Overview

The 74HC00 (SN74HC00) is a quad 2-input NAND gate IC manufactured using high-speed silicon-gate CMOS technology. Containing four independent 2-input NAND gates in a 14-pin DIP/SOIC package, it performs the Boolean function Y=A⋅B‾Y = \overline{A \cdot B} in positive logic.

The NAND gate is a universal logic gate; any basic logic function (AND, OR, NOT, NOR, XOR, SR Latch) can be constructed using only 74HC00 ICs. Operating over a supply range of 2.0V to 6.0V DC, it offers low CMOS power consumption with high-speed switching speeds (7 ns7\text{ ns} propagation delay).

Quick reference

Supply Voltage (VCC)2.0 V to 6.0 V DC
Logic FamilyHigh-Speed CMOS (74HC) / TTL Compatible (74HCT)
Independent Gates4 (Quad 2-Input NAND)
Propagation Delay7 ns7\text{ ns} typical at VCC=5.0VVCC = 5.0\text{V}
Output Drive Current±5.2 mA\pm 5.2\text{ mA} at VCC=4.5VVCC = 4.5\text{V}
Package14-pin DIP / SOIC-14 / TSSOP-14

Pinout (DIP-14 Package)

text
             ┌───┴───┐
          1A 1│ 1   14│ VCC
          1B 2│       │13 4B
         1/Y 3│       │12 4A
          2A 4│ 74HC00│11 4/Y
          2B 5│       │10 3B
         2/Y 6│       │9  3A
         GND 7│       │8  3/Y
             └───────┘
PinNameDescription
11AGate 1 Input A
21BGate 1 Input B
31/YGate 1 Output (1Y=1A⋅1B‾1Y = \overline{1A \cdot 1B})
42AGate 2 Input A
52BGate 2 Input B
62/YGate 2 Output (2Y=2A⋅2B‾2Y = \overline{2A \cdot 2B})
7GNDGround reference (0 V)
83/YGate 3 Output (3Y=3A⋅3B‾3Y = \overline{3A \cdot 3B})
93AGate 3 Input A
103BGate 3 Input B
114/YGate 4 Output (4Y=4A⋅4B‾4Y = \overline{4A \cdot 4B})
124AGate 4 Input A
134BGate 4 Input B
14VCCPower supply voltage (+2.0V to +6.0V DC)

Function & Truth Table (Per Gate)

Input AInput BOutput Y
Low (LL)Low (LL)High (HH)
Low (LL)High (HH)High (HH)
High (HH)Low (LL)High (HH)
High (HH)High (HH)Low (LL)

Specifications

ParameterSymbolMinTypMaxUnitConditions
Supply VoltageVCCV_{CC}2.05.06.0VDC
High-Level Input VoltageVIHV_{IH}3.15——VVCC=4.5VV_{CC} = 4.5\text{V}
Low-Level Input VoltageVILV_{IL}——1.35VVCC=4.5VV_{CC} = 4.5\text{V}
Propagation Delay (A,B→YA,B \rightarrow Y)tPDt_{PD}—715nsVCC=4.5V,CL=50pFV_{CC} = 4.5\text{V}, C_L = 50\text{pF}
Output Drive CurrentIOUTI_{OUT}——±5.2\pm 5.2mAVCC=4.5VV_{CC} = 4.5\text{V}
Quiescent Supply CurrentICCI_{CC}——2.0µAVIN=VCC or GNDV_{IN} = V_{CC}\text{ or GND}

Typical Applications

1. NAND SR Latch (Flip-Flop)

Cross-coupling two NAND gates creates an active-LOW Set-Reset (S‾\overline{S}-R‾\overline{R}) latch.

text
  Set (/S) ─────► [Pin 1: 1A]   [Pin 3: 1Y] ──┬──► Output Q
                       │                      │
                       └───[Cross Feedback]───┼──┐
                                              │  │
  Reset (/R) ───► [Pin 5: 2B]   [Pin 6: 2Y] ──┴──┼──► Output /Q
                       │                         │
                       └─────────────────────────┘

Common mistakes

  • Leaving unused NAND inputs floating: Floating inputs on pins 4, 5, 9, 10, 12, 13 cause internal switching noise and excessive supply current. Tie unused inputs to VCCV_{CC} or GND.
  • Confusing 74HC00 pinout with CD4011 pinout: Although both are Quad 2-Input NAND ICs, their pin layouts differ. On 74HC00, outputs are on pins 3, 6, 8, 11; on CD4011, outputs are on pins 3, 4, 10, 11.
  • Driving 74HC00 inputs with 3.3V logic when powered from 5V: When powered from 5V5\text{V}, the 74HC00 requires VIH≥3.15VV_{IH} \ge 3.15\text{V}. Use 74HCT00 for direct 3.3V logic compatibility.

Notes

  • 74HC00 vs CD4011: 74HC00 operates up to 6V DC with 7ns delay; CD4011 operates up to 18V DC with 60ns delay.

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