Renesas IS82C54Z

Overview

IS82C54Z from Intersil is a CMOS programmable interval timer IC with three independent 16-bit counters, 8MHz clock input capability, TTL-compatible I/O, and operation over –40°C to +85°C. It serves as a system timing peripheral in legacy x86 embedded controllers for real-time clock generation, event counting, and programmable rate control.

For engineers reviewing the IS82C54Z datasheet, IS82C54Z pinout, IS82C54Z application, or IS82C54Z equivalent, this page delivers verified functional identity, validated PDIP-24 pin mapping, confirmed -40°C to +85°C industrial temperature rating, exact AC/DC electrical specs per FN2970 Rev 6.00, and two documented alternative parts with mode-level compatibility and package-aware selection guidance.

Technical Context

The IS82C54Z implements three fully independent 16-bit synchronous down counters, each configurable via software-written control words into one of six operational modes (Mode 0–5), supporting binary or BCD counting. Its read/write logic decodes A0/A1 address lines to select Counter 0/1/2 or the Control Word Register, with CS, RD, and WR enabling standard microprocessor bus interfacing.

It features a status read-back command that latches count value, output state, null-count flag, and programmed mode-enabling non-intrusive runtime monitoring. Static CMOS design ensures low ICCSB = 10µA standby current while maintaining full TTL compatibility and single +5V supply operation across its specified temperature range.

Key Specifications

Pinout & Package

IS82C54Z is housed in a 24-lead plastic dual in-line package (PDIP) with 0.6-inch body width and E24.6 mechanical drawing compliance. Pin 12 and Pin 24 are dedicated GND and VCC respectively; all digital I/O pins are TTL-compatible and three-state capable.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS82C54-10Z and Intel 8254-10, the IS82C54Z delivers optimal balance of industrial temperature operation, low-power CMOS performance, and diagnostic-ready status read-back-making it the preferred choice for new designs targeting long-lifecycle embedded systems.

Availability

IS82C54Z is available at Aetrix Electronics and suitable for industrial motor control, legacy x86 system timing, and programmable power sequencing requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for IS82C54Z 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

Intersil Corporation (now part of Renesas Electronics) is a semiconductor manufacturer specializing in precision analog, power management, and interface ICs for industrial, aerospace, and communications markets.

The IS82C54Z belongs to Intersil's legacy CMOS timer family, designed specifically to replace NMOS 8253/8254 in industrial and military-grade systems requiring low power, wide temperature operation, and enhanced diagnostics.

FAQ

What is the maximum clock frequency supported by the IS82C54Z?

The IS82C54Z supports a maximum clock input frequency of 8 MHz across all three counters. This specification is confirmed in the FN2970 Rev 6.00 datasheet under AC Electrical Specifications, where TCLK (Clock Period) is defined as 125 ns minimum for the base 82C54 variant. Higher-frequency variants (e.g., IS82C54-10Z) are separately rated but do not apply to the IS82C54Z.

Does the IS82C54Z support BCD counting mode?

Yes, the IS82C54Z supports Binary-Coded Decimal (BCD) counting when the BCD bit (D0) is set to 1 in the control word. In BCD mode, each counter operates as a 4-decade (0000–9999) timer, enabling direct decimal-based timing intervals such as 100 ms or 1 second without software conversion-fully documented in the Control Word Format section of FN2970 Rev 6.00.

What package type is used for the IS82C54Z?

The IS82C54Z is supplied in a 24-lead plastic dual in-line package (PDIP) with E24.6 mechanical drawing compliance. It features a Pb-free plus anneal finish per RoHS requirements, and is intended for through-hole wave solder processing-not reflow-as explicitly noted in the Ordering Information table on page 2 of FN2970 Rev 6.00.

Can the IS82C54Z operate with a 3.3V supply?

No, the IS82C54Z requires a +4.5 V to +5.5 V supply voltage and is not rated for 3.3 V operation. Its DC Electrical Specifications-including VIH, VOL, and ICCOP-are characterized exclusively at VCC = +5.0 V ±10%, and the device lacks 3.3 V logic level compatibility. Using 3.3 V will result in undefined behavior and potential failure to meet timing or drive specifications.

How does the status read-back command work in the IS82C54Z?

The IS82C54Z implements a dedicated status read-back command that latches the current output state (OUT), null-count flag, and programmed mode bits into an internal status register. When issued via the Control Word Register (A1=A0=11), it allows non-intrusive software interrogation of counter health and configuration-documented in detail on pages 9–10 of FN2970 Rev 6.00, including byte format and timing constraints.