# Ci522

**Nanjing Zhongke Microelectronics** · RFID ICs · QFN-16-EP(3x3)

Ci522 from Nanjing Zhongke Microelectronics, in a QFN-16-EP(3x3). Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VDD1 | power_in | Pad power supply |
| 2 | NRSTPD | input | Reset and power-down input: enabled by a positive edge to reset, or enabled when LOW for power-down with internal current sinks switched off, oscillator inhibited, and input pins disconnected from the outside world |
| 3 | VDD2 | power_in | Floating power supply pin |
| 4 | TX1 | output | Transmitter 1 delivers the modulated 13.56 MHz energy carrier |
| 5 | VDD3 | power_in | Transmitter power supply: supplies the output stage of transmitters 1 and 2 |
| 6 | TX2 | output | Transmitter 2 delivers the modulated 13.56 MHz energy carrier |
| 7 | VDD4 | power_in | Analog power supply |
| 8 | VMID | power_in | Internal reference voltage |
| 9 | RX | input | RF signal input |
| 10 | OSCIN | input | Crystal oscillator inverting amplifier input; also accepts externally generated clock input at fclk = 27.12 MHz |
| 11 | OSCOUT | output | Crystal oscillator inverting amplifier output |
| 12 | MISO | output | SPI master in, slave out |
| 13 | MOSI | input | SPI master out, slave in |
| 14 | SCK | input | SPI serial clock input |
| 15 | NSS | input | SPI chip select input |
| 16 | IRQ | output | Interrupt request output: indicates an interrupt event and can be configured as open-drain or push-pull |
| 17 | VSS | power_in | Ground: connection of heatsink pad on package underside |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Nanjing Zhongke Microelectronics |
| Package | QFN-16-EP(3x3) |
| Category | RF And Wireless |
| Pins | 17 |

## CAD (KiCad official)

- Symbol: `Ci522`
- Footprint: `Package_DFN_QFN:QFN-16-1EP_3x3mm_P0.5mm_EP1.7x1.7mm`
- 3D model: QFN-16-EP(3x3) (KiCad packages3D, STEP)
- 3D model files: `ci522-etched.step` / `ci522-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ci522.step` / `ci522.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Nanjing Zhongke Microelectronics datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588906588485144577) (50 pp, sha256 `b4ca45fff0896a1a`, retrieved 2026-09-18, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.2`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-4-6` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/ci522-datasheet.pdf)