CST4084 General Description:
The CST4084 is a complete constant-current/constant-voltage linear charger for single cell lithium-ion batteries.
Its SOT package and low external component count make the CST4084 ideally suited for portable applications. Furthermore, the CST4084 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 CST4084 automatically terminates the charge 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 CST4084 automatically enters a low current state, dropping the battery drain current to less than 1μA.
The CST4084 can be put into shutdown mode, reducing the supply current to 35μA. 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.
CST4084 Features:
Constant-Current/Constant-Voltage Operation with Thermal Regulation to Maximize Charge Rate Without Risk of Overheating
No MOSFET, Sense Resistor or Blocking Diode Required
Complete Linear Charger in SOT Package for Single Cell Lithium-Ion Batteries
Charges Single Cell Li-Ion Batteries Directly from USB Port
Charge Current Monitor Output for Gas Gauging
Programmable Charge Current Up to 800mA
Charge Status Output Pin
C/10 Charge Termination
Automatic Recharge
Preset 4.2V Charge Voltage with ±1% Accuracy
35µA Supply Current in Shutdown
2.9V Trickle Charge Threshold
Soft-Start Limits Inrush Current
Available in 5-Lead SOT-23 Package
RoHS Compliant and Lead (Pb) Free
CST4084 Applications:
Cellular Telephones
Charging Docks and Cradles
Bluetooth Application
Wearable Application
CST4084Typical Application Circuit:
CST4084Pin Configuration:
CST4084Pin Description:
CST4084 Order Information:
CST4084Typical Application Circuit:
CST4084Pin Configuration:
CST4084Pin Description:
CST4084 Order Information:
Marking
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Part No.
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Model
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Description
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Package
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T/R Qty
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C84AS
|
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cst4084
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cst4084 Linear Li-Ion Battery Charger, 800mA, Preset 4.2V, 1 Charge Status, SOT23-5 |
SOT23-5
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3000 PCS
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CST4084Functional Block Diagram: