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ATMEL AT28HC256 Data Handbook

Summary

This high-performance EEPROM offers reliable nonvolatile storage for embedded systems requiring robust data retention. Featuring ultra-fast access times (70 ns) and advanced low-power operation, it supports hardware and software data protection against inadvertent writes. This manual provides comprehensive technical specifications, detailed operational procedures, and pin configurations necessary for system designers implementing durable, high-speed memory solutions in commercial or industrial applications.

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Page 1 Text Content

查询AT28HC256供应商

Features I/O I/O

Fast Read Access Time - 70 ns Automatic Page Write Operation

Internal Address and Data Latches for 64 Bytes I/O I/O

Internal Control Timer I/O Fast Write Cycle Times Page Write Cycle Time: 3 ms or 10 ms Maximum 1 to 64-Byte Page Write Operation Low Power Dissipation 80 m A Active Current 3 m A Standby Current 256 (32K x 8) Hardware and Software Data Protection DATA Polling for End of Write Detection

High Speed

High Reliability CMOS Technology Endurance: 104 or 105 Cycles

Data Retention: 10 Years Parallel

Single 5V ± 10% Supply CMOS and TTL Compatible Inputs and Outputs EEPROMs JEDEC Approved Byte-Wide Pinout Full Military, Commercial, and Industrial Temperature Ranges

AT28HC256

Description The AT28HC256 is a high-performance Electrically Erasable and Programmable Read Only Memory. Its 256K of memory is organized as 32,768 words by 8 bits. Man- ufactured with Atmel’s advanced nonvolatile CMOS technology, the AT28HC256

(continued)

Pin Configurations TSOP

Top View

Pin Name Function A0 - A14 Addresses OE A10

A11 CE

CE Chip Enable A9 I/O7

OE Output Enable A13 I/O5

WE I/O4

WE Write Enable VCC I/O3

A14 GND

I/O0 - I/O7 Data Inputs/Outputs A12 I/O2

NC No Connect A6 I/O0

DC Don’t Connect

LCC, PLCC CERDIP, PDIP, FLATPACK PGA Top View Top View Top View

A14 VCC A12 WE A6 A8 A7 A13 A5 A9 A6 A8 A4 A11 A5 A9 A3 NC A4 A11 A2 OE A3 OE A1 A10 A2 A10 A0 CE A1 CE NC I/O7 A0 I/O7 I/O0 I/O6 I/O0 I/O6 I/O1 I/O5 I/O2 I/O4 GND I/O3

Rev. 0007G–10/98

Note: PLCC package pins 1 and 17 are DON’T CONNECT.

Page Summary Contents For ATMEL AT28HC256 Data Handbook

Page 1 查询AT28HC256供应商 Features I/O I/O Fast Read Access Time - 70 ns Automatic Page Write Operation Internal Address and Data Latches for 64 Bytes I/O I/O Internal Control Timer I/O Fast Write Cycle Times Pa...
Page 2 offers access times to 70 ns with power dissipation of just polling of I/O7. Once the end of a write cycle has been 440 m W. When the AT28HC256 is deselected, the standby detected a new access for a r...
Page 3 AT28HC256 Device Operation occur during transition of the host system power supply. Atmel has incorporated both hardware and software fea- READ: The AT28HC256 is accessed like a Static RAM. tures that...
Page 4 DC and AC Operating Range AT28HC256-70 AT28HC256-90 AT28HC256-12 Com. 0°C - 70°C 0°C - 70°C 0°C - 70°C Operating Ind. -40°C - 85°C -40°C - 85°C -40°C - 85°C Temperature (Case) Mil. -55°C - 125°C -55°C...
Page 5 AT28HC256 AC Read Characteristics AT28HC256-70 AT28C256-90 AT28HC256-12 Symbol Parameter Max Min Max Min Max Units Min t ACC Address to Output Delay ns (1) t CE CE to Output Delay ns (2) t OE OE to Ou...
Page 6 AC Write Characteristics Symbol Parameter Min Max Units t AS, t OES Address, OE Set-up Time ns t AH Address Hold Time ns t CS Chip Select Set-up Time ns t CH Chip Select Hold Time ns t WP Write Pulse ...
Page 7 AT28HC256 Page Mode Write Characteristics Symbol Parameter Min Typ Max Units AT28HC256 ms t WC Write Cycle Time AT28HC256F 3.0 ms t AS Address Set-up Time ns t AH Address Hold Time ns t DS Data Set-up...
Page 8 Software Data Protection Software Data Protection Enable Algorithm(1) Disable Algorithm(1) LOAD DATA AA LOAD DATA AA TO TO ADDRESS 5555 ADDRESS 5555 LOAD DATA 55 LOAD DATA 55 TO TO ADDRESS 2AAA ADDRES...
Page 9 AT28HC256 Data Polling Characteristics(1) Symbol Parameter Min Typ Max Units t DH Data Hold Time ns t OEH OE Hold Time ns t OE OE to Output Delay(2) ns t WR Write Recovery Time ns Notes: 1. These para...
Page 10 AT28HC25610
Page 11 AT28HC256 Ordering Information(1) t ACC ICC (m A) (ns) Standby Ordering Code Package Operation Range Active AT28HC256(E,F)-70JC 32J Commercial AT28HC256(E,F)-70PC 28P6 (0°C to 70°C) 0.3 AT28HC256(E,F)...
Page 12 Ordering Information(1) (Continued) t ACC ICC (m A) (ns) Standby Ordering Code Package Operation Range Active 0.3 5962-88634 03 UX 28U Military/883C 5962-88634 03 XX 28D6 Class B, Fully Compliant 5962...
Page 13 AT28HC256 Ordering Information Note Previous data sheets included the low power suffixes L, LE and LF on the At28HC256 for 120 ns and 90 ns speeds. The low power parameters are now standard; therefore...
Page 14 Packaging Information 28D6, 28-Lead, 0.600" Wide, Non-Windowed, 28F, 28-Lead, Non-Windowed, Ceramic Bottom- Ceramic Dual Inline Package (Cerdip) Brazed Flat Package (Flatpack) Dimensions in Inche...
Page 15 AT28HC256 Packaging Information 28P6, 28-Lead, 0.600" Wide, Plastic Dual Inline 28S, 28-Lead, 0.300" Wide, Plastic Gull Wing Small Package (PDIP) Outline (SOIC) Dimensions in Inches and (Mil...
Page 16 Atmel Headquarters Atmel Operations Corporate Headquarters Atmel Colorado Springs 2325 Orchard Parkway 1150 E. Cheyenne Mtn. Blvd. San Jose, CA 95131 Colorado Springs, CO 80906 TEL (408) 441-0311 TEL ...

Manual Details

Brand Atmel
Pages 16
File Size 449.26 KB
Published May 15, 2026
137 views

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Frequently Asked Questions

What is the fastest read access time available?

The device offers fast access times of 70 ns.

How can I protect against accidental memory writes?

It includes hardware features like voltage sense and write inhibit signals to prevent unintentional data corruption.

Does it automatically manage data during a write cycle?

Yes, the internal control timer automatically writes the latched 1 to 64 bytes of data after detecting the end of the write cycle.

What operating temperature range is supported?

The device supports full Military, Commercial, and Industrial Temperature Ranges.