74HCT109N,652

Overview

The 74HCT109N,652 is a dual positive-edge triggered JK flip-flop manufactured by NXP (now Nexperia) in the HCT logic series. It features individual J and K inputs, clock (CP) inputs, and asynchronous active-low set (SD) and reset (RD) inputs that operate independently of the clock. The device provides complementary Q and non-Q outputs. Packaged in a 16-pin PDIP format, it is specified for operation within a supply voltage range of 4.5 V to 5.5 V and an operating temperature range of -40 °C to +125 °C. It maintains pin compatibility with low power Schottky TTL.

Feature Summary

• Dual JK flip-flops with positive-edge triggering
• Asynchronous active-low set and reset inputs
• Schmitt-trigger action on clock input for noise tolerance
• Pin compatible with low power Schottky TTL

Applications

• Digital counting circuits
• Data storage registers
• Frequency division circuits
• State machine implementations

Procurement Notes

Verify the manufacturer designation carefully, as NXP's standard product business was rebranded to Nexperia. Ensure the datasheet references align with the specific part number suffix. Confirm RoHS compliance status through official documentation. Check for any updates regarding lead times or availability directly from authorized distributors.

Selection Notes

Select this component when dual JK flip-flops with HCT-level voltage compatibility are required. The HCT series ensures compatibility with 5 V TTL logic families. Consider the asynchronous control inputs for immediate state management. Verify package requirements against PCB layout constraints before finalizing the selection.

Part Context

This component belongs to the 74HCT family of high-speed CMOS logic devices. It is functionally equivalent to the 74HC109 but optimized for 5 V operation with TTL-compatible input thresholds. The 'N' indicates a plastic DIP package, and ',652' denotes the specific tape and reel or tube packaging configuration defined by the manufacturer.

Replacement Considerations

Direct substitutes include the 74HC109 for HC-series voltage levels and generic equivalents like SN74HCT109. Verify pinout compatibility and electrical specifications before substitution. Cross-reference with Nexperia's official replacement guide for confirmed alternatives.

FAQ

How do the set and reset inputs function?

The set (SD) and reset (RD) inputs are asynchronous and active-low. They force the output to a defined state regardless of the clock signal.

Can this device be used as a D-type flip-flop?

Yes, by tying the J and K inputs together, the JK flip-flop operates as a D-type flip-flop.

What is the purpose of the Schmitt trigger on the clock input?

The Schmitt trigger action makes the circuit highly tolerant to slower clock rise and fall times, reducing noise sensitivity.