M74HC299B1R

Shift Registers Overview

The M74HC299B1R is an 8-bit parallel-in/parallel-out (PIPO) shift register with asynchronous clear and three-state outputs, manufactured using silicon gate C2MOS technology. It operates within a supply voltage range of 2V to 6V and supports a maximum clock frequency of 80MHz at 6V. The device features four operational modes: HOLD, SHIFT LEFT, SHIFT RIGHT, and LOAD DATA, selected via two function select inputs. It provides symmetrical output impedance and balanced propagation delays, ensuring high-speed performance comparable to equivalent LSTTL devices while maintaining low CMOS power dissipation.

Shift Registers Feature Summary

• Supports four distinct operational modes including data hold, bidirectional shifting, and parallel loading.
• Features asynchronous master reset functionality for immediate clearing of the register state.
• Provides three-state outputs controlled by active-low enable inputs to prevent bus contention.

Shift Registers Applications

• High-speed serial-to-parallel or parallel-to-serial data conversion in digital systems.
• Temporary data storage and buffering within microprocessor-based architectures.
• Implementation of addressable latches or bus driver circuits requiring tri-state control.

Shift Registers Procurement Notes

Verify that the specific B1R suffix corresponds to the Plastic DIP-20 package as documented in the official datasheet order codes. Confirm compatibility with your target PCB footprint and pin spacing requirements before finalizing component selection.

Shift Registers Selection Notes

Select this component when an 8-bit shift register with asynchronous clear and tri-state outputs is required. Ensure the operating environment stays within the specified -55°C to +125°C temperature range and that the supply voltage remains between 2V and 6V for optimal electrical characteristics.

Shift Registers Part Context

This part belongs to the M74HC299 series of high-speed CMOS logic devices produced by STMicroelectronics. It is designed to be pin and function compatible with the standard 74 Series 299 logic family, facilitating direct replacement in legacy designs while offering improved speed and lower power consumption typical of modern CMOS processes.

Shift Registers Replacement Considerations

Direct substitutes include other 8-bit PIPO shift registers with asynchronous clear and tri-state outputs from the same logic family. Verify pinout compatibility and electrical specifications against the original design requirements before substitution.