STMicroelectronics HCF4020BEY

Overview

HCF4020BEY from STMicroelectronics is a 14-stage ripple-carry binary counter IC in 16-pin DIP package, featuring buffered inputs/outputs, common asynchronous reset, Schmitt-trigger clock input (enabling unlimited rise/fall times), and operation up to 16 MHz (typ.) at VDD = 10 V. It advances on negative clock transitions and resets all outputs to logic low.

For engineers reviewing the HCF4020BEY datasheet, HCF4020BEY pinout, HCF4020BEY application, or HCF4020BEY equivalent, key selection considerations include its 14-bit divide-by-16384 capability, wide supply range (3–20 V), static operation, symmetrical output drive (±1.36 mA at 5 V), and industrial temperature support (–55°C to +125°C).

Technical Context

The HCF4020BEY implements a cascaded chain of 14 master-slave flip-flops with asynchronous active-high RESET, enabling precise frequency division without internal synchronization overhead. Its Schmitt-trigger input ensures robust noise immunity and eliminates external conditioning for slow or noisy clock sources.

Each stage propagates on the falling edge of the preceding stage's output, resulting in cumulative propagation delay - e.g., 130 ns max (Q1→Q14 at VDD = 15 V). Output buffering delivers standardized VOH/VOL (e.g., VOH ≥ 4.95 V at VDD = 5 V) and supports fan-out into CMOS or TTL loads.

Key Specifications

Pinout & Package

Package: Plastic DIP-16 (0.300" width), 16-pin through-hole dual in-line package per mechanical drawing P001C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD4020BE and MC14020BDR2G, the HCF4020BEY offers the widest operating temperature range, strictest input leakage guarantee, and factory-verified quiescent current - making it optimal for mission-critical timing in harsh environments where long-term reliability trumps marginal speed gains.

Availability

HCF4020BEY is available at Aetrix Electronics and suitable for frequency division in signal generators, digital timing control in industrial PLCs, power-up sequence control, and legacy system clock scaling requiring stable component supply across extended temperature and voltage ranges.

Supply support for HCF4020BEY 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The HCF4020BEY belongs to ST's legacy HCMOS logic family, engineered for robustness in industrial control and instrumentation where wide supply tolerance, noise immunity, and long-lifecycle availability are essential.

FAQ

Can HCF4020BEY operate from a 3.3 V supply?

Yes - the HCF4020BEY is fully specified from 3 V to 20 V. At 3.3 V, it delivers VOH ≥ 3.25 V and VOL ≤ 0.05 V, with fMAX ≈ 2.5 MHz (typ.). Output drive drops to ±0.3 mA, sufficient for CMOS loads but marginal for direct TTL interfacing without level-shifting.

What is the purpose of the Schmitt-trigger input on pin 10?

The Schmitt-trigger input on Φ (pin 10) provides hysteresis (≈1.5 V at VDD = 5 V), enabling reliable clocking from slow-rising signals (e.g., RC oscillators, mechanical switch debouncing, or noisy sensor outputs) without external conditioning circuitry or risk of metastability.

Does HCF4020BEY support synchronous reset?

No - HCF4020BEY implements only asynchronous (level-sensitive) reset via pin 11. The reset takes effect immediately upon assertion, overriding any clock edge. Synchronous reset requires external gating of the clock or use of a different counter family such as the HCF4040B with added control logic.

How does propagation delay accumulate across all 14 stages?

Delay accumulates linearly: t_PHL(Q1→Q14) ≈ 13 × t_PHL(Qn→Qn+1). At VDD = 15 V, max per-stage delay is 60 ns, so worst-case total delay from Φ to Q14 is ~780 ns. This defines the minimum time between consecutive valid Q14 transitions and constrains maximum usable input frequency in cascaded configurations.