SN54HC191, SN74HC191 4ĆBIT SYNCHRONOUS UP/DOWN BI.
Texas Instruments
SN74HC191N - 4-BIT SYNCHRONOUS UP/DOWN BINARY COUNTERS
SN54HC191, SN74HC191 4ĆBIT SYNCHRONOUS UP/DOWN BINARY COUNTERS D Wide Operating Voltage Range of 2 V to 6 V D Outputs Can Drive Up To 10 LSTTL Loads .