Green Design

High-Efficiency Power Manager

Linear Technology Corporation (Milpitas, CA) introduces the LTC4155, a high-power, I2C-controlled, high-efficiency PowerPath™ manager, ideal diode controller, and lithium-ion battery charger for single-cell portable devices such as tablet PCs, ultra-mobile PCs (UMPCs), personal video players, smart phones, digital cameras, PDAs, portable medical and industrial devices, and personal navigation devices.

The IC is designed to efficiently transfer up to 15W from a variety of sources while minimizing power dissipation and easing thermal budgeting constraints. The LTC4155’s switching PowerPath topology seamlessly manages power distribution from two input sources such as a wall adapter and USB port to the device’s rechargeable lithium-ion battery while preferentially providing power to the system load when input power is limited.

Because power is conserved, the LTC4155 allows the output load current to exceed the current drawn by the input supply, maximizing use of the available power for battery charging without exceeding the input supply power delivery specifications. For example, when powered from a 5V/2A wall adapter, the IC’s switching regulator efficiently transfers over 90% of the available 10W, enabling up to 2.4A charge current and resulting in faster charge times.

Unlike ordinary switching battery chargers, the LTC4155 features instant-on operation to ensure that system power is available at plug-in even with a deeply discharged battery. USB On-The-Go support provides a 5V supply back to the USB port without any additional components.

(Linear Technology Corporation)