## Technical Overview: P9222-R Wireless Power Receiver The **P9222-R** is a highly integrated, small-form-factor wireless power receiver (Rx) developed by Renesas Electronics (formerly IDT). It is specifically designed for mobile devices, wearables, and small battery-powered applications. --- ### 1. Key Technical Specifications The P9222-R is optimized for efficiency and space-constrained designs. Below are the primary technical parameters: | Parameter | Specification | |:---|:---| | **Power Rating** | Up to 5W | | **Compatibility** | WPC Qi 1.2.4 Baseline Power Profile (BPP) | | **Output Voltage** | Adjustable (default 5V) | | **Interface** | I2C Serial Interface | | **Package** | WLCSP (2.28 mm x 3.38 mm) | | **Efficiency** | Up to 85% AC-to-DC | --- ### 2. Core Internal Components The IC integrates several critical electronic stages to convert magnetic fields into usable DC power: 1. **Full-Bridge Synchronous Rectifier:** Converts the AC voltage induced in the receiver coil into a DC voltage with minimal heat loss. 2. **Low Dropout Regulator (LDO):** Provides a stable, regulated output voltage to charge batteries or power the system. 3. **Embedded Microcontroller (ARM Cortex-M0):** Manages communication with the transmitter (Tx) and handles Qi protocol handshaking. 4. **Foreign Object Detection (FOD):** Uses internal sensing to detect metal objects between the coil and the charger to prevent overheating. 5. **ADC (Analog-to-Digital Converter):** Monitors voltage, current, and temperature for real-time protection. --- ### 3. Application Circuit Components When designing with the P9222-R, the following external components are required: * **Receiver Coil:** An external copper inductor (L) that captures the electromagnetic field. * **Resonant Capacitors ($C_s$ and $C_d$):** Used to tune the coil to the specific frequency required by the Qi standard (usually 110-205 kHz). * **Decoupling Capacitors:** Placed at the output ($V_{out}$) to filter noise and stabilize the power rail. * **NTC Thermistor:** An optional external resistor to monitor battery or coil temperature. --- ### 4. Communication Block (I2C) The P9222-R uses an I2C interface to communicate with the host processor. This allows the system to: * Read telemetry data (current, voltage, temperature). * Change the output voltage dynamically. * Monitor charging status and error codes. ---