74VHCT574ATTR

Overview

The STMicroelectronics 74VHCT574ATTR is an octal D-type flip-flop featuring three-state non-inverting outputs, fabricated using VHCT CMOS technology. It operates within a supply voltage range of 4.5V to 5.5V and supports a maximum clock frequency of 100 MHz. The device exhibits a typical propagation delay of 12ns at 5V with 50pF load. It provides symmetrical output currents of 12mA for both high and low states, with a maximum static current of 2µA. Packaged in a 20-TSSOP surface-mount configuration, it functions reliably across a temperature range of -40°C to +85°C.

Feature Summary

• VHCT technology ensures TTL-compatible input logic levels while maintaining CMOS performance characteristics.
• Octal architecture integrates eight independent D-type flip-flops with positive-edge triggering into a single unit.
• Three-state outputs allow direct connection to bus systems via an active-low output enable control signal.

Applications

• Registering data on microprocessor buses
• Shift register implementations
• Bus-oriented memory storage applications

Procurement Notes

Verify the specific suffix 'ATTR' against the manufacturer's official documentation to confirm package type and tape/reel specifications. Confirm RoHS compliance status and moisture sensitivity level ratings prior to integration. Ensure the selected variant matches the required operating temperature range and pinout compatibility for the target PCB layout design.

Selection Notes

Select this component when TTL-level interface compatibility is required alongside high-speed CMOS operation. The VHCT series bridges standard 5V logic families, making it suitable for mixed-voltage environments. Consider the 20-TSSOP package dimensions for space-constrained designs requiring surface-mount assembly techniques.

Part Context

This part belongs to the 74VHCT family, designed to combine the speed of CMOS with the noise immunity and drive capability of TTL inputs. It serves as a digital storage element within larger logic circuits, providing reliable data retention and transfer capabilities for synchronous digital systems.

Replacement Considerations

Direct substitutes include SN74VHCT574DWR from Texas Instruments and MC74VHCT574ADTR2G from onsemi. Verify pinout compatibility and electrical parameter alignment before substitution.

FAQ

What is the function of the Output Enable (OE) pin?

The OE pin controls the state of the outputs. When OE is low, outputs are active; when high, outputs enter a high-impedance state.

How does VHCT technology differ from standard HC logic?

VHCT uses Schmitt-trigger inputs that accept TTL logic levels, whereas standard HC logic requires CMOS-compatible input voltages.