Renesas X28HC64PZ-90

Overview

X28HC64PZ-90 from Intersil is a 64 kbit (8k × 8), 5V-only, byte-alterable EEPROM in 28-pin PDIP package, featuring 90 ns access time, 2 ms typical byte/page write cycle, 100,000 write endurance, and 100-year data retention - used for nonvolatile configuration storage in industrial control panels and legacy embedded systems requiring simple, single-supply memory updates.

For engineers reviewing the X28HC64PZ-90 datasheet, X28HC64PZ-90 pinout, X28HC64PZ-90 application, or X28HC64PZ-90 equivalent, this page delivers verified JEDEC-compliant pin mapping, real-world endurance and timing specs, software/hardware data protection implementation details, and validated drop-in alternatives for legacy system maintenance and BOM continuity planning.

Technical Context

The X28HC64PZ-90 implements a self-timed, single 5V supply EEPROM architecture with dual-line control (CE/OE/WE) to eliminate bus contention. It supports both byte and 64-byte page writes without prior erase, using internal charge-pump programming and automatic completion detection via DATA Polling (I/O7) or Toggle Bit (I/O6).

Its JEDEC-approved 28-pin PDIP pinout matches industry-standard SRAM layouts, enabling direct replacement in existing 8-bit microcontroller address/data bus interfaces. Hardware write protection is enforced by VCC sense (inhibit below ~3V) and signal-level gating (OE low, WE high, or CE high), while optional nonvolatile software protection requires a 3-byte unlock sequence before each write window.

Key Specifications

Pinout & Package

Package: 28-pin Plastic Dual In-line Package (PDIP), RoHS-compliant, through-hole mount, E28.6 drawing, 0.600" width.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT28C64B-15PU and MX28LV640CT-90P, the X28HC64PZ-90 delivers superior long-term data integrity (100-year retention), lower active power (40 mA vs. 10 mA but with tighter timing margin), and proven JEDEC pinout compatibility for drop-in replacement in aging industrial hardware - making it the optimal choice for lifecycle extension of legacy systems.

Availability

X28HC64PZ-90 is available at Aetrix Electronics and suitable for industrial control panels, medical device calibration storage, and automotive body control modules requiring stable component supply and long-term BOM continuity.

Supply support for X28HC64PZ-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 was a U.S.-based semiconductor company specializing in high-reliability analog and nonvolatile memory solutions, later acquired by Renesas Electronics in 2017.

The X28HC64 product line was designed for industrial and embedded applications demanding robust, single-supply EEPROM functionality with JEDEC-standard compatibility and extended data retention - targeting legacy system maintenance and long-lifecycle deployments.

FAQ

What is the operating temperature range for the X28HC64PZ-90?

The X28HC64PZ-90 is rated for commercial temperature operation from 0°C to +70°C, as confirmed in the Ordering Information table on page 2 of FN8109 Rev 4.00. Its 28-pin PDIP package (E28.6) is specified for this range, and thermal resistance θ_JA is 53°C/W under standard test conditions. This makes the X28HC64PZ-90 suitable for indoor industrial and office environments but not extended-temperature applications - for which the -40°C to +85°C X28HC64PIZ-90 variant is recommended.

Does the X28HC64PZ-90 require external high-voltage circuitry for programming?

No, the X28HC64PZ-90 does not require external high-voltage circuitry. It is a 5V-only device that uses an internal charge-pump to generate programming voltage, as stated on page 1 of FN8109 Rev 4.00. All write operations - whether byte or 64-byte page - are initiated with standard TTL/CMOS logic levels on CE, WE, and OE, eliminating the need for VP-P generators, external regulators, or complex timing controllers. This simplifies design and reduces bill-of-materials cost in 8-bit embedded systems.

How does software data protection work on the X28HC64PZ-90?

Software data protection on the X28HC64PZ-90 is enabled via a nonvolatile 3-byte unlock sequence written to specific addresses (0x5555, 0x2AAA, 0x5555) before any write operation, as detailed in Figures 7–8 of FN8109 Rev 4.00. Once set, the device remains write-protected until the six-step reset sequence is issued. The feature is shipped disabled and becomes persistent across power cycles - providing robust protection against accidental writes during power-up/down without requiring external hardware, unlike basic VCC-sense or signal-gating methods.

Can the X28HC64PZ-90 be used in place of a standard SRAM like the 6264?

Yes, the X28HC64PZ-90 can serve as a functional replacement for the 6264 SRAM in many systems due to its JEDEC-approved byte-wide pinout and identical 28-pin PDIP footprint, as noted on page 1 of FN8109 Rev 4.00. However, it is not a direct functional substitute: unlike SRAM, it requires write-enable sequencing and has slower write timing (2 ms vs. nanosecond writes). It is best suited for configuration storage - not volatile runtime memory - and must be integrated with appropriate polling or delay logic in the host firmware.

What are the key differences between the X28HC64PZ-90 and the X28HC64JZ-90?

The X28HC64PZ-90 uses a 28-pin PDIP package (E28.6) rated for 0°C to +70°C operation, while the X28HC64JZ-90 uses a 32-pin PLCC package (N32.45x55) and is also commercial-temp rated. Both share identical electrical specifications (90 ns access, 2 ms write, 100,000 cycles), but the PDIP version supports wave-solder processing only (per Note 5), whereas the PLCC supports surface-mount reflow. The pin count and layout differ significantly - they are not pin-compatible, and PCB layout changes are required for substitution.