Li-Ion
BATTERY
1µF
GND
1.65k
405842 TA01
Complete Charge Cycle (750mAh Battery)
700
CONSTANT
CURRENT
600
500
4.75
4.50
CONSTANT
VOLTAGE 4.25
400
4.00
300
3.75
200
3.50
V_CC = 5V
100
θ_JA = 40°C/W
R_PROG = 1.65k
3.25
0 ^{TA = 25°C}
3.00
0 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0 2.25
TIME (HOURS)
405842 TA02
sn405842 405842fs
1