CN3791 4.5V to 28V Power Management Chip with 4A Maximum Charging Current and Maximum Power Point Tracking for Lithium Battery Charging

CN3791 is a PWM voltage reduction mode single-cell lithium battery charging management integrated circuit that can be powered by solar panels. It independently manages the charging of a single cell lithium battery and has the advantages of a small package size, few peripheral components, and simple usage. CN3791 has trickle charging, constant current, and constant voltage charging modes, making it highly suitable for lithium battery charging management. In the constant voltage charging mode, CN3791 regulates the battery voltage to 4.2V; in the constant current charging mode, the charging current is set by an external resistor. When the current output capacity of the input power supply decreases, the internal circuit can automatically track the maximum power point of the solar panel, eliminating the need for users to consider the worst-case scenario and maximizing the output power of the solar panel, making it highly suitable for applications powered by solar panels. For lithium batteries that have been deeply discharged, when the battery voltage is lower than 66.5% of the constant voltage charging voltage (typical value), CN3791 performs trickle charging with 17.5% of the set constant current charging current. During the constant voltage charging phase, the charging current gradually decreases, and when the charging current drops to 16% of the constant current charging current, the charging is completed. In the charging completion state, if the battery voltage drops to 95.5% of the constant voltage charging voltage, a new charging cycle begins automatically. When the input power supply loses power or the input voltage is lower than the battery voltage, CN3791 automatically enters sleep mode. Other functions include input low voltage latch, battery end-over-voltage protection, and charging status indication. CN3791 is packaged in a 10-pin SSOP package.

• Solar panel maximum power point tracking function
• Wide input voltage range: 4.5V to 28V
• Complete charging management for single lithium battery cell
• Charging current up to 4A
• PWM switching frequency: 300KHz
• Constant voltage charging voltage: 4.2V ± 1%
• Constant current charging current set by external resistor
• Trickle charging for deeply discharged batteries
• Automatic recharging function
• Charging status and charging completion status indication
• Soft start function
• Overvoltage protection at battery terminals
• Operating temperature range: -40°C to +85°C
• 10-pin SSOP package
• Lead-free, compliant with RoHS, halogen-free

Standard export packaging available. Customers can choose from cartons, wooden cases, and wooden pallets according to their requirements.