Perfect for Wearable Devices! Compact & Long-Lasting Wireless Charging Solution

Product Information

Wearable devices are becoming popular in healthcare and other fields. For such devices, waterproofing and protection against dust are requirements because they are intended to be used outdoors. These devices also need to be small, compact, and easy to wear.

Since wearable devices are used daily, it is also important for them to charge easily, without the bother of replacing a battery or physically connecting to a charging cable.

Wireless charging technology meets all these requirements.

Wireless Charging Solution

Advantages of Wireless Charging

  • No connectors or contact electrodes, so highly water and dust proof
  • Lack of connector also contributes to more compact size
  • Charge simply by placing charge receiver on top of the charge transmitter

Renesas has pushed the advantages of wireless charging further by developing a new wireless charging solution that greatly contributes to more compact size (Feature 1) and longer battery life (Feature 2).

Feature1:

All-In-One Chip Enables More Compact Size

The RAA457100 power receiver IC contains functions necessary for wireless charging all in an ultra-small 3.22 mm x 2.77 mm package (even battery protection circuit and DC-DC converter are built-in!)

Figure 1. All-in-one charge power receiver IC chip

Figure 1. All-in-one charge power receiver IC chip

Figure 2. Example of single-side mount (Even including a resistor, capacitor, and inductor it's the size of a fingertip!)

Figure 2. Example of single-side mount

Feature 2:

Highly Efficient DC-DC Converter Contributes to Longer Battery Life

In addition to battery performance and low power capabilities of the charge receiver, the ability to efficiently supply the necessary voltage from a charged lithium secondary battery wirelessly to the receiver is important for extending battery life. The DC-DC converter block built into the power receiver IC supplies power at the industry top-class efficiency of 85% (at 1 mA load).

Figure 3. Built-in highly efficient DC-DC converter

Figure 3. Built-in highly efficient DC-DC converter

Evaluation Kit Makes It Easy to Build a System

  • Development boards in kit are mounted with transmitter IC (RAA458100), power receiver IC (RAA457100), power MOSFET and other peripheral components.
  • You can evaluate wireless charging functions while monitoring rectified output voltage, battery voltage, temperature, and more from a computer using a control tool.

Figure 4. Wireless charging solution evaluation kit

Figure 4. Wireless charging solution evaluation kit

Details about wireless charging here!

Details about wireless charging

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