74LS169 Synchronous Binary Up/Down Counter


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. The 74LS169 is a fully synchronous 4-stage up/down counter featuring a preset capability for programmable operation, carry lookahead for easy cascading, and a U/D input to control the direction of counting

74LS169 Features

  • Programmable Look-Ahead Up/Down Binary Counter
  • Fully Synchronous Operation
  • Internal Look-Ahead
  • Carry Output for Cascading
  • Standard TTL Switching Voltages

74LS169 Specifications

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

74LS169 Pinout Diagram

74LS169 Pin Description

Pin NoPin NameDescription
1U/D’Up/Down (Active Low Pin)
2CLKClock Pin
3AData Input Of Counter A
4BData Input Of Counter B
5CData Input Of Counter C
6DData Input Of Counter D
7ENP’Enable Pin Parallel (Active Low)
8GNDGround Pin
9LOAD’Load Pin
10ENT’Enable Pin Trinkle (Active Low)
11QDCounter Output QD
12QCCounter Output QC
13QBCounter Output QB
14QACounter Output QA
15RCORipple Carry Output
16VCCPositive Supply


  • Self-reversing counter
  • Clock divider circuit

74LS169 Alternative Equivalent


Download 74LS169 Synchronous Binary Up/Down Counter Datasheet from the link given below.