TI wireless charging controller touts foreign object detection
Texas Instruments has unveiled its bq500412 controller, a transmitter circuit with foreign object detection for Qi wireless charging stations. The company says the integrated Wireless Power Consortium (WPC) 1.1-compliant controller reduces component count by 50 per cent and provides smartphone users with more flexibility to charge from 5-V or 12-V charging stations. The product is shipping in volume production.
The bq500412 integrates all functions required to control wireless power delivery from the charging station to a receiver circuit used in a Qi-enabled smartphone or other device. In addition to 12-V charging pads, the circuit can be combined with a boost converter to create a 3-coil, 5-V USB charging pad, while taking advantage of a Dynamic Power Limit feature to ensure quality operation independent of the power capability of the port. The bq500412 also supports an enhanced foreign object detection scheme, which makes it easier for designers to implement the requirements of the WPC 1.1 specification.
The bq500412 features complete WPC 1.1 Qi-compliant design for 12-V, A6 charging stations with a minimum 70-mm by 20-mm: bq500412 needs minimal components, including a CSD97374 power stage integrated circuit. It also offers foreign object detection, as mandated by the WPC 1.1 specification, comes standard on the controller, which features an improved algorithm with greater accuracy of error sensing. TI's Dynamic Power Limit technology allows the transmitter to work from either a USB port or low-power adapter.
The bq500412 wireless power transmitter, which is available in volume production through TI and its worldwide network of authorised distributors, comes in a 48-pin, 7mm by 7mm QFN package with a suggested resale price of $2.93 each in 1,000-unit quantities.