Linear Technology's LTC1732EMS-4.2 Battery Charger IC

The LTC1732EMS-4.2 is a high-performance, single-cell lithium-ion (Li-Ion) battery charger integrated circuit (IC) designed by Linear Technology, which is now part of Analog Devices. This sophisticated IC is tailored to deliver reliable and efficient charging solutions for portable electronic devices, such as smartphones, digital cameras, and other USB-powered gadgets.

Key Features

• Precision Charging: The LTC1732EMS-4.2 offers precise end-of-charge voltage control, ensuring the battery is charged to 4.2V with an accuracy of ±1%. This precision helps maximize battery capacity and longevity.
• Programmable Charge Current: Users can set the charge current from 150mA to 1A via a single resistor, providing flexibility to accommodate various battery capacities and charging speed requirements.
• Charge Termination: The IC includes an automatic charge termination feature based on the C/10 principle, which stops the charging process when the current falls to one-tenth of the programmed value, ensuring safety and preventing overcharging.
• Thermal Regulation: To maintain optimal operating temperatures and enhance safety, the LTC1732EMS-4.2 integrates a thermal regulation mechanism that reduces charge current in the event of excessive heat.

Power Management and Safety

The LTC1732EMS-4.2 is equipped with several safety features to protect both the battery and the charging system. These include automatic recharge, thermal shutdown, and battery temperature sensing which, when used with an external thermistor, can suspend charging if the battery becomes too hot or too cold. Additionally, the IC features undervoltage lockout, which prevents charging if the input voltage is too low, ensuring stable and safe operation.

Compact and Efficient Design

Designed in a low-profile (0.8mm) 10-lead MSOP package, the LTC1732EMS-4.2 is ideal for space-constrained applications. Its high switching frequency allows the use of small, low-cost capacitors and inductors, minimizing the overall footprint and cost of the charging circuit.

Conclusion

The LTC1732EMS-4.2 from Linear Technology is a versatile and robust solution for single-cell Li-Ion battery charging applications. Its precision, programmability, and comprehensive safety features make it an excellent choice for designers looking to incorporate a reliable charging system into their portable electronic devices.