Renesas X28HC256JIZ-12

Overview

X28HC256JIZ-12 from Intersil is a 256 kbit (32k × 8), 5V-only, byte-alterable CMOS EEPROM with 120 ns access time, industrial temperature range (–40°C to +85°C), and 32-lead PLCC RoHS-compliant package. It features 128-byte page write capability, DATA polling and Toggle bit early write completion detection, and JEDEC-standard software data protection for robust nonvolatile storage in embedded control systems.

For engineers reviewing the X28HC256JIZ-12 datasheet, X28HC256JIZ-12 pinout, X28HC256JIZ-12 application, or X28HC256JIZ-12 equivalent, key selection criteria include industrial-grade reliability, 100,000 write cycles, 100-year data retention, 5V single-supply operation, and compatibility with legacy parallel memory interfaces requiring CE/OE/WE control.

Technical Context

The X28HC256JIZ-12 implements a parallel-addressed, asynchronous EEPROM architecture with dual-line chip enable (CE) and output enable (OE) control to eliminate bus contention. Its Direct Write™ floating-gate cell technology enables self-timed byte and page writes without external high-voltage programming circuits or pre-erase cycles.

It supports two hardware write-inhibit mechanisms-VCC sense (inhibits below ~3.5 V) and signal-level gating (via CE high, OE low, or WE high)-and integrates JEDEC-compliant software data protection activated via a three-byte unlock sequence to A5555H/A2AAAH/A5555H, ensuring immunity to power-up/down corruption.

Key Specifications

Pinout & Package

Package: 32-lead Plastic Leaded Chip Carrier (PLCC), RoHS-compliant, dimensions 12.57 mm × 15.11 mm × 3.55 mm (N32.45x55).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT28C256-15JI, X28HC256JIZ-12 delivers faster 120 ns access and Toggle bit polling for reduced software overhead; versus MX28LV256APCI-12, it avoids 3.3 V/5 V interface ambiguity in legacy 5 V-only systems while maintaining identical speed and endurance.

Availability

X28HC256JIZ-12 is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, automotive body control modules, and telecom line cards requiring stable component supply across extended product lifecycles.

Supply support for X28HC256JIZ-12 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 pioneer in high-reliability analog and nonvolatile memory solutions, specializing in power management and precision timing for industrial and infrastructure markets.

The X28HC256 product line was engineered for robust, 5V parallel EEPROM replacement in legacy embedded systems-emphasizing drop-in compatibility, industrial temperature resilience, and simplified software-controlled write protection.

FAQ

What is the maximum operating temperature range for the X28HC256JIZ-12?

The X28HC256JIZ-12 is rated for industrial operation from –40°C to +85°C. This range is validated per the datasheet's Recommended Operating Conditions and supported by thermal characterization across the full PLCC package. The "I" suffix in the part number explicitly denotes industrial temperature qualification, distinguishing it from commercial-grade variants like X28HC256JZ-12 (0°C to +70°C). Operation outside this range may compromise write endurance or data retention.

Does the X28HC256JIZ-12 require external high-voltage programming circuitry?

No, the X28HC256JIZ-12 operates with a single 5 V supply and requires no external high-voltage programming circuitry. Its proprietary textured poly floating-gate technology enables "Direct Write™" functionality-allowing byte and page writes using only standard TTL/CMOS logic levels on CE, OE, and WE. All internal programming voltages are generated on-chip, eliminating the need for VP-P generators or complex timing controllers typically found in older EEPROM families.

How does software data protection work on the X28HC256JIZ-12?

Software data protection on the X28HC256JIZ-12 is enabled via a nonvolatile three-byte unlock sequence written to addresses 5555H, 2AAAH, and 5555H with data values AAH, 55H, and A0H respectively. Once set, the device remains write-protected across power cycles until the six-step reset sequence is executed. This feature prevents inadvertent writes during power-up/down transients and is fully implemented within the X28HC256JIZ-12 silicon-no external hardware is required.

Can the X28HC256JIZ-12 be used in place of the X28HC256JI-12?

Yes, the X28HC256JIZ-12 is a direct replacement for the X28HC256JI-12. Both share identical electrical specifications, timing (120 ns access), industrial temperature range (–40°C to +85°C), and 32-lead PLCC packaging. The "Z" suffix in X28HC256JIZ-12 explicitly indicates RoHS compliance, whereas X28HC256JI-12 lacks this designation. For new designs or RoHS-mandated programs, X28HC256JIZ-12 is the preferred variant; legacy boards designed for X28HC256JI-12 can accept X28HC256JIZ-12 without modification.

What is the typical full-memory rewrite time for the X28HC256JIZ-12 using page write?

The X28HC256JIZ-12 supports 128-byte page writes, enabling the entire 256 kbit memory to be rewritten in typically less than 0.8 seconds. This performance is achieved by loading up to 128 consecutive bytes into the internal latch before initiating the self-timed programming cycle. Each byte load must occur within 100 µs of the prior WE falling edge; once the page is loaded, the internal write completes automatically. Actual time depends on system bus speed and polling method but remains consistently sub-second under nominal conditions.