SN74HC164D

The SN74HC164 is an 8-bit serial-in, parallel-out shift register featuring two AND-gated serial inputs and an asynchronous clear input.

The serial inputs A and B provide complete control over incoming data. A LOW level at either input inhibits entry of new data and causes the first flip-flop to be reset LOW on the next clock pulse.

When both serial inputs are HIGH, new data can be shifted into the register.

Data is shifted on the low-to-high transition of CLK.

The CLR input provides a direct asynchronous clear function.

Key Features

• Wide operating voltage range: 2 V to 6 V
• 8-bit shift register
• AND-gated serial inputs
• Fully buffered clock and serial inputs
• Direct asynchronous clear
• Low power consumption: 80 µA maximum ICC
• Typical propagation delay: 20 ns
• ±4 mA output drive at 5 V
• Maximum input current: 1 µA
• Can drive up to 10 LSTTL loads
• Available in SOIC, PDIP, SO, TSSOP, CDIP, CFP and LCCC packages

Applications

• Programmable logic controllers
• Appliances
• Video display systems
• Output expansion
• Digital control systems

Practical repair note

The SN74HC164 is particularly useful when a controller needs 8 parallel outputs while using only a few control lines.

A typical connection is:

DATA → A/B → CLK → Q0…Q7

For troubleshooting, first check VCC, CLR and CLK, then verify the A/B logic levels and observe whether the Q outputs shift after each positive CLK edge.

Tags: SN74HC164D, SN74HC164, 74HC164, Shift Register, 8-Bit, SIPO, CMOS, SOIC-14, 2V, 6V