Overview

Features and Benefits

  • Wide Input Voltage Range: 4.4V to 40V
  • Temperature Compensated Input Voltage Regulation for Maximum Power Point Tracking (MPPT)
  • Adjustable Float Voltage 3.5V to 18V (LTC4121)
  • Fixed 4.2V Float Voltage Option (LTC4121-4.2)
  • High Efficiency: Up to 95%
  • 50mA to 400mA Programmable Charge Current
  • ±1% Feedback Voltage Accuracy
  • Programmable 5% Accurate Charge Current
  • Thermally Enhanced, Low Profile (0.75mm) 16-Lead (3mm × 3mm) QFN Package

Product Details

The LTC4121 is a 400mA constant-current/constantvoltage (CC/CV) synchronous step-down battery charger. In addition to CC/CV operation, the LTC4121 regulates its input voltage to a programmable percentage of the input open-circuit voltage. This technique maintains maximum power transfer with high impedance input sources such as solar panels.

An external resistor programs the charge current up to 400mA. The LTC4121-4.2 is suitable for charging Li-Ion/ Polymer batteries, while the programmable float voltage of the LTC4121 is suitable for several battery chemistries.

The LTC4121 and LTC4121-4.2 include an accurate RUN pin threshold, low voltage battery preconditioning and bad battery fault detection, timer termination, auto-recharge, and NTC temperature qualified charging. The FAULT pin provides an indication of bad battery or temperature faults.

Once charging is terminated, the LTC4121 signals end-ofcharge via the CHRG pin, and enters a low current SLEEP mode. An auto-restart feature starts a new charging cycle if the battery voltage drops by 2.2%.

Applications

  • Handheld Instruments
  • Solar Powered Devices
  • Industrial/Military Sensors and Devices

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.

Evaluation Kits (2)

Product Recommendations

LTC4121 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.

Discussions

LTC4121 Discussions

LTC 4121 not charg
10 week(s) ago in Power By Linear
Re: LTC4121 as a solar charger for supercaps?
12 week(s) ago in Power By Linear
Re: LTC4121 as a solar charger for supercaps?
12 week(s) ago in Power By Linear
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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.


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Evaluation Boards Pricing displayed is based on 1-piece.
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.