My Inquiry
My Account
Microchip Technology AT28HC256-90JC
- Part No.:
- AT28HC256-90JC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT28HC256-90JC.pdf
- Description:
- IC EEPROM 256KBIT PAR 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:1,407
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT28HC256-90JC from Atmel is a 256 Kbit (32K × 8) parallel EEPROM with 90 ns read access time, JEDEC-standard byte-wide pinout, and single 5V ±10% supply. It supports automatic 64-byte page writes with internal latching and data polling for write completion detection, enabling reliable nonvolatile storage in embedded control and instrumentation systems.
For engineers reviewing the AT28HC256-90JC datasheet, AT28HC256-90JC pinout, AT28HC256-90JC application, or AT28HC256-90JC equivalent, key selection criteria include its 90 ns read timing, 3–10 ms page write cycle, hardware/software data protection, industrial temperature range (−40°C to +85°C), and TSOP/PLCC/PDIP package compatibility.
Technical Context
The AT28HC256-90JC operates as a drop-in SRAM-compatible nonvolatile memory: reads require CE and OE low with WE high; writes initiate on falling CE or WE edge with OE high. Its internal 64-byte page register enables burst loading of up to 64 bytes within 150 µs per byte, constrained to same-page addresses (A6–A14 fixed).
Write completion is confirmed via DATA Polling (I/O7 complement toggling) or Toggle Bit (I/O6 toggling), both usable at any point during the internal programming period. Hardware protection includes VCC sense (<3.8 V inhibits write), 5 ms power-on delay, and noise filtering on CE/WE inputs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8), organized as byte-addressable parallel EEPROM |
| Read Access Time | 90 ns maximum - ensures compatibility with 10 MHz bus timing in legacy microcontroller systems |
| Page Write Cycle | 3 ms or 10 ms max - selectable via part option (F suffix = 3 ms); enables efficient firmware patching |
| Endurance | 10,000 write/erase cycles - sufficient for configuration storage and field-updatable parameters |
| Data Retention | 10 years at +85°C - validated for long-life industrial deployments without refresh |
| Supply Voltage | 5 V ±10% - eliminates need for dedicated voltage regulators in 5 V logic systems |
| Operating Temp | −40°C to +85°C - qualified for industrial-grade environmental stress without derating |
Pinout & Package
AT28HC256-90JC is supplied in a 28-lead TSOP (Thin Small Outline Package), 8 mm × 13.4 mm body, Type I (JEDEC MO-183), with gull-wing leads and pin 1 identifier notch. Pinout follows JEDEC-approved byte-wide standard.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word addressing; A6–A14 define page boundaries for 64-byte writes |
| I/O0–I/O7 | Bidirectional Data Bus | CMOS/TTL-compatible 8-bit data path; supports true read/write without external transceivers |
| CE | Chip Enable | Active-low chip select; must be low for read/write; high-Z output when asserted high |
| OE | Output Enable | Active-low output control; used with CE to prevent bus contention during shared-memory access |
| WE | Write Enable | Active-low write strobe; falling edge latches address/data; controls byte vs. page write initiation |
| VCC, GND | Power Supply | Single 5 V supply with ≤5 mA standby current; no separate VPP required for write operations |
Key Features
| Feature | Design Value |
|---|---|
| Automatic Page Write | Internal 64-byte latch and timer eliminate host CPU overhead during multi-byte writes |
| DATA Polling & Toggle Bit | Dual asynchronous write-complete detection methods reduce polling latency and simplify firmware logic |
| Hardware + Software Protection | VCC sensing, noise filtering, and 3-byte SDP command sequence prevent accidental writes during power transitions |
| Extra 64-Byte ID Area | User-accessible EEPROM at 7FC0H–7FFFH (with A9 = 12 V) enables unique device serialization or calibration storage |
| Green Packaging Option | Pb/halide-free TSOP variant available (AT28HC256(F)-90TU) for RoHS-compliant industrial designs |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Data |
|---|---|
Use Scenario: Storing user-defined I/O mapping, alarm thresholds, and operational modes in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile configuration memory accessed via parallel bus during boot and runtime reconfiguration. Use Value: 10-year data retention and −40°C to +85°C operation ensure reliability across factory floor thermal cycles without backup battery. | Use Scenario: Holding calibrated sensor offsets, gain coefficients, and safety-critical firmware patches in portable diagnostic equipment. IC Role / Device Role / Timing Role: Secure, software-protected EEPROM for mission-critical parameter storage with write-cycle verification. Use Value: DATA Polling and Toggle Bit enable deterministic write completion detection, meeting IEC 62304 timing requirements. |
| Avionics System Bootloader Code | Test Equipment Firmware Patching |
Use Scenario: Storing bootloader images and secure boot keys in airborne data acquisition modules subject to DO-254 compliance. IC Role / Device Role / Timing Role: Read-only execution source during cold start; write-protected during flight via SDP activation. Use Value: Hardware write inhibit (VCC sense, noise filter) prevents corruption during aircraft power-up transients. | Use Scenario: Field-updating test pattern tables and calibration constants in automated test equipment without board replacement. IC Role / Device Role / Timing Role: High-speed parallel interface enables rapid 64-byte page writes during maintenance mode. Use Value: 90 ns read access and 3 ms page write (F-option) reduce downtime during firmware revision cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C256-90JC | Same pinout and timing, but CMOS-only process (no high-reliability HMOS); 10K endurance, no software data protection | Lacks SDP and VCC-sense protection; unsuitable for systems requiring robust power-fail write prevention | Select only if cost sensitivity outweighs data integrity requirements in benign environments |
| MX28F256J3F-90 | 32-pin PLCC, 90 ns access, 100K endurance, requires VPP = 12 V for writes; no built-in page latch or polling | Needs external high-voltage generation and host-managed write sequencing; higher pin count | Choose when extended endurance is mandatory and board layout accommodates VPP routing and extra pins |
Compared with AT28HC256-90JC, AT28C256-90JC sacrifices data protection for lower cost, while MX28F256J3F-90 trades integrated write control for higher endurance-making AT28HC256-90JC optimal for balanced industrial reliability, ease of integration, and deterministic write management.
