ADP2291 Compact, 1.5 A Linear Charger for Single-Cell Li+ Battery

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 temp-erature. 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.

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.
Power Management
Data Sheets
Documentnote
ADP2291: Compact, 1.5 A Linear Charger for Single-Cell Li+ Battery Data Sheet (Rev. A)PDF 420 kB
Order Information
Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
ADP2291ARMZ-R7 Production8 ld MSOPREEL 1000-40 to 125C01.37Y
ADP2291: Compact, 1.5 A Linear Charger for Single-Cell Li+ Battery Data Sheet (Rev. A) adp2291