The TP4055 is a complete constant-current/constant-voltage linear charger for single cell lithium-ion batteries. Manufactured by Shenzhen Tianyuan Semiconductor Co., Ltd., this device is well-suited for portable applications. It employs a SOT package and requires few external components. It has a typical charging current of 2A.

Overview:

The TP4055 is a fully integrated single-cell lithium-ion battery charger IC. It is designed to charge single-cell lithium-ion batteries with a constant-current/constant-voltage algorithm. This means it initially charges the battery with a constant current until the battery voltage reaches a predefined level, and then it maintains that voltage while the current gradually decreases as the battery approaches full charge. This process ensures the battery is charged quickly and efficiently without being damaged. The device operates from USB power sources.

Applications:

• Mobile Phones: Charging batteries in older feature phones and basic smartphones.
• Portable Media Players: Powering and charging MP3 and MP4 players.
• Bluetooth Devices: Charging headsets, speakers, and other Bluetooth-enabled gadgets.
• Power Banks: Controlling the charging process in small-capacity power banks.
• E-Cigarettes: Charging lithium-ion batteries in electronic cigarettes.
• Small Consumer Electronics: A wide range of small, battery-powered devices.

Features:

• Programmable Charge Current: The charge current can be adjusted using an external resistor.
• Constant-Current/Constant-Voltage Operation: Ensures safe and efficient charging.
• Thermal Regulation: Protects the device from overheating during high-current charging.
• Precharge Conditioning: Detects deeply discharged batteries and applies a trickle charge to revive them.
• Automatic Recharge: Automatically restarts the charging cycle when the battery voltage drops below a threshold.
• Charge Status Output: Provides an output signal to indicate the charging status (e.g., charging, fully charged).
• SOT Package: A small outline transistor package that facilitates easy integration into compact devices.

Benefits:

• Simplified Charging Circuitry: Reduces the number of external components required for charging.
• Efficient Charging: Optimizes the charging process for lithium-ion batteries.
• Battery Protection: Prevents overcharging and deep discharge, extending battery life.
• Compact Design: The small package size enables integration into portable devices.
• Cost-Effective: Provides a complete charging solution at a reasonable cost.

Additional Details:

The TP4055 typically requires an external resistor to set the charge current. The value of this resistor is calculated based on the desired charge current. The datasheet for the TP4055 provides a detailed formula for calculating the resistor value. It's crucial to consult the datasheet for the specific operating conditions, recommended external components, and safety precautions. The device also includes thermal protection, which reduces the charge current if the junction temperature exceeds a certain threshold. This prevents the device from overheating and ensures safe operation.