Fairchild

Description

/100 seconds to years. The counters are controlled by a pulse train divided down from a crystal oscillator circuit, and the frequency of the crystal is selectable 3 Description. Supports 1-MHz Fast Mode Plus I2C Bus. The TCA8418E is a keypad scan device with integrated ESD protection. It can operate from 1.65 V. Features. 16 Key Pushbutton Pad in 4 x 4 Matrix. Four Digit Multiplexed LED Display with Flashing Colon. Industrial Real Time Clock/Timer. Controls to control the decoded address lines and a 74LS139 decoder driven from the least significant address bits provides the active-low CS1 through CS4 signals. by a 74LS139 dual 1-of-4 demultiplexer. The state of inputs. 1A and 1B determines which channel is selected, and the state of inputs 2A and 2B determines