Description
The EM4022 (previously named P4022) chip implements patented anti-collision protocols for both high frequency and low frequency applications. It is even possible to identify transponders with identical codes, thereby making it possible to count identical items. The chip is typically used in “passive” transponder applications, i.e. it does not require a battery power source. Instead, it is powered up by an electromagnetic energy field or beam transmitted by the reader, which is received and rectified to generate a supply voltage for the chip. A preprogrammed code is transmitted to the reader by varying the amount of energy that is reflected back to the reader. This is done by modulating an antenna or coil, thereby effectively varying the load seen by the reader.

Features
■ Implements all BTG anti-collision protocols: Fast SWITCH-OFF, SLOW-DOWN, and FREE-RUNNING
■ Can be used to implement low frequency inductive coupled transponders, high frequency RF coupled transponders or bi-frequency transponders
■ Reading 500 transponders in less than one second for high frequency applications
■ Factory programmed 64 bit ID number
■ Data rate options form 4 kbit/s to 64 kbit/s
■ Manchester data encoding
■ Any field frequency: Typically 125 kHz, 13.56 MHz inductive and 100 MHz to 2.54 GHz RF
■ Data transmission done by amplitude modulation
■ Trimmed 110 pF ± 3% on-chip resonant capacitor
■ On-chip oscillator, rectifier and voltage limiter
■ Low power consumption
■ Low voltage operation : down to 1.5 V at ambient temperature
■ -40 to +85 °C operating temperature range

Typical Applications
■ Access control
■ Animal tagging
■ Asset control
■ Sports event timing
■ Licensing
■ Electronic keys
■ Auto-tolling