Renesas X28HC64SZ-12

Overview

X28HC64SZ-12 from Intersil is a 64 kbit (8k × 8), 5V-only, byte-alterable EEPROM in 28-lead SOIC package, featuring 120 ns access time, 2 ms typical byte/page write cycle, and JEDEC-standard pinout compatible with industry RAMs. It supports DATA Polling and Toggle Bit end-of-write detection, software data protection, and operates across 0°C to +70°C for embedded control and configuration storage.

For engineers reviewing the X28HC64SZ-12 datasheet, X28HC64SZ-12 pinout, X28HC64SZ-12 application, or X28HC64SZ-12 equivalent, key selection considerations include its 5V-only operation, 120 ns read timing, 28-pin SOIC RoHS-compliant packaging, page write capability (64-byte burst), and dual hardware/software write protection mechanisms.

Technical Context

The X28HC64SZ-12 implements a floating-gate CMOS EEPROM array with two-line control architecture (CE/OE for reads, CE/WE for writes), enabling bus contention-free operation in multi-device memory systems. Its internal timing logic latches address on the later falling edge of CE or WE and data on the earlier rising edge, supporting self-timed write cycles without external high-voltage circuitry.

It integrates dual end-of-write detection: I/O7 toggles complemented data during programming (DATA Polling), while I/O6 toggles state on successive reads (Toggle Bit). Both methods eliminate need for external status interrupts and support host-side polling during page writes-where up to 64 consecutive bytes must share identical A6–A12 page address and be loaded within 100 µs intervals.

Key Specifications

Pinout & Package

Package: 28-lead SOIC (300 mil, RoHS-compliant, M28.3 drawing), surface-mount, moisture sensitivity level per Intersil product information page.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT28C64B-15PU and M95640-DWMN6TP, the X28HC64SZ-12 delivers faster parallel access (120 ns), native SOIC RoHS packaging, and integrated page write-making it optimal for 5V microcontroller-based systems needing deterministic, high-throughput nonvolatile storage without SPI driver development.

Availability

X28HC64SZ-12 is available at Aetrix Electronics and suitable for industrial PLC configuration storage, medical device calibration data retention, and networking equipment bootloader parameter management requiring stable component supply across extended production lifecycles.

Supply support for X28HC64SZ-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 provider of precision analog and power management ICs, acquired by Renesas Electronics in 2017; its legacy EEPROM portfolio emphasizes reliability, 5V compatibility, and JEDEC-standard interoperability.

The X28HC64 family was designed for embedded systems requiring robust, pin-compatible nonvolatile memory with simplified 5V-only operation and high endurance-targeting industrial control, medical instrumentation, and communications infrastructure.

FAQ

What is the maximum operating temperature range for the X28HC64SZ-12?

The X28HC64SZ-12 is rated for 0°C to +70°C commercial temperature operation. It is not qualified for industrial (-40°C to +85°C) range-those requirements are met by variants like X28HC64SIZ-12. Thermal resistance θJA is 46°C/W for its 28-lead SOIC package, requiring appropriate PCB copper area for thermal management at full active current (40 mA max).

Does the X28HC64SZ-12 require external high-voltage programming circuitry?

No, the X28HC64SZ-12 operates from a single 5V supply and contains fully integrated charge pumps for internal programming voltage generation. All write operations-including byte, page, and software protection enable/disable sequences-are executed with standard TTL/CMOS logic levels on CE, WE, and OE, eliminating need for external VP-P generators or complex timing controllers.

How does the page write function work on the X28HC64SZ-12?

The X28HC64SZ-12 supports 64-byte page writes: after initiating the first byte write, up to 63 additional bytes may be loaded within 100 µs intervals while maintaining identical A6–A12 page address bits. The internal programming cycle starts automatically if the 100 µs window expires. This enables full 64kbit write in ~0.25 seconds-significantly faster than discrete byte writes.

Can the X28HC64SZ-12 be used as a direct replacement for standard SRAMs?

Yes-the X28HC64SZ-12 uses JEDEC-approved byte-wide pinout identical to 8k×8 SRAMs (e.g., 6264), allowing mechanical and layout compatibility. However, write timing differs: SRAM writes complete instantly, while X28HC64SZ-12 requires polling (DATA or Toggle Bit) or fixed 2 ms delays. Read timing (120 ns) matches common SRAMs, enabling seamless read replacement.

What write protection mechanisms does the X28HC64SZ-12 provide?

The X28HC64SZ-12 provides three layers: (1) hardware default VCC sense (<3V inhibits writes), (2) hardware logic inhibition (OE LOW, WE HIGH, or CE HIGH blocks writes), and (3) nonvolatile software protection enabled via a 3-byte command sequence. Once set, software protection persists until explicitly reset using a 6-step deactivation algorithm-ensuring data integrity across power cycles.