74HC595 8-Bit Serial-to-Parallel Shift Register with Output Latch – 16-Pin DIP
The 74HC595 is an 8-bit serial-in, parallel-out shift register with an integrated 8-bit storage register (output latch) and 3-state outputs. It allows a microcontroller to control eight digital outputs using only a few control lines.
Multiple 74HC595 ICs can be daisy-chained, making it easy to expand the number of outputs for LEDs, displays, relays, indicators, and other digital control applications.
Technical Specifications
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IC Type: Serial-to-Parallel Shift Register
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Shift Register: 8-Bit
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Storage / Latch Register: 8-Bit
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Data Input: Serial
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Main Outputs: 8 Parallel Outputs
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Output Type: 3-State
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Serial Output: Available for Cascading
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Shift Clock: Separate Clock Input
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Storage Register Clock: Separate Latch Clock
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Output Enable: Active LOW
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Shift Register Clear: Active LOW
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Logic Family: 74HC High-Speed CMOS
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Package: 16-Pin DIP as supplied
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Function: Serial-In to Parallel-Out Data Conversion
How It Works
Serial data is shifted into the internal 8-bit shift register one bit at a time using the serial data input and shift clock.
Once the required 8-bit value has been loaded, the storage-register clock transfers the complete value to the output latch. This allows all eight parallel outputs to update together rather than changing individually while data is being shifted.
Output Enable & Clear
The Output Enable (OE) input controls the 3-state output drivers. When the outputs are disabled, they enter a high-impedance state without erasing the stored data.
The Shift Register Clear (SRCLR/MR) input clears the internal shift register. It does not directly function as an asynchronous clear for the output storage register.
Cascading Multiple 74HC595 ICs
The serial output can be connected to the serial input of another 74HC595, allowing multiple devices to be daisy-chained.
For example:
1 × 74HC595 = 8 Outputs
2 × 74HC595 = 16 Outputs
4 × 74HC595 = 32 Outputs
This makes the IC particularly useful when a microcontroller has limited GPIO pins.
Applications
Suitable for Arduino, ESP32 and other microcontroller projects, LED control, 7-segment displays, LED matrices, digital indicators, relay control through suitable driver circuits, GPIO expansion, display interfaces, control panels, robotics, educational electronics, and breadboard prototyping.
Important Note
The 74HC595 is a logic IC and should not be used to directly drive high-current loads such as motors, large relays, solenoids, or high-power LEDs. Use suitable transistors, MOSFETs, or driver ICs when controlling higher-current devices.
When interfacing with microcontrollers operating at different logic voltages, verify the supply voltage and input HIGH/LOW thresholds for the exact 74HC595 device being used.
Package Includes
1 × 74HC595 8-Bit Serial-to-Parallel Shift Register IC
