SN74HC595N 8-Bit Shift Register Pinout
The SN74HC595N is an 8-bit serial-in, parallel-out shift register with an 8-bit storage register and 3-state output manufactured by Texas Instruments (TI). This IC is designed to expand digital I/O capabilities efficiently, making it ideal for driving LEDs, displays, and interfacing with microcontrollers. Housed in a PDIP-16 package, the SN74HC595N supports high-speed serial communication while minimizing the number of required microcontroller pins.
Overview of SN74HC595N
The SN74HC595N is an 8-bit shift register with serial-in and parallel-out functionality paired with an 8-bit D-type storage register. This storage register features parallel 3-state outputs for versatile applications. The design includes separate clock inputs for the shift register and the storage register, ensuring precise control. The shift register is equipped with a direct clear (SRCLR) input for quick resetting, a serial (SER) input for data entry, and cascading serial outputs for extending functionality. When the output-enable (OE) input is set high, the parallel outputs switch to a high-impedance state.
SN74HC595N Features
- 8-Bit Serial-In, Parallel-Out Shift Register: Facilitates efficient data handling and output.
- Wide Operating Voltage Range: Functions seamlessly across 2 V to 6 V.
- High-Current 3-State Outputs: Capable of driving up to 15 LSTTL loads.
- Low Power Consumption: Maximum ICC of 80 µA ensures energy efficiency.
- Fast Propagation Delay: Typical tpd of 13 ns for rapid performance.
- Output Drive Capability: Provides a ±6-mA drive at 5 V for robust output.
- Minimal Input Current: Input current remains under 1 µA, reducing overall power usage.
- Direct Clear on Shift Register: Enables quick reset functionality.
- MIL-PRF-38535 Compliance: For compliant products, all parameters are rigorously tested. Other products may not undergo testing for all parameters during production.
SN74HC595N Specifications
| Parameter | Value | Description |
|---|---|---|
| Manufacturer | Texas Instruments (TI) | Original manufacturer of the IC |
| Part Number | SN74HC595N | Serial-in, parallel-out shift register |
| Logic Family | HC (High-Speed CMOS) | CMOS technology for high performance |
| Number of Outputs | 8 | 8-bit serial to parallel output |
| Operating Voltage | 2V to 6V | Recommended supply voltage range |
| Max Clock Frequency | 25 MHz | Maximum operating clock frequency |
| Output Type | Tri-State | Outputs can be in high-impedance state |
| Input Voltage (High) | 2V - 6V | High-level input voltage |
| Input Voltage (Low) | 0V - 1.5V | Low-level input voltage |
| Propagation Delay | 19 ns (typical) | Time delay between input and output |
| Max Output Current | ±35 mA per pin | Maximum output drive current |
| Operating Temperature | -40°C to 85°C | Industrial temperature range |
| Power Consumption | Low power consumption | Typical CMOS low-power design |
| Package Type | DIP-16 (N Package) | Dual Inline Package with 16 pins |
| Latch Enable (LE) | Supported | Control for output latch operation |
| Serial Data In (DS) | Supported | Serial data input functionality |
| RoHS Compliant | Yes | Environmentally friendly component |
SN74HC595N Applications
Network Switches
The SN74HC595N shift register is commonly used in network switches for expanding the control of multiple relays, LEDs, or other devices that need to be activated or monitored. It allows for the efficient control of a large number of ports or status indicators from a microcontroller (MCU) or microprocessor (MPU) with limited GPIO pins. By serially shifting data, the SN74HC595N helps minimize the pin count required for controlling complex switching functions in networking hardware, improving the scalability and flexibility of network switches.
Power Infrastructure
In power infrastructure systems, particularly for smart grids and control systems, the SN74HC595N is used to control and monitor multiple components with minimal pin usage. These may include voltage regulators, circuit breakers, and power distribution panels. By utilizing its shift-register capabilities, the SN74HC595N can cascade control signals across various subcomponents, ensuring reliable performance in large-scale power management applications. This capability helps streamline the design of control systems that need to scale while keeping power consumption and wiring minimal.
LED Displays
SN74HC595N is widely used in LED display applications, where it is employed to drive multiple LEDs or a matrix of LEDs. The shift register allows serial data to control large numbers of LEDs, reducing the need for excessive wiring and GPIO pins on the controlling MCU or MPU. Whether it's for alphanumeric displays, status indicators, or large-scale signage, the SN74HC595N helps to simplify the design while ensuring that each LED can be individually addressed, all while maintaining efficient power usage and control logic.
Servers
In server applications, the SN74HC595N shift register facilitates the control of diagnostic LEDs, fan speeds, and other status indicators on server racks. By using the serial-in and parallel-out configuration of the SN74HC595N, servers can manage multiple indicators and sensors with a limited number of control pins. This is particularly beneficial in server management systems, where space and pin count are often constrained. The shift register helps maintain efficient communication between the server's MCU/MPU and the various components that need to be monitored and controlled.
Expand the GPIO Pin on an MCU/MPU
The SN74HC595N is primarily used to expand the General Purpose Input/Output (GPIO) capabilities of microcontrollers (MCUs) or microprocessors (MPUs). When a system needs more output pins than the MCU/MPU can provide, the SN74HC595N allows the addition of several output pins without the need for additional microcontroller resources. This is achieved by serially shifting data through the chip, enabling the control of multiple devices such as LEDs, motors, or relays. It is particularly useful in applications where the microcontroller is limited in terms of available pins but needs to control a large number of outputs.
Cascading Applications
Cascading refers to linking multiple SN74HC595N shift registers together to expand the number of controlled outputs further. In applications requiring more outputs than a single shift register can provide, cascading multiple SN74HC595N units allows the user to control a virtually unlimited number of devices with just a few control lines. This feature is commonly used in large-scale projects, such as driving extensive LED matrices, controlling large numbers of motors or relays, or interfacing with various other hardware components in a modular fashion, all from a single MCU/MPU.
High Logic Level Controller
The SN74HC595N shift register can be used as a high logic level controller to interface low-voltage microcontrollers or microprocessors with high-voltage systems. This capability is important in applications where the control signals need to drive higher-voltage devices, such as motors, high-power LEDs, or other industrial equipment. The SN74HC595N's ability to handle higher output logic levels ensures that the signal integrity and power requirements of the system are met while using lower-voltage control signals, thus protecting the MCU/MPU from potentially damaging high voltages.
Pin Configuration and Functions
Pin No. | Pin Name | Description |
1,2,3,4,5,6,7 | Output Pins (QB to QH) | The SN74HC595N has 8 output pins out of which 7 are these pins. They can be controlled serially |
8 | Ground | Connected to the Ground of the circuit |
9 | (QH) Serial Output | This pin is used to connect more than one SN74HC595N as cascading |
10 | (MR) Master Reset | Resets all outputs as low. Must be held high for normal operation |
11 | (SH_CP) Clock | This is the clock pin to which the clock signal has to be provided from MCU/MPU |
12 | (ST_CP) Latch | The Latch pin is used to update the data to the output pins. It is active high |
13 | (OE) Output Enable | The Output Enable is used to turn off the outputs. Must be held low for normal operation |
14 | (DS) Serial Data | This is the pin to which data is sent, based on which the 8 outputs are controlled |
15 | (Q0) Output | The first output pin. |
16 | Vcc | This pin powers the IC, typically +5V is used. |
评论
发表评论