Wireless charging transmitter coil for Qi wireless charging pads

October 10, 2014 // By Paul Buckley
Vishay Intertechnology, Inc. has released a new powdered-iron-based, WPC-compliant (Wireless Power Consortium) wireless charging transmitter coil for Qi wireless charging pads.

Offering a durable construction and high permeability shielding, the new Vishay Dale IWTX-4646BE-50 provides high efficiency greater than 70 % at a 19 V input voltage when tested using WPC-compliant transmitter and receiver chipsets and a Vishay Dale IWAS-4832FF-50 receiver coil with 2.7 mm spacing.

Designed for use in conjunction with Vishay's WPC-compliant wireless receiver coils, the IWTX-4646BE-50’s high-saturation powdered iron is not affected by permanent

locating magnets. As an alternative to larger ferrite-based solutions - which can saturate in the presence of a strong magnetic field - the IWTX-4646BE-50 offers a
magnetic saturation of 50% at 4,000 gauss.

The RoHS-compliant device features inductance of 24 µH at 200 kHz with a ± 5 % inductance tolerance, DCR of 71 m (± 10 %) at + 25 °C, and Q of 185 typical at 200 kHz.

The transmitter coil features a lead length of 40 mm and tinned length of 5 mm, heat rated current of 6 A, saturation current of 20 A, and self-resonant frequency of 7 MHz. AEC-Q200 certification for use in automotive applications is pending, and expected to be complete in Q1 2015.

Samples and production quantities of the IWTX-4646BE-50 Tx coil are available now, with lead times of 14 weeks for large orders.