Wireless charging is a new technology which can be used to charge almost any device including smartphones, tablets, wireless speakers, mice, keyboards, wearables, digital cameras, and many other battery-powered applications. This technology allows a device to charge automatically by placing it on a surface without bothering with plugs or cables. Wireless chargers, most of which are Qi-certified, deliver charge to a phone or other accesories wirelessly using magnetic induction. These chargers can be used with Qi-enabled smartphones, while there are still many cellphones that can’t charge wirelessly without using a special case or receiver. Nowadays, wireless charging can coexist with NFC (Near Field Communication) and Bluetooth, allowing for very creative solutions such as paired phones charging each other.
If you are curious to design your own wireless charger, here are some industry-standard reference designs which target a variety of applications including smartphones, automobiles, electronics point of sale terminals (ePOS), PC accesories, and more. Each design is equipped with complete documentation for quick time to market and easy development. Take a look!
1. 5W Automotive Wireless Charger For Smartphones:
This is a 5W wireless transmitter designed for automotive wireless charging applications. The design is Qi-certified as a WPC-A13 transmitter type and uses multi-coil to support any Qi-enabled smartphone. Advanced features such as NFC, CAN, touch sense, and robust foreign object detection algorithm are supported. The design also addresses automotive specific issues such as EMC, key FOB and Start/Stop. More on this Reference design.
2. NFC-enabled Wireless Charger For Bluetooth Speakers & Smartphones:
NXP offers a smart wireless charging reference design for 19V Qi transmitters. By featuring NFC (Near Field Communication), it enables advanced use cases like zero-power standby, automatic Bluetooth pairing, user-defined charger settings, and many more. Consumers can configure wireless charging pad settings via any NFC-enabled phone or tablet, and NFC could be used to trigger “tap to power on” feature of the wireless charger, for zero standby current when not in use. Other smart features include automatic Bluetooth pairing, or launching applications and web sites when an NFC-enabled phone is put on the charging pad. More on this Reference design
3. 15W Wireless Charger For Smart phones/ePOS Terminals/Battery Banks:
Freescale offers a reference design of a wireless charging transmitter with target applications including mobile phone chargers, Tablet PCs, Point-of-sale terminals, hand-held medical devices, mobile phone accessories such as battery banks and active phone sleeves. The reference design uses Freescale’s innovative wireless charging transmit controller IC to perform digital demodulation on incoming signals from the receiver. This unique feature provides a major reduction in BOM costs and reduces the PCB footprint. An additional feature of the solution is robust foreign object detection (FOD) which detects metallic objects, such as aluminum or steel objects which may be present in the charging environment. More on this Reference Design
4. Wireless Charger For Wearables:
TI’s Qi-compliant wireless charger design is suitable for low power wearable devices such as smart clothing, smart watches, ID tags, portable medical meters, ECG, etc. Designed for 135mA charge current application, the design features an ultra small size (5x15mm2), and utilizes a Qi compliant wireless receiver (bq51003) and ultra low current 1 cell Li-ion linear charger (bq25100). More on this Reference Design