HEF4021BP-Q100U

Shift Registers Overview

The HEF4021BP-Q100U is an 8-bit static shift register from the Nexperia HEF4021B-Q100 family, designed for parallel-to-serial conversion. It features a synchronous serial data input (DS), clock input (CP), and asynchronous active HIGH parallel load input (PL). The device includes eight asynchronous 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. It operates within a recommended VDD power supply range of 3 V to 15 V referenced to VSS.

Shift Registers Feature Summary

• Automotive product qualification in accordance with AEC-Q100 Grade 1 standard
• Schmitt trigger action on the clock input for tolerance of slower rise and fall times
• High noise immunity and CMOS low power dissipation characteristics
• Fully static operation with standardized symmetrical output characteristics

Shift Registers Applications

• Suitable for use in automotive applications as per AEC-Q100 qualification
• Parallel-to-serial data conversion tasks
• Digital signal processing requiring shift register functionality

Shift Registers Procurement Notes

Verify that the specific ordering suffix matches the required package type, as the HEF4021B-Q100 family includes multiple variants such as SO16 and TSSOP16. Confirm temperature range specifications align with application requirements, noting options for -40 °C to +85 °C and -40 °C to +125 °C. Ensure compliance with JEDEC standards and ESD protection levels specified in the datasheet before finalizing procurement.

Shift Registers Selection Notes

Select this component when an 8-bit shift register with automotive qualification is required. Consider the buffered parallel outputs available only on the last three stages if parallel readout is necessary. Evaluate the wide supply voltage range and Schmitt trigger clock input benefits for noisy environments or slow signal transitions. Verify package availability against board layout constraints.

Shift Registers Part Context

This part belongs to the Nexperia HEF4021B-Q100 series of 8-bit static shift registers. The family includes various package options like SO16 and TSSOP16, all sharing the same core logic function. The Q100 designation indicates automotive grade qualification. The HEF4021BP variant specifically refers to the PDIP package version, though current documentation focuses on surface mount packages.

Shift Registers Replacement Considerations

HEF4021BT-Q100 (SO16 package)

Shift Registers FAQ

How does the parallel load input affect data shifting?

When the PL input is HIGH, information on D0 to D7 is asynchronously loaded into the register independent of the clock. When PL is LOW, data on the DS input is shifted into the first register position on the clock transition.

What is the function of the SD and CD inputs?

Each register stage includes a set direct (SD) and clear direct (CD) input, allowing for direct control over the state of individual flip-flops within the shift register.