74LS299 8-bit Universal Shift/Storage Register


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. 74LS299 Schottky TTL eight-bit universal registers feature multiplexed inputs/outputs to achieve full eight-bit data handling in a single 20-pin package. Two function-select inputs and two output-control inputs can be used to choose the modes of operation listed in the function table

74LS299 Features

  • Multiplexed Input/Outputs for Data Hold, Shift Right, Shift Left and Load Data
  • Operates with Outputs Enabled or at High Z
  • 3-State Outputs Drive Bus Lines Directly
  • Can be Cascaded for N-Bit Word Lengths
  • Standard TTL Switching Voltages

74LS299 Specifications

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

74LS299 Pinout Diagram

74LS299 Pin Description

Pin NoPin NameDescription
1S0Select Pin 0
2OE1Enable Output Pin 1
3OE2Enable Output Pin 2
4I/O6Input/Output Pin 6
5I/O4Input/Output Pin 4
6I/O2Input/Output Pin 2
7I/O0Input/Output Pin 0
8Q0Output Pin
9MRAsynchronous Master Reset Pin
11DS0Digital signal Pin 0
12CPClock Pulse
13I/O1Input/Output Pin 1
14I/O3Input/Output Pin 3
15I/O5Input/Output Pin 5
16I/O7Input/Output Pin 7
17Q7Output Pin
18DS7Digital signal Pin 7
19S1Select Pin 1
20VCCPositive Supply


  • Storing data in digital form.

74LS299 Alternative Equivalent

Download the 74LS299 8-bit Universal Shift/Storage Register Datasheet from the link given below.