X28HC256 256k, 32k X 8-Bit FN8108.3 EEPROM Data Sheet

Category: Electronics, Intersil Corporation, Memory ICS

Overview

The X28HC256 is a 256 kilobit (kbit) Electrically Erasable Programmable Read-Only Memory (EEPROM) chip, which operates on a single 5-volt (V) power supply. It features a 32k x 8 configuration, indicating the memory is organized as 32,768 word of 8 bits each. This chip, produced by Intersil using their proprietary textured poly floating gate technology, offers stable and reliable nonvolatile memory storage.

Main Features and Benefits

Key characteristics of the X28HC256 include an access time of 70 nanoseconds (ns) and both byte and page write capabilities, which simplify interaction for users. The high-speed page write operation allows for an effective write cycle of 24 microseconds (μs) per byte, permitting the rewriting of the entire memory typically in under 0.8 seconds.

The device does not require external high voltage for operation, making system integration easier. Self-timing capabilities eliminate the need for complex programming algorithms and there’s no need to erase before writing. Its low power consumption is highlighted by an active current of 60 milliamperes (mA) and a standby current of just 500 microamperes (μA).

Software Data Protection (SDP) is a notable feature that safeguards against unintended writes during power transitions. Another critical aspect is its endurance, specified at a minimum of 1,000,000 write cycles per byte with an inherent data retention capability of 100 years, signifying a highly durable memory storage solution.

The detection of the end of the write operation is made efficient by two features: DATA Polling and Toggle Bit Polling. The device is also compliant with Restriction of Hazardous Substances (RoHS) as Pb-free versions are available.

Device Composition and Handling

The datasheet presents a block diagram which gives a high-level overview of the device’s internal structure: a 256kbit EEPROM array, buffers, latches, decoders, address inputs, input/output (I/O) buffers, control logic, and timing circuits. The diagram illustrates the roles of the chip enable (CE), output enable (OE), and write enable (WE) signals, alongside the power supply (Vcc) and ground (Vss) connections.

It is also cautioned that the X28HC256 is sensitive to electrostatic discharge (ESD), and appropriate Integrated Circuit (IC) handling procedures should be followed to prevent damage.