600mA  Standalone Linear
Li-Ion Battery Charger with
Thermal Regulation in ThinSOT
General Description
The LP4054 is a complete constant-current/constant- voltage linear charger for single cell lithium-ion batteries. Its ThinSOT package and low external component count make the LP4054 ideally suited for portable applications. Furthermore, the LP4054 is specifically designed to work within USB power specifications.
No external sense resistor is needed, and no blocking diode is required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature. The charge voltage is fixed at 4.2V, and the charge current can be programmed externally with a single resistor. The LP4054 automatically terminates the ch
arge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached. When the input supply (wall adapter or USB supply) is removed, the LP4054 automatically enters a low current state, dropping the battery drain current to less than 2µA. The LP4054 can be put into shutdown mode, reducing he supply current to 25µA.Other features include charge current monitor, undervoltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage.
Ordering Information
LP4054  □□□
Package
B5:SOT23-5 Features
Programmable Charge Current Up to 800mA
No MOSFET, Sense Resistor or Blocking Diode Required
Complete Linear Charger in ThinSOT Package for
Single Cell Lithium-ion Batteries
Constant-Current/Constant-Voltage Operation with Thermal Regulation to Maximize Charge
Rate Without Risk of Overheating
Charges Single Cell Li-Ion Batteries Directly from USB Port
Preset 4.2V Charge Voltage with ± 1% Accuracy  Charge Current Monitor Output for Gas Gauging
Automatic Recharge
Soft-Start Limits Inrush Current
Available in 5-Lead SOT-23 Package
2.9V Trickle Charge Threshold
C/10 Charge Termination
25mA Supply Current in Shutdown
2.9V Trickle Charge Threshold
Applications
Portable Media Players/MP3 players
Cellular and Smart mobile phone
Charging Docks and Cradles
Bluetooth Applications
Marking Information
Please see website.
F:PB-Free
LP4054
LP4054
LP4054
LP4054
LP4054
PIN
LP4054
DESCRIPTION
CHRG 1  Open-Drain Status Output
GND 2
Ground  BAT    3  Charge Current Output  VCC
float up4
Positive Input Supply Voltage
PROG 5
Charge Current Program, Charge Current Monitor and
Shutdown Pin.
Pin Functions
CHRG (PIN 1):
Open-Drain Charge Status Output. When the battery is charging, the CHRG pin is pulled low by an internal N-channel MOSFET. When the charge cycle is completed, a weak pull-down of approximately 12µA is connected to the CHRG pin, indicating a “AC present” condition. When the LP4054 detects an undervoltage lockout condition, CHRG is forced high impedance.
GND (PIN 2): Ground. BAT (PIN 3):
Charge Current Output. Provides charge current to the battery and regulates the final float voltage to 4.2V. An internal precision resistor divider from this pin sets the float voltage which is disconnected in shutdown mode. VCC (PIN 4): Positive Input Supply Voltage. Provides power to the charger. V CC can range from 4.35V to 6.5V and should be bypassed with at least a 1µF capacitor. When V CC drops to within 30mV of the BAT pin voltage, the LP4054 enters shutdown mode, dropping IBAT to less than 2µA.
PROG (PIN 5): Charge Current Program, Charge Current Monitor and Shutdown Pin. The charge current is programmed by connecting a 1% resistor, R PROG , to ground. When charging in constant-current mode, this pin servos to 1V. In all modes, the voltage on this pin can be used to measure the charge current using the following formula:
The PROG pin can also be used to shutdown the charger. Disconnecting the program resistor from ground allows a 3µA current to pull the PROG pin high. When it reaches the 1.94V shutdown threshold voltage, the charger enters shutdown mode, charging stops and the input supply current drops to 25µA. This pin is also clamped to approximately 2.4V. Driving this pin to voltages beyond the clamp vol
tage will draw currents as high as1.5mA. Reconnecting R PROG  to ground will return the charger to normal operation.
LP4054 (TSOT23-5)
Absolute Maximum Ratings
(Over 0C ≤TJ ≤125°C and recommended supply voltage)
Note 1: Absolute Maximum Ratings are those values beyond which the life of the device may be impaired.
Note 2: The LP4054 are guaranteed to meet performance specifications from 0℃ to 70℃. Specifications over the -40℃ to 85℃ operating temperature range are assured by design, characterization and correlation with statistical process controls.
Note 3: See Thermal Considerations.
Note 4: Supply current includes PROG pin current (approximately 100µA) but does not include any current delivered to the battery through the BAT pin (approximately 100mA).
Note 5: This parameter is not applicable to the LP4054X.
Note 6: I TERM is expressed as a fraction of measured full charge current with indicated PROG resistor.

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