KF5404D is a complete constant-current/constant voltage lin ear charg er for sin gle cell lithi um-ion batterie s. Furthermore the KF5404D is speci fi cally designed to work within USB power specifications.
No external sense resistor is needed and no blo-cking diode is required due to the intermal PMOSFET 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 4.34V,and the charge current can be programmed externally with a single resistor.The KF5404D automatically terminates the charge cycle when the charge current drops to 1/10h the prog-rammed value after the final f loat voltage is reached.
When the in put supp ly (wa II ada pter or USB sup-ply) is removed the KF5404D auto matical ly enters a low curren t state dropping the battery drain current to less than 2μA.The KF5404D can be put into shutdown mode reducing the supply current to 55μA.
Other features include charge current monitor, und-ervoltage lockout, automatic recharge and a status.
Features
Protection of battery cell reverse connection
No MOSFET sense resistor or blocking diode required
Complete Linear Charger in ThinSOT Package for Single Cell Lithium-lon Batteries
Constant- Current/Constant-Voltage operation with thermal regulation to maximize Rate Without risk of overheating.
Preset 4.34V charge voltage with +1% accuracy
Automatic Recharge
Charges Single Cell Li-lon Batteries Directly from USB Port
C/10 charge termination
55μA supply current in shutdown
2.9V trickle current charge threshold
Soft-Start limits inrush current
Charge Status Output Pin
Available in SOT-23 -5 Package
Application
Cellular Telephones, PDAs, MP3 Players
Charging Docks and Cradles
Bluetooth Applications