74LS348 8-Input Priority Encoder IC With 3-State Output

Contents hide

The 74LS348 is a 74XXYY IC series priority encoder. The 74LS348 IC is an eight input priority encoder that provides the 8-line to 3-line function. The outputs (A0–A2) and inputs (0–7) are active low. The active-low input which has the highest priority (input 7 has the highest) is represented on the outputs (output A0 is the lowest bit). The 74LS348 has a built-in Schottky barrier diode to process for high speed. It features priority decoding of the inputs to ensure that only the highest-order data line is encoded. The output of the IC always comes in TTL which makes it easy to work with other TTL devices and microcontrollers.

Buy Now

What is a Priority Encoder?

Simply speaking, a priority encoder is a type of encoder that improves upon the design of a simple encoder. It is, in a sense, the dual or opposite of a decoder. A priority encoder provides ‘n’ bits of binary coded output representing the position of the highest order active input of 2ⁿ inputs. If two or more inputs are high at the same time, the input having the highest priority will take precedence.

74LS348 Key Features & Specifications

Technology Family: LS
Function: Encoder, Multiplexer
Configuration: 8:3
Channels (#) 1
VCC (Min) (V) 4.75
VCC (Max) (V) 5.25
Typical Data Delay:15 ns
Typical Power Dissipation: 60 mW
Input type TTL
Output type TTL

74LS348 Pinout

Pin No.	Pin Name	Description
1	4	Octal Input Pin 1
2	5	Octal Input Pin 2
3	6	Octal Input Pin 3
4	7	Octal Input Pin 4
5	EI	Active Low Enable Pin
6	A2	Binary Output Pin A2
7	A1	Binary Output Pin A1
8	GND	Ground Pin
9	A0	Binary Output Pin A0
10	0	Octal Input Pin 10
11	1	Octal Input Pin 11
12	2	Octal Input Pin 12
13	3	Octal Input Pin 13
14	GS	Gray Output Pin GS
15	EO	Gray Output Pin EO
16	Vcc	Chip Supply Voltage

Applications

The 74LS348 Encoder IC has a wide array of applications, a few of them are mentioned below:

Priority encoders can be used to convert the rotary or angular position of a compass to a digital code, so that it can be used for navigational purposes.