SN74HC164DR Detai LED explanation of pin function specifications and circuit principle instructions
The "SN 74HC164D R" is a model from Texas Instruments. It belongs to the 74HC (High-speed CMOS) logic family and is specifically a Shift Register IC. The 'DR' suffix indicates that the part comes in a SOIC-14 (Small Outline Integrated Circuit) package, which has 14 pins. Below is the detai LED explanation of its pin function specifications, circuit principle, and FAQs.
Pin Function Specifications and Circuit Principle Instructions
The SN74HC164 is an 8-bit serial-in, parallel-out shift register. It operates using CMOS logic and is used for expanding input/output in digital circuits, particularly where a serial input can be shifted and then outputted in parallel.
Package Type: SOIC-14 (Surface Mount Package): This package has 14 pins in total. Pin Function Table: Pin Number Pin Name Pin Function Description 1 QH (Pin 1) Output of the first bit (serial out). This pin is connected to the first stage of the shift register, representing the serial output of data in parallel-out operation. 2 QH' (Pin 2) Active low output, often used for signal inversion or as a complement to QH. 3 Q0 (Pin 3) First parallel output bit. This is the most significant bit (MSB) in the shift register. 4 Q1 (Pin 4) Second parallel output bit. 5 Q2 (Pin 5) Third parallel output bit. 6 Q3 (Pin 6) Fourth parallel output bit. 7 Q4 (Pin 7) Fifth parallel output bit. 8 Q5 (Pin 8) Sixth parallel output bit. 9 Q6 (Pin 9) Seventh parallel output bit. 10 Q7 (Pin 10) Eighth parallel output bit. 11 Clock (Pin 11) Clock input. Each pulse on this pin shifts the data in the shift register by one bit. The serial data is shifted out from the first bit (QH) when the clock pulse is triggered. 12 CLEAR (Pin 12) Active low reset input. When this pin is low, the entire shift register is cleared, meaning all outputs will be zero. 13 DATA (Pin 13) Serial data input. The data is shifted in on the rising edge of the clock. 14 GND (Pin 14) Ground. This is the reference ground for the IC. Circuit Principle:The SN74HC164 functions as a serial-to-parallel shift register. Here's how it works:
Serial Data Input (DATA Pin 13): Data is inputted serially, bit by bit, into the shift register. Clock (CLOCK Pin 11): Each clock pulse moves the data one step to the next stage in the register. Parallel Outputs (Q0 to Q7, Pins 3-10): Once the data is shifted in, it is available on the parallel output pins. These outputs provide the parallel representation of the input data. Clear (CLEAR Pin 12): Clears all data in the shift register when triggered (set low). Serial Output (QH Pin 1): The data that is shifted out is available at the serial output pin.FAQs (Frequently Asked Questions)
1. What is the purpose of the SN74HC164DR IC? The SN74HC164DR is a serial-in, parallel-out shift register that allows serial data to be converted into parallel outputs. 2. What is the significance of the CLOCK pin? The CLOCK pin (Pin 11) controls the shifting of data. Each clock pulse shifts the data stored in the register by one bit. 3. How is the CLEAR pin used? The CLEAR pin (Pin 12) is an active low reset. When it is held low, it clears all the stored data in the shift register, resetting the outputs to zero. 4. What is the role of the DATA pin? The DATA pin (Pin 13) is where serial data is inputted into the shift register. Data is shifted in on the rising edge of the clock pulse. 5. How many parallel outputs does the SN74HC164 provide? The SN74HC164 provides 8 parallel outputs: Q0 to Q7 (Pins 3-10). 6. How does data shift through the shift register? Data shifts through the shift register with each clock pulse, moving from the serial input to the parallel outputs. 7. Can the SN74HC164 be used for bidirectional communication? No, the SN74HC164 is a unidirectional shift register, meaning data only flows from serial input to parallel output, not the other way around. 8. What is the voltage range for operation? The SN74HC164 operates within a voltage range of 2V to 6V. 9. What happens if the CLEAR pin is triggered while data is shifting? If the CLEAR pin is triggered (set low) during shifting, all data in the shift register will be cleared, and the outputs will reset to zero. 10. What are the output states when the shift register is first powered on? When first powered on, all outputs (Q0 to Q7) are initialized to zero. 11. Can multiple SN74HC164 chips be cascaded together? Yes, multiple SN74HC164 ICs can be cascaded to increase the number of parallel outputs. 12. What happens when the CLOCK pin receives multiple pulses rapidly? If the CLOCK pin receives multiple pulses in quick succession, the data shifts at a higher rate, moving through the register more quickly. 13. Is the SN74HC164 compatible with both TTL and CMOS logic? Yes, the SN74HC164 is a CMOS IC, but it is also compatible with TTL logic levels. 14. What is the current consumption of the SN74HC164? The current consumption is typically 4 µA at 5V supply voltage. 15. Can the SN74HC164 be used in high-speed applications? Yes, the SN74HC164 is capable of high-speed operation, with a maximum clock frequency up to 25 MHz (depending on supply voltage). 16. What happens if the DATA input is left floating? If the DATA input is left floating, the input may be unstable, leading to unpredictable behavior. It is recommended to tie unused inputs to a known state. 17. How is the serial data input clocked into the shift register? The serial data is clocked in on the rising edge of the CLOCK signal. Each pulse moves the serial data into the register. 18. Can the SN74HC164 be used in logic level conversion applications? Yes, it can be used in logic level conversion applications by interfacing with other logic families or voltage levels, provided the voltage levels are within the specified range. 19. Is there a version of the SN74HC164 with more parallel outputs? The SN74HC164 is an 8-bit shift register. For more outputs, you would need to cascade multiple chips or use a different shift register with more bits. 20. Can the outputs of the SN74HC164 be used directly to drive LEDs? Yes, the outputs can drive LEDs directly, but current-limiting resistors are recommended to protect the LEDs and the IC from excessive current.Conclusion
The SN74HC164DR is a versatile 8-bit serial-in, parallel-out shift register IC with a range of applications in digital circuits. Its ability to convert serial data to parallel outputs makes it invaluable for various control and signal processing systems. The IC's clear pin, clock control, and serial data input/output are key to its operation, and understanding the function of each pin is essential for integrating this chip into your projects.
