Introduction: 

The 4054H is a linear charging chip with a constant voltage and constant current process for charging a single lithium battery. Its SOT23-5 and low peripheral count make the 4054H ideal for mobile portable applications. In addition, the chip is also specially developed for USB charging applications with a low battery pre-charge function. The optimised design of the internal MOSFET eliminates the need for external current-sense resistors and reverse blocking diodes. The chip's thermal protection module provides real-time protection against overheating during high-current charging and high ambient temperatures. The full charge voltage is fixed at 4.2V and the charging current can be designed through the resistor on the ISET pin. When the charging current is close to the floating voltage of the chip, i.e. when the charging current reaches 1.5/10 of the set current, the chip automatically disconnects from charging and completes the charging process. When the connected charger or PC USB is disconnected, the chip automatically enters a micro-current state, where the leakage current from the battery into the chip is less than 1uA. Other features of the 4054H include accurate detection of charging status, low voltage shutdown, automatic re-charging and an indicator to show the charging status or the charger is connected properly.

Features: 

 Definable charge current up to 600mA. 

 No MOSFETs, detection resistors, blocking diodes required.

 Complete linear charger for single cell lithium batteries.

 Constant current, constant voltage operation and thermal regulation to maximise charge rate.

 4.2V charging voltage with ±1% accuracy.

 Automatic re-charge.

 3V trickle charge threshold.

 1.5C/10 charge termination.

 Output overcurrent protection.

 Charging over temperature protection.

 SOT23-5 package.

Applications: 

 Mobile multimedia devices, MP3 .

 Mobile phones, smart phones.

 PDA, DSC. 

 Bluetooth applications.