145026P

MOTOROLA SEMICONDUCTOR TECHNICAL DATA Order this document by MC145026/D Encoder and Decoder Pairs CMOS These devices are designed to be used as encoder/decoder pairs in remote control applications. The MC145026 encodes nine lines of information and serially sends this information upon receipt of a transmit enable (TE) signal. The nine lines may be encoded with trinary data (low, high, or open) or binary data (low or high). The words are transmitted twice per encoding sequence to increase security. The MC145027 decoder receives the serial stream and interprets five of the trinary digits as an address code. Thus, 243 addresses are possible. If binary data is used at the encoder, 32 addresses are possible. The remaining serial information is interpreted as four bits of binary data. The valid transmission (VT) output goes high on the MC145027 when two conditions are met. First, two addresses must be consecutively received (in one encoding sequence) which both match the local address. Second, the 4 bits of data must match the last valid data received. The active VT indicates that the information at the Data output pins has been updated. The MC145028 decoder treats all nine trinary digits as an address which allows 19,683 codes. If binary data is encoded, 512 codes are possible. The VT output goes high on the MC145028 when two addresses are consecutively received (in one encoding sequence) which both match the local address. Operating Temperature Range: – 40 to + 85°C Very–Lo...