Renesas X28HC256PIZ-90

Overview

X28HC256PIZ-90 from Intersil is a 256 kbit (32k × 8), 5V-only, byte-alterable EEPROM in 28-pin PDIP package, featuring 90 ns access time, -40°C to +85°C industrial temperature range, and RoHS-compliant construction. It delivers high-reliability nonvolatile storage for firmware configuration, calibration data, and system parameter retention in embedded controllers and industrial PLCs.

For engineers reviewing the X28HC256PIZ-90 datasheet, X28HC256PIZ-90 pinout, X28HC256PIZ-90 application, or X28HC256PIZ-90 equivalent, key selection considerations include its 100,000 write-cycle endurance, 100-year data retention, page-write capability (128-byte bursts), DATA/Toggle-bit polling support, and JEDEC software data protection compliance.

Technical Context

The X28HC256PIZ-90 implements a CMOS-based Direct Write™ floating-gate EEPROM cell architecture with textured poly technology, enabling single 5V supply operation without external high-voltage programming circuits. Its control logic supports dual-line chip enable (CE) and output enable (OE) for bus contention avoidance in multi-device memory arrays.

It features two independent early-write-detection mechanisms: DATA polling on I/O7 (complement read during programming) and Toggle-bit polling on I/O6 (state alternation until completion). Page write mode allows up to 128 consecutive bytes to be loaded before internal auto-programming begins, with ≤100 µs inter-byte timing window.

Key Specifications

Pinout & Package

Package: 28-pin Plastic Dual In-line Package (PDIP), RoHS-compliant, 0.6-inch width, E28.6 drawing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT28C256-15PU and MX28LV256APCI-12, the X28HC256PIZ-90 provides faster 90 ns access, integrated Toggle-bit polling for tighter timing control, and JEDEC-standard software protection-making it optimal for real-time industrial systems requiring deterministic write completion and robust power-cycle immunity.

Availability

X28HC256PIZ-90 is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, telecom base station firmware backup, and automotive body control modules requiring stable component supply across extended product lifecycles.

Supply support for X28HC256PIZ-90 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 is a leading provider of precision analog and power management solutions, serving industrial, infrastructure, and high-end consumer markets with high-reliability semiconductor products.

The X28HC256 product line was designed specifically for robust, 5V-compatible nonvolatile storage in mission-critical embedded systems where long-term data integrity, deterministic write timing, and industrial temperature operation are mandatory.

FAQ

What is the maximum operating temperature range for the X28HC256PIZ-90?

The X28HC256PIZ-90 is rated for industrial operation from -40°C to +85°C. This specification is explicitly confirmed in the Ordering Information table on page 2 of FN8108 Rev 5.00, where "X28HC256PIZ-90" is listed with "-40 to +85" under Temperature Range. The device maintains full functionality-including 90 ns access time and valid write timing-across this entire range.

Does the X28HC256PIZ-90 require external high-voltage programming circuitry?

No, the X28HC256PIZ-90 operates from a single 5V supply and requires no external high-voltage programming circuitry. As stated on page 1 of FN8108 Rev 5.00, it is a "5V only nonvolatile memory" with "no external high voltages or VP-P control circuits." Its Direct Write™ cell technology enables self-timed internal programming using only VCC.

How does the page write function work on the X28HC256PIZ-90?

The X28HC256PIZ-90 supports 128-byte page writes: up to 128 consecutive bytes can be loaded within ≤100 µs intervals before the internal programming cycle starts. Per page 10 of FN8108 Rev 5.00, A7–A14 must remain constant during the sequence, and the full 256 kbit memory can be rewritten in typically 0.8 seconds-significantly faster than sequential byte writes.

What are the two methods of early write detection supported by the X28HC256PIZ-90?

The X28HC256PIZ-90 supports DATA polling on I/O7 and Toggle-bit polling on I/O6, as detailed on pages 1 and 10 of FN8108 Rev 5.00. During programming, I/O7 returns the complement of the last written byte; I/O6 toggles state on successive reads. Both methods eliminate fixed delay loops and enable precise software synchronization with write completion.

Is the X28HC256PIZ-90 RoHS compliant and what package type does it use?

Yes, the X28HC256PIZ-90 is RoHS compliant and uses a 28-pin Plastic Dual In-line Package (PDIP), as confirmed in the Ordering Information table (page 2) and Pin Configurations diagram (page 3) of FN8108 Rev 5.00. The "Z" suffix denotes RoHS-compliant packaging, and the "PI" prefix specifies the PDIP variant with industrial temperature grade.