HEF4557BP,652

Shift Registers Overview

The HEF4557BP,652 is a static clocked serial shift register from the HEF4000B logic family. It features a variable length configuration ranging from 1 to 64 bits, determined by six length control inputs (L1, L2, L4, L8, L16, L32). The device supports dual data inputs (DA and DB) selectable via an A/B input for recirculation purposes. It operates on a recommended supply voltage range of 3 V to 15 V referenced to VSS. Propagation delays vary with load capacitance; typical values at 15 V are 65 ns for clock-to-Q transitions and 55 ns for master reset recovery.

Shift Registers Feature Summary

• Fully static operation allows indefinite data retention without clocking.
• Programmable bit length from 1 to 64 bits using binary-weighted control inputs.
• Dual data input selection enables flexible recirculation configurations.
• Complementary buffered outputs provide both true and inverted signals.

Shift Registers Applications

• Variable-length delay line circuits
• Recirculating memory buffers
• Serial-to-serial data shifting applications

Shift Registers Procurement Notes

Verify the package designation matches the required form factor, as the HEF4557B series includes SO16 surface-mount variants. Confirm that the specific ordering suffix corresponds to the intended packaging style. Ensure design compliance with the specified operating temperature range and supply voltage limits to maintain functional integrity.

Shift Registers Selection Notes

Select this component when a programmable shift register length is required within the HEF4000B CMOS logic family. Consider the dual data input capability if recirculation or alternative data source switching is necessary. Verify that the available propagation delays meet the timing requirements of the target clock frequency and load conditions.

Shift Registers Part Context

The HEF4557B belongs to the HEF4000B series of CMOS logic integrated circuits manufactured by Nexperia. This series is standardized under JEDEC JESD 13-B specifications. The device utilizes LOCMOS technology, offering symmetrical output characteristics and compatibility with standard digital logic interfaces across industrial temperature ranges.

Shift Registers Replacement Considerations

Public documentation indicates the HEF4557BP variant was removed in revision 7 of the datasheet. Designers should verify current availability and consider equivalent parts from the same HEF4000B family or compatible manufacturers offering similar variable-length shift register functionality.