Alternative Parts


Features and Benefits

  • Seamless Transition Between Primary Power Source and Li-Ion Battery
  • 2A High Voltage Step-Down Regulator with Adaptive Output Control
  • Internal 75mΩ Ideal Diode Plus Optional External Ideal Diode Controller Provides Low Loss PowerPath When Primary Supply Not Present
  • Wide Input Voltage Range: 6V to 36V (60V Abs Max)
  • 4.45V Max Output Voltage
  • Full Featured Li-Ion Battery Charger
  • Pin Selectable 4.1V and 4.2V Charge Voltage Options
  • Thermally Enhanced Low Profile (0.75mm) 6mm × 3mm 22-Lead DFN Package

Product Details

The LTC4091 is a 36V Li-Ion battery charger and power backup manager. The integrated step-down switching regulator charges a battery from a primary power source while providing power to the load. If primary power is lost, the load is seamlessly transitioned to the backup Li-ion/polymer battery. To protect sensitive downstream loads, the maximum output voltage is 4.45V.

The LTC4091 provides an adaptive output that tracks the battery voltage for high efficiency charging. The charge current is programmable and an end-of-charge status output (CHRG) indicates full charge. Also featured is a termination timer and an NTC thermistor input used to monitor battery temperature while charging.

During backup, an internal 75mΩ ideal diode connects the battery to the load. An optional external ideal diode FET driver is available to reduce the voltage drop even further. 4.1V or 4.2V battery charge voltages can be selected.


  • Fleet and Asset Tracking
  • Automotive GPS Data Loggers
  • Automotive Telematics Systems
  • Battery Backup Systems

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

Evaluation Kits (1)

Product Recommendations

LTC4091 Companion Parts

Recommended Related Parts

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.

Sample & Buy

Sample & Buy functionality exists in desktop site
Check Inventory

The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

Price Table Help

Evaluation Boards Pricing displayed is based on 1-piece.
Up to two boards can be purchased through To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.