MM74HC259SJ

Product Overview

• Category: Integrated Circuit (IC)
• Use: Data Storage and Control
• Characteristics: High-Speed, 8-Bit Addressable Latch/Shift Register
• Package: Plastic Dual-In-Line Package (PDIP)
• Essence: A versatile IC that combines the functionality of a latch and a shift register in one device.
• Packaging/Quantity: Available in tubes or reels, with varying quantities depending on the supplier.

Specifications

• Supply Voltage Range: 2V to 6V
• High-Level Input Voltage: 2V to VCC
• Low-Level Input Voltage: GND to 0.8V
• High-Level Output Current: -0.4mA
• Low-Level Output Current: 8mA
• Operating Temperature Range: -55°C to +125°C
• Maximum Clock Frequency: 25MHz

Detailed Pin Configuration

The MM74HC259SJ has a total of 16 pins, each serving a specific function:

1. GND: Ground reference voltage
2. D0-D7: Data inputs for the latch/shift register
3. MR: Master Reset input
4. SH/LD: Shift/Load control input
5. CLK: Clock input
6. QA-QH: Outputs Q0-Q7
7. VCC: Positive supply voltage

Functional Features

• Latch and Shift Register: The MM74HC259SJ can operate as an 8-bit addressable latch or a shift register, providing flexibility in data storage and control applications.
• Addressability: Each bit of the register can be individually addressed, allowing selective reading or writing of data.
• Parallel or Serial Operation: The device can be configured to perform parallel loading or serial shifting of data, depending on the control input.
• High-Speed Operation: With a maximum clock frequency of 25MHz, the MM74HC259SJ is suitable for high-speed applications.
• Compatibility: The IC is compatible with other HC family devices, ensuring seamless integration into existing systems.

Advantages and Disadvantages

Advantages: - Versatility: Combines latch and shift register functionality in one device. - Addressability: Individual bit addressing allows selective data manipulation. - High-Speed Operation: Suitable for time-critical applications.

Disadvantages: - Limited Output Current: Low-level output current is limited to 8mA. - Temperature Range: Operating temperature range is limited to -55°C to +125°C.

Working Principles

The MM74HC259SJ operates based on the principles of latch and shift register circuits. When the SH/LD input is low, the device functions as a shift register, allowing data to be shifted in or out serially. On the rising edge of the clock signal (CLK), the data is transferred to the next stage.

When the SH/LD input is high, the device operates as a latch, capturing the data present at the inputs and holding it until the next latch operation. The addressability feature allows individual bits to be selected for reading or writing.

Detailed Application Field Plans

The MM74HC259SJ finds applications in various fields, including:

1. Digital Communication Systems: Used for data storage and control in communication protocols such as UART, SPI, and I2C.
2. Industrial Automation: Enables precise control of devices and sensors in automated systems.
3. Automotive Electronics: Utilized in vehicle control units for data processing and control.
4. Consumer Electronics: Integrated into electronic devices for data storage and control purposes.
5. Embedded Systems: Incorporated into microcontroller-based systems for efficient data handling.

Detailed and Complete Alternative Models

1. 74HC595: 8-bit shift register with output latches.
2. CD4015: Dual 4-bit static shift register.
3. SN74LS164: 8-bit serial-in parallel-out shift register.

These alternative models offer similar functionality to the MM74HC259SJ and can be used as replacements depending on specific requirements.

In conclusion, the MM74HC259SJ is a versatile IC that combines the functionalities of a latch and a shift register. With its high-speed operation, addressability, and compatibility with other HC family devices, it finds applications in various fields such as digital communication systems, industrial automation, automotive electronics, consumer electronics, and embedded systems. While it has limitations in output current and operating temperature range, there are alternative models available for different application scenarios.