Features and Benefits

  • Simple, Safe Linear Charger for Single Cell Lithium Battery
  • 4.5 V to 12 V Input Voltage Range
  • Adjustable Charging Current up to 1.5 A
  • Low Cost PNP External Pass Element
  • Automatic Reverse Isolation with No External Blocking Diode
  • Output Overshoot Protection
  • Deep Discharge Precharge Mode
  • Thermal Shutdown
  • Automatic Recharge
  • Programmable Termination Timer
  • LED Charging Status Indicator
  • 4.2 V Output Voltage with ±1% Accuracy Over Line and Temperature.

Product Details

The ADP2291 is a constant-current/constant-voltage linear charger for a single cell lithium ion battery, requiring just a few components to provide a simple and safe charging system that operates from a wide 4.5 V to 12 V input voltage range. It features an internally controlled, multistep charging cycle that improves battery life.

An external, low cost, PNP provides the charging current to the battery and an external resistor sets the maximum charge current. A small external capacitor programs the maximum charge time. The controller includes an LED driver to indicate the battery charging status.

Safety features include charging stop mode for battery faults, output overshoot protection, and thermal shutdown. The ADP2291 also features automatic reverse isolation, which does not require an additional blocking diode.

The multistep charge cycle optimizes the battery charging time in a safe manner. It features a trickle charge mode for a deeply discharged cell and a fast charging mode with a maximum current of 1.5 A. The ADP2291 controls the end of charge with a 4.2 V output voltage that is 1% accurate over line and temperature. It automatically recharges the battery if the cell voltage drops. When the input supply is removed, the part enters a low current state and reduces the current drawn from the battery to below 1 µA.

The ADP2291 is available in both a small, 8-pin MSOP package and a 3 × 3 mm LFCSP package that is ideally suited for small, portable applications.

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

PCN-PDN Information

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