CST4054B Overview：
    CST4054B is a comprehensive single-chip lithium-ion battery constant current/constant voltage linear power management chip.

    The thin size and small outer packaging of CST4054B make it convenient for portable applications. It is worth mentioning that CST4054B is specifically designed for USB power supply specifications. Thanks to the internal MOSFET structure, there is no need for external resistors and blocking diodes in applications. During high-energy operation and high peripheral temperature, thermal feedback can control the charging current to reduce chip temperature. The charging voltage is limited to 4.2V, and the charging current is adjusted through an external resistor. After reaching the target charging voltage, when the charging current drops to 1/10 of the set value, CST4054B will automatically end the charging process. When the input voltage (AC adapter or USB power supply) is removed, CST4054B automatically enters a low current state, reducing the battery leakage current to below 1uA. Alternatively, CST4054B can be set to shutdown mode to reduce the power supply current to 25 μ A. CST4054B ensures that the chip automatically enters a protective state when the battery is reversed, preventing the IC from being broken down and causing accidents due to battery self discharge. Other features include: charging current monitoring, input low voltage lockout, automatic recharging, and indicators of charging full and starting.

    CST4054B adopts SOT23-5L small package
 
CST4054B Feature：
The maximum charging current can reach 500mA
No need for MOSFET, sensing resistor, and blocking diode
Constant current/constant voltage operation and heat regulation enable battery tubes
The highest efficiency is achieved, and there is no risk of overheating in the battery
4.2V preset charging voltage with an accuracy of ± 1%
Integrated complete charging status display
1/10 charging current termination
The power supply current in standby mode is 25 μ A
2.9V trickle charging threshold voltage
Soft start limits surge current and current
Battery reverse connection protection
CST4054B adopts SOT23-5L small package

CST4054B Typical Application Circuit Diagram：

CST4054B引脚排列

CST4054B pin arrangement