### Technical Overview: P9025AC-RNBGI8 The **P9025AC-RNBGI8** is a highly integrated, single-chip wireless power receiver developed by Renesas (formerly IDT). It is specifically designed for mobile applications that require compliance with the WPC (Wireless Power Consortium) Qi standard. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Type** | Wireless Power Receiver IC | | **Standard Compliance** | WPC 1.1.2 (Qi Standard) | | **Output Power** | Up to 5W | | **Efficiency** | > 80% (System Level) | | **Communication** | I2C Interface | | **Package** | VFQFPN-32 (5x5 mm) | | **Protection** | Thermal, Voltage, and Current limits | --- ### 2. Internal Electronic Architecture The device integrates several critical functional blocks that traditionally required separate components: * **Full-Bridge Synchronous Rectifier:** Converts the AC induced current from the receiver coil into a stable DC voltage with high efficiency. * **Integrated LDO Regulator:** A low-dropout regulator provides a regulated 5V output to the mobile system (battery charger or PMIC). * **Microcontroller (MCU):** An embedded core handles the Qi communication protocol, including the "Ping," "Identification," and "Power Transfer" phases. * **Modulation Circuitry:** Uses back-scatter modulation (capacitive or resistive) to send data packets back to the transmitter (TX). * **FOD (Foreign Object Detection):** Sophisticated circuitry that monitors power loss to detect metal objects between the TX and RX, preventing overheating. --- ### 3. Application Circuit Components When designing with the P9025AC, several peripheral electronic parts are required: 1. **Rx Coil:** Typically a flat copper spiral inductor that receives the electromagnetic field. 2. **Resonant Capacitors:** High-precision capacitors (C1, C2) used to tune the LC circuit to the 100-205 kHz Qi frequency. 3. **Communication Capacitors:** Smaller capacitors used to toggle the impedance for data transmission. 4. **NTC Thermistor:** An external temperature sensor to monitor the battery or coil temperature for safety. --- ### 4. Pins and Connectivity * **AC1 / AC2:** Connections for the wireless power receiver coil. * **OUT:** The regulated DC output pin (5V). * **SCL / SDA:** I2C clock and data lines for communication with the host processor. * **FOD:** Programming pin to calibrate Foreign Object Detection thresholds. ---