CN3166

CN3166 is a single-cell lithium battery charge management IC with an internal power transistor that performs constant-current and constant-voltage charging. The internal fixed constant-voltage charging voltage is 4.2V, adjustable upward via external resistors — e.g., to 4.35V or 4.4V for ternary lithium battery charging. Charge current is set by an external resistor, with a maximum continuous charge current of up to 950mA, requiring no external blocking diode or current-sense resistor. An integrated adaptive charge current module automatically adjusts the charge current based on the input power source's current output capability, making it suitable for lithium battery charging applications powered by current-limited sources such as solar panels. The IC includes two open-drain status indicator outputs. An internal power management circuit automatically reduces the charge current when the junction temperature exceeds 132°C. Charging begins when the input voltage exceeds both 4.4V and the battery voltage, with different charging modes applied based on the voltage detected at the battery voltage sense pin. The charge termination threshold is 11.2% of the constant-current charge current. When the input voltage is lost or falls below the battery voltage, the IC enters a low-power sleep mode with battery terminal current consumption below 3uA.

Applications

• Wireless earphones
• Wearable devices
• Beauty and personal care devices
• Medical instruments
• Electric toothbrushes

Key features

• Integrated adaptive charging current module — automatically adjusts charging current based on input voltage source current output capability; compatible with limited-current sources such as solar panels
• Input voltage range: 4.4V ~ 6V
• No external blocking diode or current sense resistor required
• Constant voltage charging at 4.2V; adjustable upward via a single external resistor to 4.35V or 4.4V — suitable for NMC lithium battery charging
• Configurable continuous constant current charging up to 950mA
• Overcurrent protection on charging current prevents damage from ISET pin short circuit or incorrect use of abnormally low-value resistors
• Can be used as a voltage source
• Internal soft-start circuit
• Trickle charge mode at low battery voltage — activates deeply discharged batteries and reduces power consumption
• CC/CV/constant temperature charging mode — maximizes charging current and prevents overheating
• Automatic entry into low-power sleep mode upon power supply dropout
• Dual status indicator outputs: charging status and charge termination status
• Auto-recharge
• JEITA-compliant battery temperature monitoring
• Package: 2mm x 3mm DFN-8
• Lead-free, RoHS compliant, halogen-free