74AC74B

Overview

The STMicroelectronics 74AC74B is a dual D-type positive edge-triggered flip-flop featuring asynchronous preset and clear inputs. It operates within a supply voltage range of 2V to 6V, supporting CMOS logic levels. The device provides complementary Q and Q outputs with source/sink capabilities of 24mA. Key electrical parameters include a maximum propagation delay of 9.5ns at 5V with 50pF load, a clock frequency of 270MHz, and a static current of 4µA. It functions across an industrial temperature range of -55°C to +125°C.

Feature Summary

• Dual D-type flip-flop architecture with positive edge triggering
• Asynchronous preset and clear control inputs independent of clock
• High-speed CMOS technology for reduced power consumption
• Complementary outputs with high drive capability

Applications

• Parallel data storage in digital systems
• Shift register construction
• Timing and synchronization circuits
• Bus interface applications requiring state retention

Procurement Notes

Verify the specific suffix 'B' against the manufacturer's latest datasheet to confirm package type and RoHS compliance status. Confirm availability as legacy or active status may vary by region. Ensure the selected variant matches the required operating temperature range and voltage specifications for the target application environment before finalizing procurement.

Selection Notes

Select this component when dual independent D-type storage with asynchronous control is required. Consider the 2V-6V operating range for compatibility with various logic families. Evaluate the 24mA output drive strength against load requirements. Compare propagation delays and clock frequencies against system timing constraints to ensure signal integrity.

Part Context

The 74AC74B belongs to the 74AC series of high-speed CMOS logic devices from STMicroelectronics. This series is designed for applications requiring faster switching speeds than standard 74LS counterparts while maintaining lower power consumption. The device is part of a broader family of logic ICs including buffers, gates, and other flip-flops, standardized for widespread industrial use.

Replacement Considerations

Cross-reference with equivalent parts such as SN74AC74 or MC74AC74 from other manufacturers. Verify pinout compatibility and logical function equivalence. Check if alternative packages (e.g., SOIC vs TSSOP) are available from substitute suppliers if the original package is discontinued.