SE9018-HF

SE9018 is a single-cell lithium battery charge management IC that accepts solar panels, standard adapters, and USB interfaces as input sources. It employs a constant current/constant voltage (CC/CV) charging mode to manage the entire charging process, with integrated Maximum Power Point Tracking (MPPT) functionality. When the input power changes, it automatically tracks the maximum power point of the input source to charge the lithium battery, while also featuring constant-temperature charging. When the charging power is excessive or the battery/IC temperature is too high, it automatically reduces the charging current to maintain a constant temperature, ensuring normal charging operation. By adopting an internal PMOSFET architecture along with a reverse-charge prevention circuit, no external isolation diode is required. The full-charge voltage is fixed at 4.2V, and the charging current can be set externally via a single resistor. The IC primarily charges the battery rapidly in constant current mode; when the battery voltage reaches the full-charge voltage, it transitions to constant voltage mode, with the current gradually decreasing. When the charging current drops to 1/10 of the set value, the charging process terminates automatically. When the input voltage (AC adapter or USB power) is removed, the IC automatically enters a low-current state, reducing battery leakage current to below 1uA. It can also be placed in shutdown mode while power is present, reducing the supply current to 30uA. Additional features include battery temperature monitoring, undervoltage lockout (UVLO), automatic recharge, and two LED status pins for indicating charging and charge completion.

Applications

• Backup power / mobile power banks
• Mobile phones, PDAs, GPS devices
• MP3, MP4 players
• Digital cameras, electronic dictionaries
• Portable devices, various chargers

Key features

• Programmable charge current up to 1000mA
• Maximum Power Point Tracking (MPPT)
• No MOSFET, sense resistor, or blocking diode required
• Input surge voltage protection 10V
• Complete linear charger for single-cell Li-Ion batteries
• Constant current/constant voltage operation with thermal regulation for maximizing charge rate without risk of overheating
• 4.2V/4.35V preset float voltage accuracy ±1%
• Charge current monitor output for battery fuel gauging
• Automatic recharge
• Dual charge status output, battery absent and fault status indication
• C/10 charge termination
• Supply current in standby mode: 70uA
• 2.9V trickle charging
• Soft-start limits inrush current
• Battery temperature monitoring
• Available in PSOP8, SOT23-6, DFN2*2-6 packages