Nexperia USA Inc. HEF4557BT,653

Overview

HEF4557BT,653 from Nexperia is a static 1-to-64-bit programmable-length serial shift register with dual data inputs (DA/DB), asynchronous master reset (MR), and dual-edge clocking via CP0/CP1. It operates from 3 V to 15 V over −40 °C to +85 °C and supports recirculation via A/B select - used in industrial control sequencers, legacy bus interface logic, and configurable timing delay lines.

For engineers reviewing the HEF4557BT,653 datasheet, HEF4557BT,653 pinout, HEF4557BT,653 application, or HEF4557BT,653 equivalent, key selection criteria include variable bit-length programming (1–64 bits via L1–L32), dual-clock edge sensitivity (CP0↑/CP1↓ or CP0↓/CP1↑), guaranteed operation at 15 V, and SO16 package compatibility with legacy 4000-series PCB footprints.

Technical Context

The HEF4557BT,653 implements a fully static CMOS shift register architecture with asynchronous MR overriding all clock and data activity. Its length is set by binary-weighted inputs L1 (1), L2 (2), L4 (4), L8 (8), L16 (16), and L32 (32), summing to register length + 1 - enabling precise 1–64-bit configurations without external logic.

It uses dual-clock phase control: data shifts right on CP0 rising edge while CP1 is LOW, or on CP1 falling edge while CP0 is HIGH. Output buffering provides symmetrical VOH/VOL (≤0.05 V low, ≥4.95 V high at 5 V) and rail-to-rail drive capability across its full 3–15 V supply range.

Key Specifications

Pinout & Package

HEF4557BT,653 is housed in a plastic small outline package (SO16, SOT109-1) with 16 leads and 3.9 mm body width - compatible with standard SOIC-16 footprints and reflow soldering profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar programmable shift register applications.

Compared with CD4015BE and 74HC595, the HEF4557BT,653 uniquely delivers field-programmable bit length (1–64), dual-edge clocking, and 15 V operation - making it irreplaceable in legacy industrial timing, high-voltage bus adaptation, and deterministic delay-line designs where flexibility and voltage headroom are mandatory.

Availability

HEF4557BT,653 is available at Aetrix Electronics and suitable for industrial sequence controllers, legacy bus interface adapters, configurable delay lines, and test equipment pattern generators requiring stable component supply across extended temperature and voltage ranges.

Supply support for HEF4557BT,653 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Nexperia is a global semiconductor expert focused on essential efficiency-enhancing components - delivering high-performance, reliable, and scalable logic, discrete, and MOSFET solutions.

The HEF4557BT,653 belongs to Nexperia's legacy 4000B-series logic family, engineered for backward compatibility, wide supply voltage operation (3–15 V), and robust performance in industrial control, instrumentation, and retrofit applications.

FAQ

What is the minimum clock pulse width required for reliable operation at 15 V?

At 15 V, the minimum CP0 LOW pulse width and CP1 HIGH pulse width are both 40 ns, and the minimum MR HIGH pulse width is 50 ns. These values ensure proper internal state capture and avoid metastability in the static CMOS latch structure, as verified in Table 8 of the Rev. 7 datasheet.

How does the A/B select input affect data flow during shifting?

When A/B = LOW, DA is selected as the serial input feeding the first register stage; when A/B = HIGH, DB is selected instead. This allows dynamic switching between two independent data streams - essential for recirculation (e.g., connecting Q to DB) or multiplexed input routing without external gates.

Can unused length control inputs (e.g., L32 when configuring <33 bits) be left floating?

No. All unused inputs - including L1–L32, A/B, DA, DB, CP0, and CP1 - must be tied to VDD, VSS, or a defined logic level. Floating inputs risk increased supply current, erratic shifting behavior, or latch-up due to CMOS input stage instability, per Section 1 of the datasheet.

What is the maximum achievable shift rate at 10 V supply?

At 10 V, the maximum clock frequency is 14 MHz (typical) with CL = 50 pF, corresponding to a minimum clock period of ~71 ns. This is derived from fmax in Table 8 and accounts for propagation delay (90 ns typ), transition time (30 ns typ), and setup/hold margins under recommended operating conditions.