The PT2221 and PT2222 are remote control transmitters utilizing CMOS Technology specially designed for use on infrared remote control applications. They are pin-to-pin compatible with NEC PD6121 and PD6122 respectively. PT2221 is packaged in 20 pins SO and capable of controlling 32 functions and 3 double keys. PT2222, on the other hand, is housed in 24 pins SO and capable of controlling 64 function keys and 3 double keys. PT2221/2 may be paired with PT2225 to construct a powerful remote control system.