LTC4069EDC

The LTC4069EDC is a compact and efficient linear battery charger IC developed by Linear Technology, now part of Analog Devices. It is specifically designed for charging single-cell lithium-ion and lithium-polymer batteries, making it ideal for portable and space-constrained applications.

This charger integrates multiple functions, requiring minimal external components. It operates with input voltages up to 10V and features thermal regulation to prevent overheating during charging cycles. The device automatically adjusts charge current based on temperature for safe operation. When the battery voltage reaches the programmed float voltage, typically 4.2V for lithium-ion, it switches to constant-voltage mode. Charge termination occurs when the current drops below a preset threshold.

Key features include automatic recharge functionality and a low-battery detection function. A charge status output pin is provided for system monitoring. The LTC4069EDC is suitable for applications such as medical monitoring equipment, handheld industrial tools, and consumer electronics like Bluetooth headsets and GPS devices. Its versatility allows operation from various power sources, including USB ports and wall adapters.

Proper implementation requires attention to PCB thermal management due to heat generation from the linear charging topology. Designers should ensure adequate copper area for heat dissipation and keep input voltage within specified limits. The charger should not be operated without a battery connected unless a dummy load is provided.