SN74HC165NSR

The SN74HC165NSR is a serial-in/parallel-out shift register from Texas Instruments. It is classified under the Logic - Shift Registers category. This device is used mainly for converting serial data into parallel data, which is one of the common tasks for digital logic systems.

The device has 8-bits of parallel out data, a serial input (SI) and a synchronous serial clock input (CP). The logic family of the IC is HC logic which is suitable for low-voltage and high-speed applications. The maximum supply voltage required is 5.5 V.

Working Principle

The principle of operation of the shift register is that the data applied at the serial input is shifted bit-by-bit through the shift register on the rising edge of the clock pulse applied to the clock input. The serial data which can be in either logic ‘1’ or logic ‘0’ at a given time is shifted into each flip-flop present in the shift register one at a time.

The last bit of data is transferred to the 8th output at the 8th clock edge. This is the parallel output of the shift register. Thus, the data at serial inputs is shifted serially through each of the flip-flops and accumulated at the parallel output in the form of parallel data.

Applications

SN74HC165NSR shift registers are widely used in a variety of embedded system applications. Few of the applications are listed below.

• Data Multiplexing.
• Serial Data Interfacing.
• Serial to Parallel Conversion.
• Interface circuits for memory and I/O devices.
• Automatic Testing equipment.
• Clocking and timing applications.

Conclusion

The SN74HC165NSR shift register from Texas Instruments is an 8-bit serial to parallel shift register. It is classified under the Logic - Shift Registers category and is used in a variety of embedded system applications. The device has serial data input pins and parallel output pins, and a synchronous serial clock pin. The device operates by shifting the data serially and accumulating it at the parallel output pins.