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 contains 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.

● Suppressed Output for Illegal Input Code
● On-Chip Pullup Resistors for Row and Column Inputs
● Clock Input Conditioning Circuit
● Low Current Drain in Standby Mode
   5.0μA Typical @ 5.0 Vdc
● Subsystem Complement to the MC14408/14409 Phone Pulse Converter
● Codes for Numbers 0-9 Produce a Strobe Pulse
● One Key Rollover Feature