LTC4068EDD-4.2#PBF
Overview
The LTC4068EDD-4.2#PBF is a fully integrated single-cell lithium-ion battery charger from Analog Devices. Designed for space-constrained applications, this IC incorporates all necessary charging functions while requiring minimal external components. Its compact DFN package makes it ideal for portable devices where board space is at a premium. The charger operates from a 4.5V to 6.5V input range and delivers up to 800mA of charge current. It implements a complete constant-current/constant-voltage charging algorithm with automatic termination, making it suitable for a wide range of lithium-ion battery-powered applications.
Structure and Working Principle
The LTC4068EDD-4.2#PBF integrates a power MOSFET, current sense circuitry, and thermal regulation in a single chip. The device follows a standard CC/CV charging profile, beginning with constant current charging until the battery voltage reaches 4.2V, then transitioning to constant voltage mode. Internal thermal feedback reduces the charge current when the die temperature exceeds approximately 115°C, protecting both the IC and the battery. The charger automatically enters a low-current mode when the battery is fully charged and will restart charging if the battery voltage falls below 4.1V.
Key Features
Among its notable features, the LTC4068EDD-4.2#PBF offers programmable charge current through an external resistor, allowing flexibility for different battery capacities. The IC includes built-in safety timers to prevent overcharging and features a low-battery preconditioning mode for deeply discharged cells. The device also provides status outputs for charge indication and can operate in a 100mA USB-compatible mode. Its high switching frequency (up to 2MHz) enables the use of small external components, further reducing the solution footprint.
Application Areas
This battery charger IC finds extensive use in portable electronic devices such as smartphones, tablets, and digital cameras. Its precision charging capabilities make it suitable for medical devices where reliable battery performance is critical. Industrial applications include handheld test equipment, portable data loggers, and wireless sensor nodes. The LTC4068EDD-4.2#PBF is particularly valuable in space-constrained designs where board area and component count must be minimized.
Maintenance and Precautions
Proper PCB layout is crucial for optimal performance of the LTC4068EDD-4.2#PBF. The IC's exposed pad must be properly soldered to a copper ground plane for adequate thermal dissipation. Input bypass capacitors should be placed as close as possible to the VIN pin. When designing with this charger, pay special attention to battery temperature monitoring if operating in extreme environments. While the IC includes thermal regulation, additional temperature sensing may be required for applications subject to wide ambient temperature variations.
B2B Procurement Guide
When sourcing the LTC4068EDD-4.2#PBF, verify the manufacturer's part number suffix to ensure correct packaging (typically supplied in tape and reel). Consider lead time implications, as this is a specialized component that may have longer procurement cycles than standard parts. For high-volume applications, negotiate directly with authorized distributors or the manufacturer for quantity pricing. Always request recent date codes to avoid receiving obsolete or near-end-of-life stock.