STMicroelectronics HCF4541BEY

Overview

HCF4541BEY from STMicroelectronics is a programmable 16-stage binary counter/timer IC with built-in RC oscillator, operating as either a 2^N frequency divider (N = 8, 10, 13, or 16) or single-transition timer. It features Q/Q output selection, MODE-controlled operation (recycle vs. one-shot), and auto/master reset for power-efficient startup. Used in precision timing circuits requiring stable low-frequency division (DC–100 kHz) with TTL/HTL load drive capability.

For engineers reviewing the HCF4541BEY datasheet, HCF4541BEY pinout, HCF4541BEY application, or HCF4541BEY equivalent, this device supports programmable timing intervals via external R-C network, offers logic-level flexible output (Q or Q), operates across 3–20 V supply, delivers <100 Ω output resistance at 15 V, and drives up to six low-power TTL loads over –55°C to +125°C.

Technical Context

The HCF4541BEY integrates a 16-bit ripple counter, on-chip RC oscillator (f = 1/(2.3·R_TC·C_TC)), automatic power-on reset, and output control logic. Counter advances on positive clock edge; reset clears all stages and disables oscillator during active reset to minimize quiescent current.

Mode selection (pin 10) determines functional behavior: logic "1" enables continuous square-wave division; logic "0" enables single-transition timing with retriggerable one-shot output. Time select inputs A/B (pins 12/13) configure division ratio (256 to 65536), while Q/Q select (pin 9) sets initial output polarity after reset.

Key Specifications

Pinout & Package

Package: 14-pin plastic DIP (Dual In-line Package), JEDEC MS-001, body width 7.1 mm, lead pitch 2.54 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD4541BE and 74HC4060, the HCF4541BEY provides unique integration of programmable division, retriggerable one-shot mode, and output polarity control in a single 14-pin package - reducing board space and eliminating glue logic in timing-critical industrial controls.

Availability

HCF4541BEY is available at Aetrix Electronics and suitable for industrial timer relays, power supply soft-start controllers, legacy system watchdog timers, and low-power sensor wake-up circuits requiring stable component supply across extended temperature ranges.

Supply support for HCF4541BEY 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, designing and manufacturing analog, digital, and mixed-signal ICs for industrial, automotive, and power applications.

The HCF4541BEY belongs to ST's High-Speed CMOS (HCMOS) B-series logic family, engineered for reliable programmable timing in harsh environments - emphasizing low power, wide supply range, and robust noise immunity.

FAQ

What is the minimum external resistor value for the RC oscillator?

The datasheet specifies R_S > 10 kΩ for stable oscillator operation. Using a resistor below this threshold risks timing inaccuracy and increased sensitivity to voltage and temperature drift. Verified test data shows oscillation becomes unreliable below 9.5 kΩ at VDD = 15 V and T_A = 25°C, with duty cycle distortion exceeding 15%.

Can pin 3 be used simultaneously for RC timing and external clock input?

No - pin 3 serves a dual function but cannot perform both roles concurrently. When RTC/CTC pins (1,2) are connected, pin 3 acts as the RC oscillator resistor node. To use an external clock, disconnect the RC network and apply the clock signal directly to pin 3; the internal oscillator is automatically disabled.

How does AUTO RESET (pin 5) affect power consumption during startup?

When pin 5 is low, the auto-reset circuit remains active until the oscillator stabilizes, drawing ~600 µA peak current at VDD = 15 V. This transient lasts <100 ms. If low quiescent power is critical, disable auto-reset (pin 5 = high) and assert a clean MR pulse externally after power stabilization.

Is the HCF4541BEY compatible with 3.3 V logic systems?

Yes - the device operates down to 3 V supply, with verified VIH/VIL thresholds (e.g., VIH = 1.5 V min. at VDD = 5 V, scaling linearly). However, output drive strength drops significantly below 5 V; at 3.3 V, it reliably drives only one LP-TTL load, not six. Use level-shifting or buffer stages if interfacing with standard 5 V TTL.