Features

• Switching Regulator Makes Optimal Use of Limited Power Available from USB Port to Charge Battery and Power Application
• 180mΩ Internal Ideal Diode Plus External Ideal Diode Controller Seamlessly Provide Low Loss Power Path When Input Power is Limited or Unavailable
• Automatic Charge Current Reduction Maintains 3.6V Minimum V_OUT
• Full Featured Li-Ion/Polymer Battery Charger
• V_BUS Operating Range: 4.25V to 5.5V (7V Absolute Maximum—Transient)
• 1.2A Maximum Input Current Limit
• 1.5A Maximum Charge Current with Thermal Limiting
• Bat-Track Adaptive Output Control
• Slew Control Reduces Switching EMI
• Low Profile (0.75mm) 14-Lead 4mm × 3mm DFN Package
  

Typical Application

Description

The LTC4088-1/LTC4088-2 is a high efficiency USB PowerPath TM controller and Li-Ion/Polymer battery charger. It includes a synchronous switching input regulator, a full-featured battery charger and an ideal diode. Designed specifically for USB applications, the LTC4088-1/LTC4088-2's switching regulator automatically limits its input current to either 100mA, 500mA or 1A via logic control. The LTC4088-1 powers-up with the charger off; the LTC4088-2 powers-up with the charger on.

The switching input stage provides power to VOUT where power sharing between the application circuit and the battery charger is managed. Charge current is automatically reduced to maintain a regulated 3.6V VOUT during low-battery conditions. As the battery is charged, VOUT tracks VBAT for high efficiency charging. This feature allows the LTC4088-1/LTC4088-2 to provide more power to the application and eases thermal issues in constrained applications.

An ideal diode ensures that system power is available from the battery when the input current limit is reached or if the USB or wall supply is removed. The LTC4088-1/LTC4088-2 is available in the low profile 14-Lead 4mm x 3mm x 0.75mm DFN surface mount package.