HEF4021BT,653

Shift Registers Overview

The HEF4021BT,653 is an 8-bit static shift register and parallel-to-serial converter manufactured by Nexperia. It features a synchronous serial data input (DS), clock input (CP), asynchronous active HIGH parallel load input (PL), eight parallel data inputs (D0 to D7), and buffered parallel outputs from the last three stages (Q5 to Q7). Each stage utilizes a D-type master-slave flip-flop with set direct (SD) and clear direct (CD) inputs. The device operates within a recommended supply voltage range of 3 V to 15 V referenced to VSS. It is specified for ambient temperatures from -40 °C to +125 °C.

Shift Registers Feature Summary

• CMOS low power dissipation with high noise immunity
• Fully static operation tolerant of slower rise and fall times
• ESD protection exceeding 2000 V (HBM) and 1000 V (CDM)
• Complies with JEDEC standard JESD 13-B

Shift Registers Applications

• Parallel-to-serial data conversion
• Industrial control systems
• Digital signal processing interfaces

Shift Registers Procurement Notes

Verify the specific ordering suffix matches the required package type. The HEF4021BT,653 designation corresponds to the SO16 plastic small outline package (SOT109-1). Confirm temperature range requirements align with the -40 °C to +125 °C specification before finalizing procurement orders.

Shift Registers Selection Notes

Select this component when an 8-bit shift register with buffered parallel outputs is required. Ensure the application voltage falls within the 3 V to 15 V range. Consider the SO16 package dimensions if board space is constrained. Verify that the Schmitt trigger action on the clock input meets the system's tolerance for slow signal transitions.

Shift Registers Part Context

This part belongs to the HEF4021B series of 8-bit static shift registers. It is part of the broader HEF4000B logic family, which provides standardized symmetrical output characteristics. The device is designed for general-purpose digital logic applications requiring reliable data shifting and storage capabilities in industrial environments.

Shift Registers Replacement Considerations

The HEF4021BTT,653 serves as a pin-compatible alternative utilizing the TSSOP16 package (SOT403-1). Both variants share identical electrical specifications and functionality but differ in physical footprint and body width.