Decade and Binary Counters
DM74LS90 DM74LS93 Decade and Binary Counters
June 1989
DM74LS90 DM74LS93 Decade and Binary Counters
General Descripti...
Description
DM74LS90 DM74LS93 Decade and Binary Counters
June 1989
DM74LS90 DM74LS93 Decade and Binary Counters
General Description
Each of these monolithic counters contains four masterslave flip-flops and additional gating to provide a divide-bytwo counter and a three-stage binary counter for which the count cycle length is divide-by-five for the ’LS90 and divideby-eight for the ’LS93
All of these counters have a gated zero reset and the LS90 also has gated set-to-nine inputs for use in BCD nine’s complement applications
To use their maximum count length (decade or four bit binary) 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 truth table A symmetrical divide-by-ten count can be obtained from the ’LS90 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
Features
Y Typical power dissipation 45 mW Y Count frequency 42 MHz
Connection Diagrams (Dual-In-Line Packages)
TL F 6381 – 1
Order Number DM74LS90M or DM74LS90N See NS Package Number M14A or N14A
TL F 6381 – 2
Order Number DM74LS93M or DM74LS93N See NS Package Number M14A or N14A
C1995 National Semiconductor Corporation TL F 6381
RRD-B30M105 Printed in U S A
Absolute Maximum Ratings (Note)
If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specific...
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