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SN74LS166 8-Bit Shift Register

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The SN74LS166AN is an 8-bit parallel-load serial-out Shift Register compatible with most other TTL logic families. This parallel-in or serial-in, serial-out shift register has a complexity of 77 equivalent gates on a monolithic chip. It features gated clock inputs and an overriding clear input. The parallel-in or serial-in modes are established by the shift/load input.

 

Pin Description of SN74LS166:

Pin Number

Pin Name

Description

2, 3, 4, 5,  10, 11, 12, 14

A to H

Parallel Data inputs. Data on these inputs are asynchronously entered in parallel into the internal flip–flops when the Serial Shift/Parallel Load input is low

13

QH

 Complementary Shift Register output Pin

1

SER

Serial Input Pin. When the Serial Shift/Parallel Load input

is high, data on this pin is serially entered into the first stage

of the shift register

6, 7

CLK INH & CLK

Clock inputs. These two clock inputs function identically

9

CLR

 Clear pin

15

SH/LD

Data–entry control input.

8

VSS

Ground

16

VCC

Supply Voltage – 5V, 10V, 15V

 

Features of SN74LS166:

  • 8-bit,  Serial/Parallel to Serial Shift register
  • Operating Voltage: 3V to 18V
  • Supply Voltage - Max:5.25 V
  • Propagation Delay Time: 25 ns
  • Max. Clock Frequency: 35MHz
  • Operating Temperature Range: 0C to + 70 C
  • Available in 16-pin PDIP, GDIP, PDSO packages

Note: Complete Technical Details can be found at the SN74LS166 datasheet give at the end of this page.

 

Alternatives shift Registers: 

Name

Type

74LS379

Quad Parallel Shift Register

4014

4 Bit static shift register

CD4035

8 Bit Shift Register

74LS323

8 Bit Shift/Storage Register

74LS164

S/P Shift Register

74HC595

Dual 4 Bit Static Register

74LS299

8 Bit Shift/Storage Register

 

Where to use SN74LS166 IC

The SN74LS166 has an 8-bit parallel in or serial-in, serial-out Shift Register. Meaning it can receive (input) get data serially or parallel and control output pins in Serial. This comes in very handy where one does not have enough GPIO pins on our MCU/MPU to control the required number of outputs. It is often used in projects where relatively a large number of LEDs have to be controlled through the Microcontroller. It can also be used to interface the LCD screen since it can act as the data bit for the LCD displays.

 

How to use SN74LS166

The SN74LS166 shift register is commonly used with microcontrollers or microprocessors to expand the GIPO functionalities. SN74LS166 needs 4 lines of a microcontroller. One for the Clock, one to the enable the clock, one for shifting the bits, and one for the serial data transfer. To use SN74LS166 with microcontroller connect these four pins (SER, CLK INH & CLK, and SH/LD) to GPIO pins of the microcontroller. Input pins (A to H) can be connected to some type of input like buttons, switches, etc.

 

Applications of SN74LS166:

  • Counters, Registers
  • Arithmetic-unit registers
  • Shift-left -shift-right registers
  • Serial-to-parallel/parallel-to-serial conversions
  • Sequence generation
  • Control circuits
  • Code conversion

 

2D Model of SN74LS166 (PDIP):

SN74LS166 Dimensions

 

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