Overview: The CN3312A/B/C is a PFM boost dual-cell lithium battery charge control integrated circuit operating at 4.5V to 6.5V. The CN3312A/B/C uses constant current and quasi-constant voltage mode (Quasi-CVTM) to manage battery charging. It integrates a reference voltage source, current detection resistor, inductor current detection unit, battery voltage detection circuit, P-channel field-effect transistor, and external field-effect transistor drive circuit, etc., featuring few external components and simple application. When the input power is turned on, the CN3312A/B/C enters the charging state, controlling the external N-channel MOSFET to turn on, and the inductor current rises. When it rises to the upper limit of the inductor current, the external N-channel MOSFET turns off, and the inductor current decreases, transferring the energy in the inductor to the battery. When the inductor current drops to the lower limit, the external N-channel MOSFET turns on again, and this cycle repeats. The inductor current (input current) in the constant current mode of the CN3312A/B/C is set internally to 2.65A, 1.75A, and 1A respectively by the internal current detection resistor, and can also be reduced by an external resistor. When the BAT pin voltage first reaches 8.4V (typical value), the CN3312 enters quasi-constant voltage charging mode and charges the battery with a smaller current. In quasi-constant voltage mode, when the BAT pin voltage reaches 8.4V, the charging process ends, and the external N-channel MOSFET remains off. When the BAT pin voltage drops to the recharge threshold, it enters the charging state again. When the battery voltage is lower than the input voltage, the CN3312A/B/C continues to charge the battery with a smaller current, protecting the battery. Other functions include chip enable input, chip over-temperature protection, JEITA standard compliant battery temperature monitoring function, and status indication. The CN3312A/B/C uses an 8-pin heat-enhanced eSOP package.

Product Parameters

Main functions: PFM boost dual-section lithium battery charging control integrated circuit

Operating mode: Switching

Battery type: Lithium-ion battery

Number of batteries: 2

Output voltage range: 0-8.4V

Input voltage range: 4.5V-6.5V

Operating current: 280uA

Solar power supply: Yes

Thermal modulation: Yes

Packaging form: eSOP8

Maximum output power: 8.25W

Built-in Power tube: Built-in PMOS