74266 Quad 2-Input Exclusive-NOR Gates
The 74266 is a chip with four open-collector XNOR gates. This type of output makes it simple to connect it to other chips that use different logic levels. But it also means you cant use this chip as a direct replacement for a normal XNOR gate chip.
In this guide, you will learn all about this chip and how you can use its XNOR gates in your own circuit.
What does the 74LS266 do?
The 74266 gives you four open-collector XNOR gates that can be used individually. AnXNOR gateis alogic gatethat outputs 1 (HIGH) if its inputs are equal (both 1 or both 0). In the truth table below, you can see what the output will be for any given input:
The truth table for the XNOR gate
How To Use This Chip
The 74Ls266 comes in a 14-pin package, and you need to connect it to power before you can use it. Most 7400 ICs support a VCC voltage of 5V. One difference between the HC and LS versions of the chip is that the 74HC266 supports 2V to 6V, while the 74LS266 only supports 5V.
Once its connected, you can use any of the four open-collector XNOR gates inside.
The 74HC266/74LS266 IC connected to power
This chip usesopen-collector outputs. That means you can only
sink
current (current can flow into the chip), not
source
it (current cannot flow out of the chip).
Each gate output of the 74HC266 can sink about 4 mA when powered with 5V. While the 74LS266 can usually sink about 8 mA of current. These values can vary between manufacturers of the chip though.
74266 Pinout
The 74266 has 14 pins and contains four open-collector XNOR gates laid out as shown in the pinout diagram below. Each gate has the open-collector symbol, to remind you of the type of output:
Pin #
Type
Description
1
Input
Input to the first XNOR gate.
2
Input
Input to the first XNOR gate.
3
Output
Open-collector output from the first XNOR gate.
4
Input
Input to the second XNOR gate.
5
Input
Input to the second XNOR gate.
6
Output
Open-collector output from the second XNOR gate.
7
Power
Connect to ground (GND).
8
Output
Open-collector output from the third XNOR gate.
9
Input
Input to the third XNOR gate.
10
Input
Input to the third XNOR gate.
11
Output
Open-collector output from the fourth XNOR gate.
12
Input
Input to the fourth XNOR gate.
13
Input
Input to the fourth XNOR gate.
14
Power
Positive power supply (VCC). Connect to +5V power.
Technical Specifications
Physical
Case/Package
PDIP
Contact Plating
Gold
Mount
Through Hole
Number of Pins
14
Technical
High-Level Output Current
-100 A
Logic Function
XNOR
Low-Level Output Current
8 mA
Max Operating Temperature
70 C
Max Output Current
8 mA
Max Supply Voltage
5.25 V
Min Operating Temperature
0 C
Min Supply Voltage
4.75 V
Number of Bits
4
Number of Channels
4
Number of Circuits
4
Number of Elements
4
Number of Gates
4
Number of Input Lines
2
Number of Inputs
2
Number of Output Lines
1
Number of Outputs
1
Operating Supply Voltage
5 V
Output Current
8 mA
Propagation Delay
30 ns
Quiescent Current
8 mA
Termination
Through Hole
Turn-On Delay Time
30 ns
74266 Datasheet
More styles you’ll love.
Reviews (0)
There are no reviews yet.