The Consonance CN3781 is a battery charging management IC designed for single-cell lithium-ion and lithium-polymer batteries. It offers a complete charging solution for portable applications. It integrates a power MOSFET, a synchronous buck converter, a high-accuracy voltage regulator, and charge termination circuitry into a small package.

Applications

• Portable media players
• Mobile phones
• PDAs
• GPS devices
• E-cigarettes
• Other battery-powered applications

Features

• Input Voltage Range: 4.5V to 5.5V
• Programmable Charge Current: Up to 1.2A
• Preset 4.2V Charge Voltage with ±1% Accuracy
• Automatic Recharge
• Battery Overvoltage Protection
• Short-Circuit Protection
• Thermal Protection
• LED Status Indication for Charging and Charge Completion
• Compact Package

Benefits

• Simplified design and reduced component count for battery charging circuits.
• High charging efficiency due to synchronous buck conversion, minimizing heat generation.
• Accurate charge voltage regulation extends battery life.
• Comprehensive protection features ensure safe charging operation.
• Easy integration into portable devices due to its small size.

Technical Specifications

The CN3781 operates using a synchronous buck converter topology. It accepts an input voltage between 4.5V and 5.5V. The charge current can be programmed externally using a resistor. The IC features automatic recharge, which restarts the charging cycle when the battery voltage drops below a certain threshold. It also integrates protection mechanisms like battery overvoltage protection, short-circuit protection, and thermal protection to ensure safe and reliable operation. The charging status can be monitored via LED indicators. The chip utilizes constant current/constant voltage (CC/CV) charging, which is the standard and recommended charging method for lithium-ion batteries.