74HCT594D,118

Shift Registers Overview

The Nexperia 74HCT594D,118 is an 8-bit serial-in/serial or parallel-out shift register with a storage register, housed in an SO16 plastic small outline package (SOT109-1). It operates within a supply voltage range of 4.5 V to 5.5 V and supports ambient temperatures from -40 °C to +125 °C. The device features independent clocks for shift and storage registers, allowing the shift register to remain one clock pulse ahead when clocks are connected. Data shifts on LOW-to-HIGH transitions of the SHCP input, while transfer to the storage register occurs on STCP transitions. Inputs include clamp diodes for interfacing with voltages exceeding VCC.

Shift Registers Feature Summary

• Provides synchronous serial input and output capabilities with 8-bit parallel data availability.
• Features independent direct clear and clock inputs for both shift and storage registers.
• Ensures high noise immunity and low power dissipation through CMOS technology.
• Includes ESD protection exceeding specified JEDEC class levels for robust operation.

Shift Registers Applications

• Serial-to-parallel data conversion
• Remote control holding register

Shift Registers Procurement Notes

Verify the specific ordering suffix

Shift Registers Selection Notes

Select this component when TTL-compatible input levels are required for 5 V logic systems. The HCT variant ensures compatibility with standard TTL outputs while maintaining CMOS performance characteristics. Ensure the application environment stays within the specified temperature range of -40 °C to +125 °C. Confirm that the SO16 package dimensions align with the PCB footprint requirements for SOT109-1.

Shift Registers Part Context

This part belongs to the 74HCT series of high-speed CMOS logic devices manufactured by Nexperia. It is functionally compatible with other 74HCT shift registers but offers specific pinout and electrical characteristics defined by the 74HCT594 designation. The device is designed for general-purpose digital applications requiring reliable data shifting and storage in industrial and commercial environments.

Shift Registers Replacement Considerations

Direct functional substitutes include the 74HC594D,118, though it requires CMOS-level input signals rather than TTL levels. Other package variants such as 74HCT594PW or 74HCT594DB offer identical functionality in TSSOP16 or SSOP16 packages respectively. Verify input voltage compatibility when substituting HC variants into circuits designed for HCT inputs.

Shift Registers FAQ

How does the 74HCT594 handle data cascading?

The device includes a serial output (Q7S) that allows data to be shifted out from the last stage of the shift register. This output can be connected to the serial data input (DS) of another 74HCT594 to extend the shift register length.

What is the effect of connecting SHCP and STCP together?

If both clock inputs are connected together, the shift register will always be one clock pulse ahead of the storage register. Data loads into the shift register on the rising edge of the clock, and transfers to the storage register on the subsequent rising edge.