FBC4068YDFN8G/TR

The FBC4068 is a single-cell Li-ion battery constant-current/constant-voltage linear charger with up to 30V input voltage rating and OVP function. Its simple external application circuit makes it ideal for portable device applications, compatible with both USB power and adapter power sources. The FBC4068 is a linear charger designed specifically for single-cell Li-ion or lithium polymer batteries. The IC integrates a power transistor, and the charge current can be programmed via an external resistor, with a maximum continuous charge current of 1000 mA — no blocking diode or current sense resistor is required. The FBC4068 includes an open-drain status pin to indicate charging in progress or charge completion. During charging, the CHRG pin is pulled low to indicate that charging is in progress; once charging is complete, the CHRG pin goes to a high-impedance state. If the battery voltage falls below 2.9V, the FBC4068 applies a trickle charge at a reduced current. Once the battery voltage exceeds 2.9V, the device enters constant-current mode, with the charge current determined by resistor RPROG connected between the PROG pin and GND. As the battery voltage approaches 4.2V, the charge current gradually decreases and the FBC4068 transitions to constant-voltage mode. The charge cycle terminates when the charge current decreases to the end-of-charge threshold, which is 20% of the constant-current charge value. When the battery voltage drops below the recharge threshold of 4.05V, the FBC4068 automatically initiates a new charge cycle. The on-chip high-precision voltage reference, error amplifier, and resistor divider network ensure the battery terminal regulation voltage accuracy is within 1%, meeting the requirements of Li-ion and lithium polymer batteries. When the input voltage falls below the UVLO threshold or drops below the battery voltage, the charger enters a low-power shutdown mode in which the current drawn from the battery is less than 2µA. The FBC4068's internal thermal regulation circuit automatically reduces the charge current when the junction temperature exceeds 135°C. This feature allows users to maximize the IC's power handling capability without concern about damage to the IC or external components due to overheating. As a result, users can design the charge current based on typical conditions rather than worst-case scenarios, since the FBC4068 will automatically reduce the charge current under worst-case conditions.

Applications

• Charging dock
• Bluetooth headsets, GPS
• Mobile phones, PDA, MP3/MP4
• Digital cameras, mini speakers, and other portable devices

Key features

• Integrated PMOSFET architecture with reverse charge protection circuit — no external isolation diode required
• Thermal feedback automatically adjusts charge current to limit die temperature during high-power operation or elevated ambient temperature conditions
• Charge termination voltage: 4.2V; charge current programmable via external resistor
• Automatically terminates charging when charge current drops to 1/5 of the programmed value
• Automatically enters low-current sleep state with current dropping to 0 when input voltage is removed
• Maximum input voltage: 30V
• Full-charge voltage: 4.2V
• Overvoltage protection threshold: 7.3V
• Maximum charge current: 1000 mA
• Three-stage charging: trickle / constant current / constant voltage
• No external MOSFET, sense resistor, or isolation diode required
• Intelligent thermal regulation for maximum charge rate optimization
• Intelligent recharge function
• BAT input reverse-polarity protection
• Standby mode quiescent current: 1.2 μA
• C/5 charge termination
• 2.9V trickle charge threshold
• Charge status indication
• Package: DFN2×2_8L