TC4056A 1 A Single-Cell Lithium Battery Charger IC – ESOP-8

The TC4056A is an integrated circuit designed to charge a single lithium-ion or lithium-polymer cell with a nominal voltage of 3.7 V and a maximum charge voltage of 4.2 V.

It uses a constant-current/constant-voltage charging process and allows the charging current to be programmed using an external resistor. The maximum current can reach 1 A, provided the power supply, PCB design and thermal dissipation are suitable.

Integrated thermal regulation automatically reduces the charge current when the internal temperature becomes excessive, protecting the circuit and helping maintain stable operation.

Charging terminates automatically when the current falls to approximately one tenth of the programmed value after reaching the final voltage. Automatic recharge restarts the charging process when the battery voltage decreases.

Two status outputs can indicate charging and charge completion using external LEDs. The ESOP-8 package, similar to SOP-8 but with an exposed thermal pad underneath, helps transfer heat into the printed circuit board.

Main features

• Model: TC4056A
• Type: linear battery charger controller
• Compatible batteries: lithium-ion and Li-Po
• Number of cells: one
• Nominal battery voltage: 3.7 V
• Final charge voltage: 4.2 V
• Maximum charge current: up to 1,000 mA
• Charge current: programmable using an external resistor
• Charging method: constant current/constant voltage
• Recommended supply voltage: 4–5.5 V DC
• Compatible with 5 V USB power
• Charge termination: approximately C/10
• Thermal regulation: integrated
• Automatic recharge: yes
• Trickle charging for discharged cells: approximately 2.9 V
• Soft start: yes
• Reverse-current protection: integrated
• Battery temperature monitoring: available
• Status indication: charging and charge complete
• Standby supply current: approximately 55 µA
• Battery leakage without input power: below 2 µA
• Package: ESOP-8/SOP-8 with exposed thermal pad
• Mounting: SMD
• Operating temperature: –40 to +85 °C
• Sold: individually

Pin functions

• TEMP: battery temperature monitoring
• PROG: current programming and monitoring
• GND: ground
• VCC: power input
• BAT: positive battery connection
• STDBY: charge-complete indication
• CHRG: charging indication
• CE: charger enable or disable
• Exposed thermal pad: connect to ground and the PCB heat-dissipation area

Recommended applications

• USB lithium battery chargers
• Portable electronic devices
• Microcontroller projects
• Single-cell 18650 battery systems
• Single-cell Li-Po batteries
• Portable measuring equipment
• GPS devices and media players
• Charger circuit development and repair

Package contents

• 1 TC4056A integrated circuit

Important note

This product is an SMD integrated circuit, not a complete charger module. It requires a printed circuit board, external components and suitable soldering equipment.

The TC4056A controls battery charging but should not be considered a complete short-circuit, overcurrent or over-discharge protection system. Add a suitable protection circuit when using an unprotected cell.

The exposed thermal pad must be correctly soldered to a suitable PCB copper area. At charge currents close to 1 A, insufficient heat dissipation may cause the thermal regulation system to reduce the charging current significantly.

Do not use this IC with LiFePO₄ batteries, multi-cell series packs or cells with a maximum charge voltage other than 4.2 V.