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  2. Power Management
  3. Battery Management
  4. Wireless Power Transfer
  5. LTC4120

Data Sheet Rev. G
PDF
JP Rev. D
User Guide
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Alternative Parts

LTC4123
LTC4123

Low Power Wireless Charger for Hearing Aids

Overview

Features and Benefits

  • Dynamic Harmonization Control Optimizes Wireless Charging Over a Wide Coupling Range
  • Wide Input Voltage Range (12.5V to 40V)
  • Adjustable Float Voltage (3.5V to 11V)
  • Fixed 4.2V Float Voltage Option (LTC4120-4.2)
  • 50mA to 400mA Charge Current Programmed with a Single Resistor
  • ±1% Feedback Voltage Accuracy
  • Programmable 5% Accurate Charge Current
  • No Microprocessor Required
  • No Transformer Core
  • Thermally Enhanced, Low Profile 16-Lead (3mm × 3mm × 0.75mm) QFN Package

Product Details

The LTC4120 is a constant-current/constant-voltage wireless receiver and battery charger. An external programming resistor sets the charge current up to 400mA. The LTC4120-4.2 is suitable for charging Li-Ion/Polymer batteries, while the programmable float voltage of the LTC4120 accommodates several battery chemistries. The LTC4120 uses a Dynamic Harmonization Control (DHC) technique that allows high efficiency contactless charging across an air gap.

The LTC4120 regulates its input voltage via the DHC pin. This technique modulates the resonant frequency of a receiver tank to automatically adjust the power received as well as the power transmitted to provide an efficient solution for wirelessly charging battery-powered devices.

Wireless charging with the LTC4120 provides a method to power devices in harsh environments without requiring expensive failure-prone connectors. This allows products to be charged while locked within sealed enclosures, or in moving or rotating equipment, or where cleanliness or sanitation is critical.

This full featured battery charger includes 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 LTC4120 signals end-of-charge 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
  • Industrial/Military Sensors and Devices
  • Harsh Environments
  • Portable Medical Devices
  • Physically Small Devices
  • Electrically Isolated Devices

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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 (3)

Documentation & Resources

  • View All (15)
  • Data Sheet (1)
  • Reliability Data (1)
  • Application Note (3)
  • User Guide (2)
  • Frequently Asked Question (1)
  • Product Selector Card (2)
  • Solutions Bulletin & Brochure (1)
  • Video (1)
  • Technical Article (3)
    • Document Type

    Tools & Simulations

    LTspice

    LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

    To launch ready-to-run LTspice demonstration circuits for this part:

    Step 1: Download and install LTspice on your computer.

    Step 2: Click on the link in the section below to download a demonstration circuit.

    Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

    LTspice

    LTspice Simulations

    LTC4120 Demo Circuit - Wireless Power Receiver with 800mA Buck Battery Charger

    Models for the following parts are available in LTspice:

    LTC4120

    Product Recommendations

    LTC4120 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.View our quality and reliability program and certifications for more information.

    Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
    LTC4120EUD#PBF Material Declaration Reliability Data 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP)
    LTC4120EUD#TRPBF Material Declaration Reliability Data 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP)
    LTC4120EUD-4.2#PBF Material Declaration Reliability Data 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP)
    LTC4120EUD-4.2#TRPBF Material Declaration Reliability Data 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP)
    LTC4120IUD#PBF Material Declaration Reliability Data 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP)
    LTC4120IUD#TRPBF Material Declaration Reliability Data 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP)
    LTC4120IUD-4.2#PBF Material Declaration Reliability Data 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP)
    LTC4120IUD-4.2#TRPBF Material Declaration Reliability Data 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP)
    Wafer Fabrication Data R577 Reliability Data

    Support & Discussions

    LTC4120 Discussions

    RE: Heat issue on LTC4125 and LTC4120
    LTC4125 - demo kit 2330A modified with smaller coil, high power consumption when receiver not in range
    All LTC4120 Discussions
    LTC4120 Contact ADI Technical Support »
    LTC4120 Ask your question »
    LTC4120 Contact ADI Technical Support » LTC4120 Ask your question »

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    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.

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