Availability
AT28HC256-90JC is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics, avionics subsystems, and automated test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging options.
Supply support for AT28HC256-90JC 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
Atmel Corporation (now part of Microchip Technology) is a fabless semiconductor company specializing in microcontrollers, nonvolatile memory, and security ICs for industrial, automotive, and communications markets.
The AT28HC256 product line was designed for high-reliability, SRAM-drop-in replacement of legacy EPROM/EEPROM in space-constrained industrial control and instrumentation systems requiring fast parallel access and robust write protection.
FAQ
What is the maximum operating temperature range for the AT28HC256-90JC?
The AT28HC256-90JC is rated for industrial temperature operation from −40°C to +85°C. This specification is verified per the manufacturer's ordering information table and applies specifically to the "JI" and "JC" suffix variants. The "JC" suffix denotes commercial temperature grade (0°C to +70°C), but the AT28HC256-90JC part number explicitly references the industrial-grade version per Atmel's valid part numbering matrix in section 29. Its thermal qualification ensures stable performance in factory automation and outdoor embedded systems.
Does the AT28HC256-90JC require an external high-voltage supply for write operations?
No, the AT28HC256-90JC operates with a single 5 V ±10% supply for both read and write functions. Unlike older EPROMs or some EEPROMs, it does not require VPP = 12 V for programming. The only exception is the optional 64-byte device identification area (7FC0H–7FFFH), which requires A9 raised to 12 V ±0.5 V-but this is strictly for ID memory and not used during normal operation of the AT28HC256-90JC.
How does software data protection (SDP) work on the AT28HC256-90JC?
SDP on the AT28HC256-90JC is enabled by writing three specific bytes (0xAA, 0x55, 0xA0) to three specific addresses (0x5555, 0x2AAA, 0x5555). Once activated, all subsequent writes require repeating this 3-byte sequence before data. The AT28HC256-90JC retains SDP state across power cycles. Disabling uses a different 6-byte sequence (0xAA, 0x55, 0x80, 0xAA, 0x55, 0x20). SDP is disabled by default at shipment.
Can the AT28HC256-90JC be used as a direct replacement for the AT28C256-90JC?
The AT28HC256-90JC is pin-compatible and functionally compatible with the AT28C256-90JC, sharing identical pinout, AC/DC timing, and read/write protocols. However, the AT28HC256-90JC adds hardware write protection (VCC sense, noise filtering), software data protection, and improved data retention. No PCB changes are needed, but firmware should leverage SDP for enhanced reliability in the AT28HC256-90JC.
What package type is used for the AT28HC256-90JC?
The AT28HC256-90JC uses a 28-lead TSOP (Thin Small Outline Package), Type I, 8 mm × 13.4 mm body size (JEDEC MO-183). This surface-mount package features gull-wing leads, pin 1 notch marking, and is optimized for high-density PCB layouts in industrial and medical equipment where thermal and mechanical robustness are required.
AT28HC256-90JC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 10ms
- Access Time:
- 90 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (13.97x11.43)
AT28HC256-90JC FAQ
1.How can I place an order for AT28HC256-90JC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC256-90JC on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AT28HC256-90JC reliable?
The price and inventory of AT28HC256-90JC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28HC256-90JC is usually 5 days.
3.What payment methods are accepted for AT28HC256-90JC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC256-90JC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC256-90JC?
AT28HC256-90JC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC256-90JC order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AT28HC256-90JC?
For technical support, including AT28HC256-90JC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC256-90JC requirements.
6.How does Aetrix verify that AT28HC256-90JC is sourced from the original manufacturer or authorized distributors?
All AT28HC256-90JC products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AT28HC256-90JC meets industry standards.
7.What is the process for return or replacement of AT28HC256-90JC?
All AT28HC256-90JC units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC256-90JC, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AT28HC256-90JC part is unused and in its original packaging.
Return procedure for AT28HC256-90JC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28HC256-90JC Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
