REI Datasheet
SN5490A, ‘92A, ‘93A, SN54LS90, ‘LS92, ’LS93
SN7490A, ‘92A, ‘93A, SN74LS90, ‘LS92, ’LS93
Decade, Divide-By-Twelve And Binary Counters
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-six for the ‘92A and ‘LS92, and the divide-by-eight for the ‘93A and ‘LS93. All of these
counters have a gated zero reset and the ‘90A and ‘LS90 also have gated set-to-nine inputs for use
in BCD nine’s complement applications.
To use their maximum count length (decade, divide-by-twelve, or four-bit binary) of these counters,
the CKB input is connected to the QA output. The input count pulses are applied to CKA input and the
outputs are as described in the appropriate function table. A symmetrical divide-by-ten count can be
obtained from the ‘90A or ‘LS90 counters by connecting the QD output to the CKA input and applying
the input count to the CKB input which gives a divide-by-ten square wave at output QA.
Rochester Electronics
Manufactured Components
Rochester branded components are
manufactured using either die/wafers
purchased from the original suppliers
or Rochester wafers recreated from the
original IP. All recreations are done with
the approval of the OCM.
Parts are tested using original factory
test programs or Rochester developed
test solutions to guarantee product
meets or exceeds the OCM data sheet.
Quality Overview
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•
•
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ISO-9001
AS9120 certification
Qualified Manufacturers List (QML) MIL-PRF-38535
• Class Q Military
• Class V Space Level
Qualified Suppliers List of Distributors (QSLD)
• Rochester is a critical supplier to DLA and
meets all industry and DLA standards.
Rochester Electronics, LLC is committed to supplying
products that satisfy customer expectations for
quality and are equal to those originally supplied by
industry manufacturers.
The original manufacturer’s datasheet accompanying this document reflects the performance
and specifications of the Rochester manufactured version of this device. Rochester Electronics
guarantees the performance of its semiconductor products to the original OEM specifications.
‘Typical’ values are for reference purposes only. Certain minimum or maximum ratings may be
based on product characterization, design, simulation, or sample testing.
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