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