UT54ACS191
UT54ACS191 is Synchronous 4-Bit Up-Down Binary Counters manufactured by Aeroflex Circuit Technology.
FEATURES
Single down/up count control line Look-ahead circuitry enhances speed of cascaded counters Fully synchronous in count modes Asynchronously presettable with load control 1.2μ CMOS
- Latchup immune High speed Low power consumption Single 5 volt supply Available QML Q or V processes Flexible package
- 16-pin DIP
- 16-lead flatpack UT54ACS191
- SMD 5962-96564 UT54ACTS191
- SMD 5962-96565
DESCRIPTION
The UT54ACS191 and the UT54ACTS191 are synchronous 4bit 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 so instructed. Synchronous operation eliminates the output counting spikes associated with asynchronous counters.
The outputs of the four flip-flops are triggered on a low-to-highlevel transition of the clock input if the enable input (CTEN) is low. A logic one applied to 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.
The counters feature a fully independent clock circuit. Changes at control inputs (CTEN and D/U) that will modify the operating mode have no effect on the contents of the counter until clocking occurs.
The counters are fully programmable. The outputs may be preset to either logic level by placing a low on the load input and entering the desired data at the data inputs. The output will change to agree with the data inputs independently of the level of the clock input. The asynchronous load allows counters to be used as modulo-N dividers by simply modifying the count length with the preset inputs.
Two outputs have been made available to perform the cascading function: ripple clock and maximum/minimum (MAX/MIN) count. The MAX/MIN output produces a high-level output pulse with a duration approximately equal to one plete cycle of the clock while the count is...
