Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

SN74LS90 Datasheet(PDF) 3 Page - ON Semiconductor

Part No. SN74LS90
Description  4-BIT BINARY COUNTER
Download  7 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  ONSEMI [ON Semiconductor]
Homepage  http://www.onsemi.com
Logo ONSEMI - ON Semiconductor

SN74LS90 Datasheet(HTML) 3 Page - ON Semiconductor

  SN74LS90 Datasheet HTML 1Page - ON Semiconductor SN74LS90 Datasheet HTML 2Page - ON Semiconductor SN74LS90 Datasheet HTML 3Page - ON Semiconductor SN74LS90 Datasheet HTML 4Page - ON Semiconductor SN74LS90 Datasheet HTML 5Page - ON Semiconductor SN74LS90 Datasheet HTML 6Page - ON Semiconductor SN74LS90 Datasheet HTML 7Page - ON Semiconductor  
Zoom Inzoom in Zoom Outzoom out
 3 / 7 page
background image
SN74LS90
http://onsemi.com
3
FUNCTIONAL DESCRIPTION
The LS90, LS92, and LS93 are 4-bit ripple type Decade,
Divide-By-Twelve, and Binary Counters respectively. Each
device consists of four master/slave flip-flops which are
internally connected to provide a divide-by-two section and a
divide-by-five
(LS90),
divide-by-six
(LS92),
or
divide-by-eight (LS93) section. Each section has a separate
clock input which initiates state changes of the counter on the
HIGH-to-LOW clock transition. State changes of the Q
outputs do not occur simultaneously because of internal
ripple delays. Therefore, decoded output signals are subject
to decoding spikes and should not be used for clocks or
strobes. The Q0 output of each device is designed and
specified to drive the rated fan-out plus the CP1 input of the
device.
A gated AND asynchronous Master Reset (MR1 • MR2) is
provided on all counters which overrides and clocks and
resets (clears) all the flip-flops. A gated AND asynchronous
Master Set (MS1 • MS2) is provided on the LS90 which
overrides the clocks and the MR inputs and sets the outputs
to nine (HLLH).
Since the output from the divide-by-two section is not
internally connected to the succeeding stages, the devices
may be operated in various counting modes.
LS90
A. BCD Decade (8421) Counter — The CP1 input must be
externally connected to the Q0 output. The CP0 input
receives the incoming count and a BCD count sequence
is produced.
B. Symmetrical Bi-quinary Divide-By-Ten Counter — The Q3
output must be externally connected to the CP0 input. The
input count is then applied to the CP1 input and a
divide-by-ten square wave is obtained at output Q0.
C. Divide-By-Two and Divide-By-Five Counter — No
external interconnections are required. The first flip-flop is
used as a binary element for the divide-by-two function
(CP0 as the input and Q0 as the output). The CP1 input is
used to obtain binary divide-by-five operation at the Q3
output.
LS92
A. Modulo 12, Divide-By-Twelve Counter — The CP1 input
must be externally connected to the Q0 output. The CP0
input receives the incoming count and Q3 produces a
symmetrical divide-by-twelve square wave output.
B. Divide-By-Two and Divide-By-Six Counter —No external
interconnections are required. The first flip-flop is used as
a binary element for the divide-by-two function. The CP1
input is used to obtain divide-by-three operation at the Q1
and Q2 outputs and divide-by-six operation at the Q3
output.
LS93
A. 4-Bit Ripple Counter — The output Q0 must be externally
connected to input CP1. The input count pulses are
applied to input CP0. Simultaneous divisions of 2, 4, 8,
and 16 are performed at the Q0, Q1, Q2, and Q3 outputs as
shown in the truth table.
B. 3-Bit Ripple Counter— The input count pulses are applied
to input CP1. Simultaneous frequency divisions of 2, 4,
and 8 are available at the Q1, Q2, and Q3 outputs.
Independent use of the first flip-flop is available if the reset
function coincides with reset of the 3-bit ripple-through
counter.


Html Pages

1  2  3  4  5  6  7 


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn