TP4057 4.2V Lithium-Ion Battery Charger IC SOT-23-6

TP4057 4.2V Lithium-Ion Battery Charger IC SOT-23-6 is a highly integrated, single-cell Li-Ion battery charger specifically engineered for space-constrained, portable applications. This sophisticated device utilizes a complete constant-current/constant-voltage (CC/CV) charge algorithm, making it an ideal choice for efficiently and safely charging your batteries. Housed in the tiny SOT-23-6 package, the TP4057 requires a minimal number of external components, effectively reducing the overall solution size and simplifying PCB layout. Its high integration and thermal regulation capability ensure maximum charging current without risking damage to the chip, establishing it as a top-tier component for thin client devices, wireless headsets, and wearable electronics.

Key Features:

• Complete Linear Charger: The IC provides a full linear charging solution for single-cell lithium-ion batteries, integrating all necessary power MOSFETs and protection circuitry.
• Fixed 4.2V Charge Voltage: Precisely regulates the output voltage at 4.2V with an accuracy of ±1%, strictly adhering to the charging standards for Li-Ion cells.
• Integrated Thermal Regulation: Internally monitors the chip temperature and automatically reduces the charge current to prevent overheating, maximizing charging efficiency and reliability.
• Programmable Charge Current: You can easily program the charge current up to 500 mA using a single external resistor connected between the PROG pin and GND.
• Dual-LED Status Indication: Provides separate outputs (CHRG and STDBY) to drive LEDs, clearly indicating charging status (charging, charged, or fault).
• Tiny SOT-23-6 Package: The ultra-small SOT-23-6 package minimizes the required PCB area, supporting miniaturization in modern electronic designs.

Technical Specifications:

• Input Supply Voltage (V_IN): 4.3 V to 6 V (Absolute Max 6.5 V)
• Battery Float Voltage (V_FLOAT): 4.2 V ± 1%
• Maximum Charge Current (I_MAX): 500 mA
• Termination Current (I_TERM): Fixed at ≈ 1/10 of the programmed charge current.
• Trickle Charge Current: ≈ 1/10 of the programmed charge current (for deeply discharged batteries).
• Quiescent Current: Low ≈ 50 µA current draw when not charging, conserving battery life.
• Operating Temperature Range (T_A): −40°C to +85°C

Mechanical Specifications:

• Package Type: SOT-23-6 (Small Outline Transistor, 6-Pin)
• Mounting Style: Surface Mount Device (SMD/SMT)
• Junction Temperature (T_J): Maximum 120°C (Protected by thermal regulation)
• Moisture Sensitivity Level (MSL): JEDEC Level 3 (Typical)

Dimensions:

• Body Length (Nominal): 2.9 mm
• Body Width (Nominal): 1.6 mm
• Height (Nominal): 1.1 mm (Dimensions are for the standard SOT-23-6 package)
• Pitch: 0.95 mm (Pin-to-pin distance)

Pinout and Wiring:

• Pin 1 (TEMP): Optional. Connect to a NTC thermistor for temperature-qualified charging. Connect to GND if not used.
• Pin 2 (PROG): Connect an external programming resistor (R_PROG) to GND to set the CC charge current (I_CHRG = 1000V / R_PROG).
• Pin 3 (GND): Connect to the system and power supply ground reference.
• Pin 4 (V_IN): Connect the positive power supply input (typically 5V from USB).
• Pin 5 (BAT): Connect this pin directly to the positive terminal of the Li-Ion battery.
• Pin 6 (CHRG): Open-drain output that pulls low when the IC is actively charging.

Datasheet Reference:

• Download TP4057 4.2V Single-Cell Li-Ion Charger Datasheet

Commonly Used in:

• Wearable Technology: Smartwatches, fitness trackers, and hearing aids where size is a critical constraint.
• Wireless Peripherals: Bluetooth headsets, portable speakers, and wireless mice.
• Medical Devices: Small, portable diagnostic and monitoring equipment requiring a reliable power source.

Applications:

• USB-Powered Chargers: Efficiently managing the charging process when power is supplied via a standard 5V USB port.
• Li-Ion/Li-Polymer Battery Management: Providing safe and accurate CC/CV charging for single-cell rechargeable batteries.
• Backup Power Solutions: Integrated into devices that require a small, uninterrupted power source during charging or external power failure.

Equivalent Models:

• MCP73831 / MCP73832: Very popular, functionally similar single-cell Li-Ion/Li-Po chargers in a SOT-23-5 package (similar, but one less pin).
• LT4054 / LTC4054 (or CL4054): Another widely used 4.2V linear charger, offering comparable performance and often interchangeable in basic circuits.
• TP4056 (Used with external resistors): While the TP4056 is more common, the TP4057 offers a more integrated, compact solution with similar core functionality.

Package Includes:

• 1 x TP4057 4.2V Lithium-Ion Battery Charger IC (SOT-23-6)