LTC4123 - Low Power Wireless Charger for Hearing Aids


  • Complete Low Power Wireless NiMH Charger
  • Low Minimum Input Voltage: 2.2V
  • Small Total Solution Volume
  • 1.5V, 25mA Linear Single-Cell NiMH Charger
  • Temperature Compensated Charge Voltage
  • Integrated Rectifier with Overvoltage Limit
  • Zinc-Air Battery Detection
  • Reverse Polarity Protection
  • Thermally Enhanced 6-Lead (2mm × 2mm) DFN package

Typical Application

LTC4123 Typical Application
LTC4123 Typical Application


The LTC®4123 is a low power wireless receiver and a constant-current/constant-voltage linear charger for NiMH batteries. An external programming resistor sets the charge current up to 25mA. The temperature compensated charge voltage feature protects the NiMH battery and prevents overcharging.

Wireless charging with the LTC4123 allows products to be charged while sealed within enclosures and eliminates bulky connectors in space constrained environments. The LTC4123 also makes it possible to charge NiMH batteries used in moving or rotating equipment.

The LTC4123 prevents charging of Zinc-Air batteries as well as batteries inserted with reverse polarity. The LTC4123 pauses charging if its temperature is too hot or too cold. An internal timer provides time-based charging termination.

The 2mm × 2mm DFN package and low external component count make the LTC4123 well-suited for hearing aid applications or other low power portable devices where small solution size is mandatory.


For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LTC4123EDC#PBF 2x2 DFN-6 DC6 E 05-08-1703 Yes
LTC4123EDC#TRMPBF 2x2 DFN-6 DC6 E 05-08-1703 Yes
LTC4123EDC#TRPBF 2x2 DFN-6 DC6 E 05-08-1703 Yes

LTC4123 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LTC4123EDC#PBF 2x2 DFN-6 E $3.79 Yes
LTC4123EDC#TRMPBF 2x2 DFN-6 E $3.79 $2.70 Yes
LTC4123EDC#TRPBF 2x2 DFN-6 E $3.79 $2.65 Yes
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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 Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC2302A LTC4123EDC Demo Board | A Kit to Charge a NiMH Button Cell Battery Up to 25mA at 1.5V from a 5V Wireless Transmitter $150.00
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Click here to view our complete list of demo boards


  • Hearing Aids
  • Smart Cards
  • Fitness Devices
  • Moving and/or Rotating Equipment

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