SN74HC193N

The SN74HC193N is a 4-bit Synchronous Up/Down Counter (dual clock with clear), operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincidentally with each other when so instructed by the steering logic. This mode of operation eliminates the output counting spikes normally associated with asynchronous (ripple-clock) counters. The outputs of the four flip-flops are triggered on a low-to-high-level transition of either count input. The direction of counting is determined by which count input is pulsed while the other count input is high. All four counters are fully programmable, that is, each output may be preset to either level by placing a low on the LOAD\ input and entering the desired data at the data inputs. The output changes to agree with the data inputs independently of the count pulses. This feature allows the counters to be used as modulo-N dividers simply by modifying the count length with the preset inputs.

• Outputs can drive up to 10 LSTTL loads
• 20ns Typical tpd
• Look-ahead circuitry enhances cascaded counters
• Fully synchronous in count modes
• Parallel asynchronous load for modulo-n count lengths
• Asynchronous clear
• 80µA Maximum low power consumption
• ±4mA Output drive at 5V
• 1µA Maximum low input current