Texas Instruments SN74HC165D

The Texas Instruments SN74HC165D is an 8-bit serial-in, parallel-out shift register. It is part of the 74HC family of high-speed CMOS logic devices. The device operates from a wide voltage range and is designed for high-speed data processing and control applications, making it suitable for various digital applications. Functions: 1. Serial-to-Parallel Conversion: It receives serial data on its input and outputs it in parallel after shifting. 2. Data Storage: Holds the state of the input for output at a specific time, useful for data processing. 3. Cascade Capability: Multiple SN74HC165D chips can be cascaded to read more than 8 bits of data. 4. Clock-Controlled Operation: Operates with a clock, allowing synchronous operation for data shifting. Applications: - Data Acquisition: Used in systems that need to acquire input from multiple sensors. - Microcontroller Interfaces: Expanding the number of digital I/O pins of microcontrollers. - Digital Communication: In applications needing serial communication protocols. - Control Systems: For reading switches, buttons, or other binary devices in a control system. Alternative Parts: 1. 74HC595: An 8-bit serial-in, parallel-out shift register with an additional latch output. 2. CD4021: A similar shift register but with lower speed and CMOS logic levels. 3. SN74HC166: A parallel-in, serial-out shift register which may be suitable for different data acquisition needs. Embedded Modules: Some embedded development boards may include the SN74HC165D or similar ICs: - Arduino Shields: Some Arduino-compatible shields incorporate shift registers for extending inputs. - Raspberry Pi HATs: Certain HATs include shift registers for managing more inputs. - FPGA Development Boards: Often use shift registers for interfacing various components. Related Q&A: 1. Q: What is the maximum clock frequency for the SN74HC165D? A: The maximum clock frequency is determined by the supply voltage and load capacitance, but it can typically operate up to 25 MHz. 2. Q: How do you connect multiple SN74HC165D chips together? A: You can cascade multiple chips by connecting the QH' output of the first chip to the SER input of the next, ensuring the same clock and latch signals are shared across all chips. 3. Q: Can the SN74HC165D be used with a 5V and 3.3V microcontroller? A: Yes, the SN74HC165D can be powered by 5V, and it can interface with devices operating at 3.3V logic levels as long as the voltage levels are compatible. 4. Q: What is the difference between serial-in parallel-out and parallel-in serial-out shift registers? A: Serial-in parallel-out shift registers take data in serially and output it in parallel, while parallel-in serial-out shift registers take a parallel input and shift it out one bit at a time serially. 5. Q: How can you use the SN74HC165D to read button states? A: Connect buttons to the inputs of the SN74HC165D, then clock the register to shift the input states out in parallel, allowing a microcontroller to read the button states efficiently.