74LS125 Quad Bus Buffer Negative Enable Tri-State


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. 74LS125 bus buffers feature three-state outputs that, when enabled, have the low impedance characteristics of a TTL output with additional drive capability at high logic levels to permit driving heavily loaded bus lines without external pullup resistors.

74LS125 Features

  • Four Independent Non-Inverting Buffer Gates
  • Enabled Mode
  • Fast Switching Times
  • Operating Temperature up to 70°C
  • Standard TTL Switching Voltages

74LS125 Specifications

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

74LS125 Pinout Diagram

74LS125 Pin Description

Pin NoPin NameDescription
1E’Invert Enable Pin Of Buffer 1
2DData Input Of Buffer 1
3OOutput Of Buffer 1
4E’Invert Enable Pin Of Buffer 2
5DData Input Of Buffer 2
6OOutput Of Buffer 2
8OOutput Of Buffer 3
9DData Input Of Buffer 3
10E’Invert Enable Pin Of Buffer 3
11OOutput Of Buffer 4
12DData Input Of Buffer 4
13E’Invert Enable Pin Of Buffer 4
14VCCPositive Supply

74LS125 Circuit


  • A buffer or a voltage buffer is used to isolate input from the output. The buffer’s output state mirrors the input state.

74LS125 Alternative Equivalent


Download 74LS125 Quad Bus Buffer Negative Enable Tri-State Datasheet from the link given below.