74HC32 — Quad 2-Input OR Gate

Overview

The 74HC32 (SN74HC32) is a quad 2-input OR gate IC manufactured using high-speed silicon-gate CMOS technology. Containing four independent 2-input OR gates in a 14-pin DIP/SOIC package, it performs the Boolean function $Y = A + B$ in positive logic.

Operating from a wide supply voltage range of 2.0V to 6.0V DC, it combines low power CMOS consumption with high-speed switching speeds ( $7\text{ ns}$ propagation delay). It is widely used in digital logic designs for multi-source alarm trigger ORing, address decoding logic, and control signal combining.

Quick reference


Supply Voltage (`VCC`)	2.0 V to 6.0 V DC
Logic Family	High-Speed CMOS (74HC) / TTL Compatible (74HCT)
Independent Gates	4 (Quad 2-Input OR)
Propagation Delay	$7\text{ ns}$ typical at $VCC = 5.0\text{V}$
Output Drive Current	$\pm 5.2\text{ mA}$ at $VCC = 4.5\text{V}$
Package	14-pin DIP / SOIC-14 / TSSOP-14

Pinout (DIP-14 Package)

text

             ┌───┴───┐
          1A 1│ 1   14│ VCC
          1B 2│       │13 4B
          1Y 3│       │12 4A
          2A 4│ 74HC32│11 4Y
          2B 5│       │10 3B
          2Y 6│       │9  3A
         GND 7│       │8  3Y
             └───────┘

Pin	Name	Description
1	`1A`	Gate 1 Input A
2	`1B`	Gate 1 Input B
3	`1Y`	Gate 1 Output ( $1Y = 1A + 1B$ )
4	`2A`	Gate 2 Input A
5	`2B`	Gate 2 Input B
6	`2Y`	Gate 2 Output ( $2Y = 2A + 2B$ )
7	`GND`	Ground reference (0 V)
8	`3Y`	Gate 3 Output ( $3Y = 3A + 3B$ )
9	`3A`	Gate 3 Input A
10	`3B`	Gate 3 Input B
11	`4Y`	Gate 4 Output ( $4Y = 4A + 4B$ )
12	`4A`	Gate 4 Input A
13	`4B`	Gate 4 Input B
14	`VCC`	Power supply voltage (+2.0V to +6.0V DC)

Function & Truth Table (Per Gate)

Input A	Input B	Output Y
Low ( $L$ )	Low ( $L$ )	Low ( $L$ )
Low ( $L$ )	High ( $H$ )	High ( $H$ )
High ( $H$ )	Low ( $L$ )	High ( $H$ )
High ( $H$ )	High ( $H$ )	High ( $H$ )

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Supply Voltage	$V_{CC}$	2.0	5.0	6.0	V	DC
High-Level Input Voltage	$V_{IH}$	3.15	—	—	V	$V_{CC} = 4.5\text{V}$
Low-Level Input Voltage	$V_{IL}$	—	—	1.35	V	$V_{CC} = 4.5\text{V}$
Propagation Delay ( $A,B \rightarrow Y$ )	$t_{PD}$	—	7	15	ns	$V_{CC} = 4.5\text{V}, C_L = 50\text{pF}$
Output Drive Current	$I_{OUT}$	—	—	$\pm 5.2$	mA	$V_{CC} = 4.5\text{V}$
Quiescent Supply Current	$I_{CC}$	—	—	2.0	µA	$V_{IN} = V_{CC}\text{ or GND}$

Typical Applications

Multi-Sensor Fault Alarm ORing

Triggering an alarm buzzer if Sensor A OR Sensor B OR Sensor C detects a fault condition.