Counter IC Binary Counter 1 Element 4 Bit Positive Edge 16-DIP
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
description/ordering information The ’HC191 devices are 4-bit synchronous, reversible, up/down binary counters. Synchronous counting operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when instructed by the steering logic. This mode of operation eliminates the output counting spikes normally associated with asynchronous (ripple-clock) counters. ● Wide Operating Voltage Range of 2 V to 6 V ● Outputs Can Drive Up To 10 LSTTL Loads ● Low Power Consumption, 80-µA Max ICC ● Typical tpd = 13 ns ● ±4-mA Output Drive at 5 V ● Low Input Current of 1 µA Max ● Single Down/Up Count-Control Line ● Look-Ahead Circuitry Enhances Speed of Cascaded Counters ● Fully Synchronous in Count Modes ● Asynchronously Presettable With Load Control