Qi Wireless Charging Pad Solution

BPP (Baseline Power Profile) provides up to 5W wireless charging and is the basic Qi standard. EPP (Extended Power Profile) enables faster charging up to 15W by allowing higher power transfer and more efficient communication between transmitter and receiver. EPP requires more sophisticated control and better coil coupling. The IP6808 supports both profiles, automatically negotiating the appropriate power level with the connected device.

Support both BPP and EPP for maximum compatibility. EPP devices will charge faster when using compatible transmitters.

Transmitter coil selection depends on your application requirements. For standard smartphone charging, use a 50mm diameter A11 coil with 6.3μH inductance. For smaller devices like wearables, consider smaller coils (30-40mm). For multi-device or free-position charging, use multi-coil arrays. Key parameters are inductance (must be 6.3μH ±10% for Qi compliance), Q factor (higher is better for efficiency), and construction (use Litz wire for high-frequency performance). Source coils from reputable suppliers who understand Qi requirements.

Use standard A11 coils for most applications. Contact us for coil supplier recommendations and custom coil design.

Slow wireless charging can result from several factors: Poor coil alignment reduces power transfer efficiency - ensure proper positioning. Foreign objects between coils trigger power reduction for safety. High ambient temperature causes thermal derating. Incompatible or non-Qi-certified devices may not support fast charging. Low-quality power adapters cannot supply sufficient input power. Phone cases thicker than 3-4mm reduce coupling efficiency. The IP6808 automatically optimizes power, but these factors can limit maximum charging speed.

Ensure proper alignment and remove thick cases. Use a quality power adapter rated for required input power.

Test FOD by placing various metallic objects on the charging pad and verifying that charging does not start or stops immediately. Test objects should include coins, keys, metal pens, and credit cards. Also verify that legitimate devices are not falsely detected as foreign objects. Test across the entire charging surface as FOD sensitivity may vary with position. Document all test results for Qi certification. The IP6808 allows FOD sensitivity adjustment to optimize for your mechanical design.

Conduct comprehensive FOD testing with various objects. Adjust sensitivity if needed for your design.

The input power adapter must provide sufficient power for your maximum output plus conversion losses. For 15W wireless output, use a QC 3.0 or PD adapter capable of 9V/2A or 12V/1.5A (18W+). For 10W output, a 9V/1.5A (15W) adapter is sufficient. For 5W basic charging, a standard 5V/2A USB adapter works. The IP6808 works with both QC and PD adapters - use IP2723T for automatic protocol detection and negotiation. Include input protection for over-voltage and transient suppression.

Match adapter power to your wireless output requirements. Use QC or PD adapters for fast wireless charging.

Qi certification requires testing by a WPC-authorized test lab. The process includes: Registering your product with WPC, submitting samples for compliance testing against Qi specifications, passing interoperability testing with reference receivers, and paying certification fees. Prepare by using Qi-compliant transmitter ICs (like IP6808), following WPC coil design guidelines, and conducting pre-testing with Qi test equipment. The certification process typically takes 4-8 weeks. LiTong can provide guidance on preparing for certification.

Start certification process early. Use Qi-compliant components and follow WPC guidelines. We can provide certification support.