EM4123- EPC and UHF ICs

Read-only, TTO RFID IC

General Description

The chip is used in passive UHF read-only transponder applications. It is powered up by an RF beam transmitted by the reader, which is received and rectified to generate a supply voltage for the chip. A pre-programmed code is transmitted to the reader by varying the amount of energy that is reflected back to the reader. It implements a robust and fast anti-collision protocol.

The EM4123 is frequency independent and can be used for RF coupled applications where reading ranges in excess of 10 m and reading rates of 120 tags per second at 256 kbit/s can be attained. The circuit is backscattering data using load modulation. Therefore the reader should be able to detect ASK and PSK modulated carrier.


  • Anti-collision suited for fast moving objects
  • Very low current consumption, long range solution
  • Easy to use, only pure CW RFID reader needed (No dense reader mode issue)
  • Protocol and coding backward compatible with EM4122 and EM4222
  • Low cost solutions

The chip is ideal for applications where long range, high-speed item identification is required:

  • Supply chain management
  • Tracking and tracing
  • Access control
  • Asset control
  • Licensing
  • Auto-tolling
  • Animal tagging
  • Sports event timing

Order now


  • Factory programmed 64 bit ID number
  • High data rate: Up to 256 kbit/s
  • Frequency independent: Typically used at 869 MHz, 902 - 960 MHz (versions 001 to 099)
  • On-chip oscillator
  • On-chip rectifier
  • Low voltage operation - down to 1.0 V at ambient temperature
  • Tag Talk Only protocol (TTO)
  • Low power consumption
  • -40┬░ to +85┬░ C operating temperature
EM4123 Fact Sheet41.28 KB
EM4123 Data Sheet343.15 KB