'290, 'LS290...DECADE COUNTERS
'293, 'LS293...4–BIT BINARY COUNTERS
The SN54290/SN74290, SN54LS290/SN74LS290, SN54293/SN74293, and SN54LS293/SN74LS293 counters are electrically and functionally identical to the SN5490A/SN7490A, SN54LS90/SN74LS90, SN5493A/SN7493A, and SN54LS93/SN74LS93, respectively. Only the arrangement of the terminals has been changed for the '290, 'LS290, '293, and 'LS293.
Each of these monolithic counters contains four master-slave flip-flops and additional gating to provide a divide-by-two counter and a three-stage binary counter for which the count cycle length is divide-by-five for the '290 and 'LS290 and divide-by-eight for the '293 and 'LS293.
All of these counters have a gated zero reset and the '290 and 'LS290 also have gated set-to-nine inputs for use in BCD nine's complement applications.
To use the maximum count length (decade or four-bit binary) of these counters, the B input is connected to the QA output. The input count pulses are applied to input A and the outputs are as described in the appropriate function table. A symmetrical divide-by-ten count can be obtained from the '290 and 'LS290 counters by connecting the QD output to the A input and applying the input count to the B input which gives a divide-by-ten square wave at output QA.
| Top documentation | Type | Title | Format options | Date |
|---|---|---|---|---|
| * | Data sheet | Decade And 4-Bit Binary Counters datasheet | 01 Mar 1988 |
Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.
If you have questions about quality, packaging or ordering TI products, see TI support.