# RFID 125kHz Technology: A Comprehensive Guide ## What is RFID 125kHz? **RFID 125kHz** systems operate in the low-frequency (LF) band and are one of the most established and widely used RFID technologies globally. I personally recall my first encounter with this technology years ago when implementing a simple access control system for a small office. The reliability and simplicity of the 125kHz tags, even in that basic project, left a lasting impression on me about the robustness of LF RFID. ### Core Technical Specifications & Parameters For engineers and integrators, understanding the precise technical metrics is crucial. Below are detailed specifications for a typical **RFID 125kHz** reader module and tag set. *Please note: These technical parameters are for reference data. For exact specifications, you must contact the backend management team.* **Reader Module (Example Model: TIANJUN-LF-101A):** * **Operating Frequency:** 125 kHz ± 5 kHz * **Communication Interface:** UART (TTL level), Wiegand 26/34, RS-232 * **Operating Voltage:** 5V DC / 12V DC * **Read Range:** 5 - 10 cm (dependent on coil size and tag) * **Supported Protocols:** EM4100, EM4102, TK4100 * **Chipset Code:** Based on Atmel ATmega8L microcontroller (or equivalent proprietary ASIC) * **Antenna:** Integrated or external, typical inductance of 1.2mH. * **Dimensions (PCB):** 40mm x 60mm x 15mm **Passive Keyfob Tag (Example Model: TIANJUN-TAG-125K):** * **Chip:** EM4100 compatible wafer * **Memory:** 64-bit Read-Only (ROM) * **Data Format:** 40-bit Unique ID + 24-bit parity/header * **Operating Frequency:** 125 kHz * **Material:** ABS plastic or PVC * **Dimensions:** 30mm x 50mm x 6mm (Standard Keyfob) * **Weight:** 10 grams --- ## My Experience and Perspective on 125kHz RFID In my professional opinion, while UHF RFID gets more attention for supply chain logistics, the **RFID 125kHz** standard holds an irreplaceable position. Its primary strength is excellent performance near metals and liquids, where higher frequencies struggle. A natural skill I've developed is quickly designing antenna coils for custom **RFID 125kHz** applications, which is more art than science, requiring careful calculation and empirical testing. ### Entertainment & Creative Application Cases Beyond security, **RFID 125kHz** tags enable fun, interactive experiences. I once helped a local escape room create a "magic wand" system. Players used wands embedded with **RFID 125kHz** tags to trigger hid