GND and Vcc on Corner Pins

(Pins 7 and 14 Respectively)

description

The SN54290/SN74290, SNS4LS290/SN74LS290,

SN54293/SN74293, and SNSALS293/SN74LS293

counters are electrically and functionally identical to

the SNS490A/SN7490A, SNSALSIO/SN74LSI0,

SN5493A/SN7493A, and SNSALSO3/SN74LSE3,

respectively. Only the arrangement of the terminals

has been changed for the 290, 'LS290, ‘293, and

‘15293.

Each of these monolithic counters contains four

master-slave flip-flops and additional gating to pro-

Vide 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 of four-bit

binary) of these counters, the B input is connected to

the Q 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 p output to the A input

and applying the input count to the 8 input which

gives a divide-by-ten square wave at output QA.