74LS161 Synch 4-bit Counter

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The 74LS series of integrated circuits (ICs) was one of the most popular logic families of transistor-transistor logic (TTL) logic chips. 74LS series is a bipolar, low-power Schottky IC.74LS161 synchronous, presettable counters feature an internal carry look-ahead for application in high-speed counting designs. The 161 is a 4-bit binary counter. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when structured by the count-enable inputs and internal gating.

74LS161 Features

  • Edge Triggered High-Speed 4-bit Synchronous (Binary) Counters
  • Asynchronous Master Reset
  • Count Rate of 35MHz
  • Operating Temperature up to 70°C
  • Standard TTL Switching Voltages

74LS161 Specifications

Supply Voltage4.75 – 5.25Vdc
Maximum Clock Frequency40Mhz
Power Dissipation2mW/gate @100kHz
Minimum Output Current8mA
Propagation Delay10nS
Fan Out (TTL Loads)20

74LS161 Pinout Diagram

74LS161 Pin Description

Pin NoPin NameDescription
1CLR’Clear Pin
2CLKClock Pin
3AData Input Of Counter A
4BData Input Of Counter B
5CData Input Of Counter C
6DData Input Of Counter D
7ENPEnable Pin
8GNDGround
9LOAD’Load Pin
10ENTEnable Pin T
11QDOutput Of Counter QD
12QCOutput Of Counter QC
13QBOutput Of Counter QB
14QAOutput Of Counter QA
15RCORipple Carry Output
16VCCPositive Supply

Applications

  • Frequency counters
  • Digital clocks
  • Analog to digital converters
  • With some changes in their design, counters can be used as frequency divider circuits
  • In time measurement

74LS161 Alternative Equivalent

74LS163

Download 74LS161 Synch 4-bit Counter Datasheet from the link given below.