Vishay introduces wireless charging Tx and Rx coils with moisture resistance up to 90% RH, saving space

     Vishay Intertechnology has announced the introduction of new wireless charging transmit (Tx) and receive (Rx) coils made of iron powder that are resistant to moisture up to 90% relative humidity. Vishay Dale IWAS3222CZEB190JR1, IWTX4646DCEB240JR1, IWTX47R0DAEB6R3JR1 and IWTX47R0EBEB240JR1 for industrial, medical and consumer electronics applications with power up to 30 W. Operating temperature up to +105 °C, occupying area reduced by 25% compared to previous generation devices and competing solutions.

     The recently released device has high resistance to moisture and its special shielding coating provides excellent environmental protection. In addition, the back of the coil uses highly saturated iron powder, which is not affected by the temperature fluctuations and inductance steep drops common in ferrite solutions. The choice of magnetic back shielding material is critical because it can be used to increase the inductance of the coil, suppress the leakage of the electromagnetic field, and maximize the directivity of the electromagnetic field.

     The IWAS3222CZEB190JR1 Rx coil is a self-adhesive enamelled wire with an inductance of 19.6mH at 200 kHz, a Q value of 28.5, and a direct current resistance (DCR) of 357 mW. The IWTX4646DCEB240JR1, IWTX47R0DAEB6R3JR1, and IWTX47R0EBEB240JR1 have inductances ranging from 6.3 to 24 mH. Tx coil DCR as low as 40 mW, Q value of 200, temperature rise current of 7 A, to maximize the receiving coil power transmission efficiency, while high saturation current of 22 A, ensuring stable inductance and performance consistency in the operating current range.

     For increased durability, the Tx coil uses silk-covered Litz wire to help prevent scratches and wire distortion, improve insulation, and reduce skin effect losses and proximity losses. In addition, the IWTX4646DCEB240JR and IWTX47R0EBEB240JR1 use Alpha winding process technology to eliminate wire crossing and reduce height as much as possible.

     Typical applications include handheld power tools and diagnostic and therapeutic devices, drones, smartphones and tablets, game consoles, and wearables. The wireless charging coils comply with RoHS and Vishay green standards, are halogen-free and are available in rectangular, square and round shapes.