Overview: CN3705 is a PWM buck mode lithium battery or lithium iron phosphate battery charge management integrated circuit that independently and automatically manages the charging of single-cell or multi-cell lithium batteries or lithium iron phosphate batteries. It features a small package size, few external components, and ease of use. CN3705 features constant current and constant voltage charging modes, making it ideal for charging lithium batteries or lithium iron phosphate batteries. In constant voltage charging mode, the constant voltage charging voltage is set by an external resistor divider network; in constant current charging mode, the charging current is set by an external resistor. For deeply discharged batteries, when the battery voltage is below 66.7% of the set constant voltage charging voltage, CN3705 performs trickle charging with 15% of the set constant current charging current. In the constant voltage charging stage, the charging current gradually decreases, and when the charging current decreases to the value set by the external resistor, the charging ends. In the charging completion state, if the battery voltage drops to 91.1% of the set constant voltage charging voltage, a new charging cycle automatically begins. When the input power is cut off or the input voltage is lower than the battery voltage, CN3705 automatically enters a low-power sleep mode. Other functions include input undervoltage lockout, battery temperature monitoring, battery overvoltage protection, and charging status indication. CN3705 is packaged in a 16-pin TSSOP package.

Product Parameters

Main Functions: 5A Multi-type Battery Charging Management Integrated Circuit

Operating Mode: Switching

Battery Type: Lithium battery, Lithium iron phosphate battery

Number of Batteries: Multiple

Output Voltage Range: 0V-27V

Input Voltage Range: 7.5V-28V

Maximum Charging Current: 5A

Operating Current: 1.7mA

Solar Power Supply: No

Thermal Modulation: No

Packaging Form: TSSOP16

Switching Frequency: 300kHz

Built-in Power Tube: No

Applications:

l Lithium iron phosphate battery charging

l Laptop computers

l Backup battery applications

l Portable industrial and medical instruments

l Power tools

l Independent battery chargers

Features ：

l Wide input voltage range: 7.5V to 28V

l Complete charging management for single-cell or multi-cell lithium batteries or lithium iron phosphate batteries

l Constant voltage charging voltage is set by an external resistor divider network

l Charging current up to 5A

l PWM switching frequency: 300KHz

l Constant current charging current is set by an external resistor

l Trickle charging for deeply discharged batteries

l Charging end current can be set by an external resistor

l Battery temperature monitoring function

l Automatic recharging function

l Charging status and charging completion status indication

l Soft start function

l Battery terminal overvoltage protection

l Operating temperature range: -40°C to +85°C

l 16-pin TSSOP package

l Lead-free, halogen-free product, RoHS compliant