Linear Technology introduced The LTC4088 is an autonomous, high-efficiency power manager, diode controller, and battery charger for portable USB devices. The charger, developed by Linear Technology, features a switching front-end topology with PowerPath control.
PowerPath optimises the USB port’s power in order to charge the battery and power the application device with minimum power dissipation. This feature helps ease thermal-management issues in space-constrained media players, digital cameras, PDAs, GPS units, and smart phones. In addition, the IC allows the load current to exceed the current drawn from the USB port while conforming to USB load specifications.
Featuring an input voltage range of 4.25 to 5.5V, the LTC4088 automatically limits its input current to a maximum of 1X (for USB 100mA), 5x (for USB 500mA) or 10X for wall-adapter-powered applications (1A).
If the power source is removed, the IC ensures that system power is available from the battery to the application’s load via current flow through an internal low loss 200mΩ ideal diode, minimising voltage drop and power dissipation.
An optional external ideal diode controller is provided for driving a PFET. That reduces the overall ideal diode impedance below 40mΩ.