74LS20 Dual 4-input NAND 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. 74LS20 Dual 4-input NAND Gate contains two independent 4 input NAND gate

74LS20 Features

  • Two Independent NAND Gates
  • Standard Pin Configuration
  • Fast Switching Times
  • Operating Temperature up to 70°C
  • Standard TTL Switching Voltages

74LS20 Specifications

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

74LS20 Pinout Diagram

74LS20 Pin Description

Pin NoPin NameDescription
1A1NAND Gate 1 Input 1
2B1 NAND Gate 1 Input 2
3NCNo Connection
4C1 NAND Gate 1 Input 3
5D1 NAND Gate 1 Input 4
6X1 NAND Gate 1 Output
8X2 NAND Gate 2 Output
9A2 NAND Gate 2 Input 1
10B2 NAND Gate 2 Input 2
11NCNo Connection
12C2 NAND Gate 2 Input 3
13D2 NAND Gate 2 Input 4
14VCCPositive Supply

74LS20 Circuit


  • Freezer warning buzzer circuits
  • Automatic temperature control circuits

74LS20 Alternative Equivalent

74LS03, 74LS10

Download 74LS20 Dual 4-input NAND Gate Datasheet from the link given below.