MC14419

MCl~19 2-OF-8 KEYPAD-TO-BINARY ENCODER The MC14419 is designed for phone dialer system applications, but finds many applications as a keypad-to-binary encoder. The device con- tains a 2-of-8 to binary encoder, a strobe generator, and an illegal state detector. The encoder has four row inputs and four column inputs, and is designed to accept inputs from 16 keyswitches arranged in a 4x 4 matrix. For an output on the four data lines, one and only one row along with one and only one column input line must be activated. All other combinations are suppressed by the illegal state detector to eliminate false data output. The strobe generator produces a strobe pulse when any of the 10 keys corresponding to numerals O through 9 are depressed. The strobe output can be used to eliminate erroneous data entry due to contact bounce. For a strobe output to occur, the key row and column input lines must remain stable for 80 clock pulses after activation. When the *,,}tt contact bounce ...