EM EM4425 NFC Chip

(EM4425V10, EM4425V12)

The EM4425 is a dual tag technology chip from EM Microelectronic that has both NFC and UHF RFID chip functionality. The single integrated circuit is connected to two antennas; tuned for each technology’s frequency. The chip comes in several models (V10..V16), but the V10 and V12 are the most common and support the dual NFC/UHF RFID features.

dual nfc uhf rid chip tag


The EM4425 is a sophisticated chip with many NFC chip features and UHF RFID chip features. The EM4425 comes in several versions (V10..V12) which have different features and configurations; see the technical specification for the specific details. The EM4425V12 comes from the manufacturer in an uninitialized state, and must be initialized before any usage to configure the chip features to the user’s needs. The EM4425V10 is initialized by the manufacturer in a state optimized for NFC consumer engagement (mobile apps reading NDEF) and standard usage of UHF RFID.

Specialized software must be used to perform the initialization process of the EM4425 chip; not event EM’s own mobile apps or the NXP NFC TagInfo app work correctly with an uninitialized tag. Therefore it is recommended to use the EM4425V10 so that the initialization step does not need to be performed, unless there is a very specific use case requiring custom configuration.

Serial Number

A standard NFC chip has a UID and a UHF RFID chip has a TID to uniquely identify the chip. Both the UID and TID conform to various standards and are of different lengths. In the EM4425 chip, part of the UID and part of the TID have the same value; called the chip’s serial number. The serial number is a 6 byte (48 bit) value; see the technical specification for more information. The benefit of this shared serial number is the two tag technologies can be correlated in a data store with this single identifier.