74LS27 Triple 3-input NOR Gate


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. 74LS27 Triple 3-input NOR Gate contains three independent 3-input NOR gates.

74LS27 Features

  • Three Independent NOR Gates
  • Standard Pin Configuration
  • Fast Switching Times
  • Operating Temperature up to 70°C
  • Standard TTL Switching Voltages

74LS27 Specifications

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

74LS27 Pinout Diagram

74LS27 Pin Description

Pin NoPin NameDescription
1A1NOR Gate 1 Input 1
2B1 NOR Gate 1 Input 2
3A2 NOR Gate 2 Input 1
4B2 NOR Gate 2 Input 2
5C2 NOR Gate 2 Input 3
6D2 NOR Gate 2 Output
8D3 NOR Gate 3 Output
9A3 NOR Gate 3 Input 1
10B3 NOR Gate 3 Input 2
11C3 NOR Gate 3 Input 3
12D1 NOR Gate 1 Output
13C1 NOR Gate 1 Input 3
14VCCPositive Supply

74LS27 Circuit


  • Mixer tank

74LS27 Alternative Equivalent


Download 74LS27 Triple 3-input NOR Gate Datasheet from the link given below.