CD74HC191EE4

同步向上/向下计数器， DOWN / UP模式控制 SYNCHRONOUS UP/DOWN COUNTERS WITH DOWN/UP MODE CONTROL

description/ordering information

The CD54/74HC190 are asynchronously presettable BCD decade counters, whereas the CD54/74HC191 and CD54/74HCT191 are asynchronously presettable binary counters.

• 2-V to 6-V VCC Operation ’HC190, 191

• 4.5-V to 5.5-V VCC Operation ’HCT191

• Wide Operating Temperature Range of −55°C to 125°C

• Synchronous Counting and Asynchronous Loading

• Two Outputs for n-Bit Cascading

• Look-Ahead Carry for High-Speed Counting

• Balanced Propagation Delays and Transition Times

• Standard Outputs Drive Up To 15 LS-TTL Loads

• Significant Power Reduction Compared to LS-TTL Logic ICs