STMicroelectronics HCF4017BEY

Overview

HCF4017BEY from STMicroelectronics is a B-series CMOS 5-stage Johnson decade counter with 10 decoded outputs, operating up to 10 MHz (typ.) at VDD = 10 V, featuring Schmitt-trigger clock input, ripple-capable CARRY-OUT, and fully static operation across 3–20 V supply. It advances on positive clock edges when CLOCK INHIBIT is low, resets synchronously via high-level RESET, and delivers spike-free, single-cycle-high decoded outputs-used in LED chasers, sequential timing control, and divide-by-N counters.

For engineers reviewing the HCF4017BEY datasheet, HCF4017BEY pinout, HCF4017BEY application, or HCF4017BEY equivalent, key selection factors include decoded output timing accuracy, VDD-dependent propagation delay (e.g., 85 ns typ. at 15 V), quiescent current stability up to 20 V, and DIP-16 package compatibility with legacy through-hole PCB layouts.

Technical Context

The HCF4017BEY implements a synchronous Johnson counter architecture with anti-lock gating to guarantee deterministic state transitions and prevent illegal states. Its Schmitt-trigger clock input accepts unlimited rise/fall times, enabling robust interfacing with slow or noisy clock sources.

Each of the ten decoded outputs (Q0–Q9) asserts high for exactly one full clock cycle, while CARRY-OUT toggles every 10 clocks-supporting cascaded counting without external logic. Reset is asynchronous but internally synchronized to avoid metastability-induced glitches.

Key Specifications

Pinout & Package

Package: Plastic DIP-16 (0.300″ width), JEDEC MS-001, 200 mil pitch, lead material SnPb (legacy) or Pb-free per RoHS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD4017BE and MC14017BCP, the HCF4017BEY offers superior speed (10 MHz vs. ≤5 MHz), tighter propagation delay control, and verified 20 V operation-making it optimal for high-reliability industrial sequencers requiring extended voltage headroom and precise timing.

Availability

HCF4017BEY is available at Aetrix Electronics and suitable for LED chaser designs, industrial timer modules, divide-by-N counters, and reset-synchronized state machines requiring stable component supply across extended temperature and voltage ranges.

Supply support for HCF4017BEY 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, Switzerland, specializing in automotive, industrial, and power management ICs with strong analog and mixed-signal heritage.

The HCF4017B belongs to ST's legacy B-series CMOS logic family, designed specifically for robust, low-power, wide-supply-voltage digital sequencing in harsh environments-prioritizing reliability over raw speed.

FAQ

Can HCF4017BEY operate reliably at 20 V supply?

Yes. The datasheet specifies absolute maximum VDD = +22 V and recommends operation up to 20 V. Quiescent current is characterized at 20 V (3000 µA max), and output voltage levels remain valid across the full 3–20 V range-making it suitable for unregulated 18–24 V industrial rails with appropriate decoupling.

Is the CARRY-OUT signal synchronized to Q9 or to the clock?

CARRY-OUT is synchronized to the Q9-to-Q0 transition and occurs on the same clock edge that causes Q9 to go low and Q0 to go high. Its propagation delay (80 ns typ. at 15 V) matches decoded outputs, ensuring deterministic ripple-clocking of cascaded counters without added setup constraints.

What happens if CLOCK INHIBIT is held high during RESET assertion?

The counter resets to Q0 = H regardless of CLOCK INHIBIT state. RESET is asynchronous and overrides inhibit functionality-ensuring guaranteed zero-state initialization even during paused operation, which is essential for safety-critical startup sequences.

Does HCF4017BEY require external pull-up resistors on decoded outputs?

No. Outputs are push-pull CMOS with VOH ≥ 4.95 V and VOL ≤ 0.05 V at VDD = 5 V, capable of directly driving TTL loads or LEDs. Pull-ups are unnecessary unless interfacing with open-drain buses or implementing wired-OR logic-both outside standard use cases.