Nexperia USA Inc. HEF4520BT,653

Overview

HEF4520BT,653 from Nexperia is a dual 4-bit internally synchronous binary counter IC with two independent clock inputs (nCP0 and nCP1), buffered Q0–Q3 outputs per counter, and asynchronous master reset (nMR). It operates across 3.0 V to 15.0 V supply, supports dual-edge clocking (LOW-to-HIGH on nCP0 when nCP1 = HIGH; HIGH-to-LOW on nCP1 when nCP0 = LOW), and delivers propagation delays as low as 17 ns at 15 V. Used in digital timing control, frequency division, and state sequencing circuits in industrial control panels and instrumentation.

For engineers reviewing the HEF4520BT,653 datasheet, HEF4520BT,653 pinout, HEF4520BT,653 application, or HEF4520BT,653 equivalent, this page provides verified functional behavior, SO16 package layout, static/dynamic electrical specifications, real-world use cases, and validated alternative parts for design continuity and sourcing flexibility.

Technical Context

The HEF4520BT,653 implements two independent 4-bit binary counters sharing no internal coupling-each with dedicated clock inputs (1CP0/1CP1 and 2CP0/2CP1), reset (1MR/2MR), and outputs (1Q0–1Q3 and 2Q0–2Q3). Clock selection logic enables either input to serve as active clock while the other acts as enable, supporting flexible edge-triggered sequencing without external gating.

Its CMOS architecture ensures full static operation, wide voltage tolerance (3–15 V), and high noise immunity. Input clamp diodes allow safe interfacing to voltages exceeding VDD when used with current-limiting resistors, and ESD protection meets HBM >2000 V and CDM >1000 V per JEDEC JS-001/JS-002.

Key Specifications

Pinout & Package

HEF4520BT,653 is housed in a plastic small outline package (SO16), SOT109-1, with 16 leads, 3.9 mm body width, and standard 1.27 mm lead pitch. Pin 1 is marked by a notch or dot; pin numbering follows counterclockwise convention from top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual binary counter applications.

Compared with CD4020BE and 74HC4040PW, HEF4520BT,653 uniquely delivers dual independent 4-bit synchronous counting, 3–15 V operation, and selectable edge-triggering - making it irreplaceable for compact, voltage-flexible, multi-timing applications where channel isolation and deterministic reset are mandatory.

Availability

HEF4520BT,653 is available at Aetrix Electronics and suitable for industrial timer modules, frequency divider circuits, legacy system clock generation, and power-up sequencing controllers requiring stable component supply across extended temperature and voltage ranges.

Supply support for HEF4520BT,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 delivering high-performance, reliable discrete, logic, and MOSFET solutions with focus on efficiency, reliability, and sustainability.

The HEF4520BT,653 belongs to Nexperia's legacy logic family designed for industrial-grade digital timing, offering wide supply range, robust ESD protection, and long-lifecycle availability for mission-critical embedded systems.

FAQ

What clock edge does HEF4520BT,653 respond to on pin 1 (1CP0)?

Pin 1 (1CP0) responds to the LOW-to-HIGH transition - but only when pin 2 (1CP1) is held HIGH. This dual-input logic prevents unintended counting during power-up or noise events, enabling precise edge selection without external logic.

Can HEF4520BT,653 operate reliably at 3.3 V?

Yes - the device is fully specified from 3.0 V to 15.0 V. At 3.3 V, VIH = 2.31 V and VIL = 0.99 V (per extrapolated static characteristics), providing >1.3 V noise margin. Propagation delay increases to ~110 ns, supporting up to ~9 MHz operation with 50 pF load.

Is the reset function synchronous or asynchronous?

The master reset (pins 7 and 15) is asynchronous and active-HIGH. A HIGH signal forces all Q outputs LOW immediately, independent of clock edges or internal state - essential for fail-safe initialization and emergency halt functions.

Does HEF4520BT,653 require external pull-up or pull-down resistors on unused clock inputs?

No - unused clock inputs (e.g., 1CP1 when using only 1CP0) should be tied HIGH or LOW per functional intent, not left floating. The datasheet confirms internal input protection but specifies no internal pull resistors; floating inputs risk metastability and increased ICC.