NFC System Design & Prototype

# NFC Design Requirements ## 1. Basic Requirements * **NFC Frequency:** 13.56 MHz * **NFC IC Supply:** 3.3 V * **NFC IC:** NXP NFC IC * **Host MCU:** ESP32 / selected MCU * **Communication:** I²C * **Antenna:** PCB loop antenna * **Target NFC Range:** 20–30 mm * **PCB:** 2-layer PCB preferred * **Operating Temperature:** -20°C to +70°C ## 2. NFC Antenna * PCB antenna shall be designed for **13.56 MHz**. * Antenna dimensions shall be optimized based on available PCB space. * Keep ground copper away from the antenna area. * Keep battery and other metal objects away from the antenna where possible. * Antenna matching components shall be provided for tuning. ## 3. Power * NFC IC supply: **3.3 V** * Provide local decoupling capacitors near the NFC IC. * NFC supply shall be stable during NFC transmission. ## 4. PCB Layout * Keep NFC IC and matching network close together. * Keep RF traces short. * Keep switching regulators and high-speed digital signals away from the antenna/RF section. * Provide test points for **3.3 V, GND, I²C and RESET/IRQ**. ## 5. Functional Requirements The NFC shall: * Detect compatible NFC devices. * Read/write required NFC data. * Communicate reliably with smartphones. * Operate reliably at different phone orientations. * Maintain the required NFC range. ## 6. Testing The prototype shall be tested for: * 13.56 MHz antenna resonance * Antenna tuning * NFC communication * NFC operating range * Different smartphones * Power consumption * Final enclosure effect on NFC performance ## 7. Design Deliverables * NFC schematic * PCB layout * NFC antenna * BOM * NFC firmware * Antenna tuning results * Functional test results