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Technical Specifications
Parameters and characteristics for this part
| Specification | CD74HC191EG4 |
|---|---|
| Count Rate | 35 MHz |
| Direction | Up, Down |
| Logic Type | Binary Counter |
| Mounting Type | Through Hole |
| Number of Bits per Element | 4 |
| Number of Elements | 1 |
| Operating Temperature [Max] | 125 °C |
| Operating Temperature [Min] | -55 °C |
| Package / Case | 0.3 in |
| Package / Case | 16-DIP |
| Package / Case | 7.62 mm |
| Reset | Asynchronous |
| Supplier Device Package | 16-PDIP |
| Timing | Synchronous |
| Trigger Type | Positive Edge |
| Voltage - Supply [Max] | 6 V |
| Voltage - Supply [Min] | 2 V |
Pricing
Prices provided here are for design reference only. For realtime values and availability, please visit the distributors directly
| Distributor | Package | Quantity | $ | |
|---|---|---|---|---|
| Digikey | Tube | 1025 | $ 0.40 | |
Description
General part information
SN74HC191 Series
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.
The outputs of the four flip-flops are triggered on a low- to high-level transition of the clock (CLK) input if the count-enable (CTEN)\ input is low. A high at CTEN\ inhibits counting. The direction of the count is determined by the level of the down/up (D/U\) input. When D/U\ is low, the counter counts up, and when D/U\ is high, it counts down.
These counters feature a fully independent clock circuit. Change at the control (CTEN\ and D/U\) inputs that modifies the operating mode have no effect on the contents of the counter until clocking occurs. The function of the counter is dictated solely by the condition meeting the stable setup and hold times.
Documents
Technical documentation and resources
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