ATMEL AT28HC256F-90FM/883 (5962-88634 04 ZA)
- 256Kbit (32K × 8) high-speed CMOS parallel EEPROM with 90ns access time
- Fast-write F option: 3ms write cycle time — 3× faster than the standard AT28HC256
- Internal error correction circuit for extended reliability in military environments
- Hermetic 28-lead ceramic flatpack for space-constrained defense PCB assemblies
- MIL-STD-883 Class B screened, DESC SMD 5962-88634 04 ZA, −55°C to +125°C
Atmel (now Microchip Technology) designed the AT28HC256F as the fast-write variant within the HC256 military EEPROM family — combining the 90ns read performance of the AT28HC256 architecture with a 3ms internal write cycle time that is three times faster than the standard 10ms operation. The AT28HC256F-90FM/883 is available from stock at Sparkle Electronics, a specialized distributor of military-grade and high-reliability electronic components serving defense prime contractors, avionics system integrators, and government procurement offices worldwide. For defense programs requiring rapid in-system firmware updates, high-throughput mission data writes, or tight write-cycle timing budgets in embedded military processors, the F option eliminates the write cycle as a system bottleneck without any change to the bus interface or package footprint.
The FM ceramic flatpack package positions the AT28HC256F-90FM/883 for high-density, space-constrained defense PCB assemblies where the profile of a Cerdip or LCC package cannot be accommodated. The military version of the HC architecture includes an on-chip error correction circuit that extends effective data retention and endurance under thermal cycling and radiation stress — a reliability feature not present in the standard AT28C256 family. Procurable under DESC SMD number 5962-88634 04 ZA, the part carries full QPL traceability for DLA defense procurement. Contact Sparkle Electronics to confirm stock and request a same-day quote.
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DESC SMD Number: 5962-88634 04 ZA
The AT28HC256F-90FM/883 is procurable under DESC Standard Military Drawing number 5962-88634 04 ZA, issued by the Defense Logistics Agency (DLA) Defense Electronics Supply Center. This SMD number places the part within the DLA Qualified Products List (QPL) system, providing the regulatory traceability chain required by defense contracts subject to MIL-SPEC sourcing obligations.
The SMD number differentiates the F fast-write variant (04 ZA) from the standard AT28HC256-90FM/883 (03 ZA) within the same DESC family — procurement teams must specify the correct suffix when ordering under QPL requirements to ensure the fast-write variant is supplied. For programs sourcing 5962-88634 04 ZA stock or verifying QPL qualification for fast-write EEPROM procurement, Sparkle Electronics supplies the AT28HC256F-90FM/883 with certificate of conformance, MIL-STD-883 screening test records, and country of origin documentation. Contact our team to discuss documentation requirements before placing your order.
AT28HC256F-90FM/883: When 3ms Write Time Changes the System Design Equation
In military embedded systems with deterministic timing requirements, a 10ms EEPROM write cycle can impose real constraints on interrupt latency, task scheduling, and processor utilization during bulk update operations. The AT28HC256F-90FM/883 compresses that window to 3ms — without any change to the parallel bus interface, pin assignment, or operating voltage. For procurement engineers searching AT28HC256F-90FM/883 in stock, 5962-88634 04 ZA aerospace distributor, or fast-write MIL-STD-883 EEPROM flatpack, Sparkle Electronics maintains ready inventory with same-day response. Submit an inquiry for pricing and stock confirmation within 24 hours.
The F Option: What a 3ms Write Cycle Enables That 10ms Cannot
A 10ms write cycle is acceptable for infrequent firmware updates or fixed-configuration storage. It becomes a design constraint in applications where the processor must suspend bus activity for the write duration, or where write operations occur within time-critical control loops. The AT28HC256F-90FM/883’s 3ms write cycle reduces bus unavailability by 70% per write operation — directly improving system responsiveness in adaptive radar parameter updates, missile guidance reconfiguration, and onboard calibration storage where write timing is on the critical path.
AT28HC256F-90FM/883 vs. Standard and High-Endurance Variants
| Parameter | AT28HC256F-90FM/883 | AT28HC256-90FM/883B | AT28HC256E-90FM/883 |
|---|---|---|---|
| Manufacturer | Atmel / Microchip | Atmel / Microchip | Atmel / Microchip |
| Availability | In Stock at Sparkle | In Stock at Sparkle | — |
| Access Time | 90ns | 90ns | 90ns |
| Write Cycle Time | 3ms (fast) | 10ms (standard) | 10ms (standard) |
| Write Endurance | 10,000 cycles | 10,000 cycles | 100,000 cycles |
| Package | 28-lead Ceramic Flatpack | 28-lead Ceramic Flatpack | 28-lead Ceramic Flatpack |
| Active Current | 80mA max | 80mA max | 80mA max |
| Standby Current | 300µA max | 5mA max | 5mA max |
| Internal ECC | Yes (military) | Yes (military) | Yes (military) |
| Temperature Range | −55°C to +125°C | −55°C to +125°C | −55°C to +125°C |
| Screening | MIL-STD-883 Class B | MIL-STD-883 Class B | MIL-STD-883 Class B |
| SMD Number | 5962-88634 04 ZA | 5962-88634 03 ZA | N/A |
One additional advantage of the F variant: its standby current (300µA) is significantly lower than the standard AT28HC256 (5mA), making it the better choice for power-sensitive military platforms where the EEPROM spends extended periods in standby between write operations — a common profile in battery-backed avionics and missile electronics.
MIL-STD-883 Class B Screening and QPL Traceability
MIL-STD-883 Class B screening for the AT28HC256F-90FM/883 covers 100% burn-in at elevated temperature, electrical characterization at −55°C and +125°C extremes, and hermetic seal verification of the ceramic flatpack. For defense procurement programs requiring DLA QPL-qualified fast-write EEPROM or MIL-STD-883 screening documentation for avionics qualification, Sparkle Electronics provides full conformance documentation on request. The ceramic flatpack construction satisfies the hermeticity requirements of MIL-STD-883 — a requirement that plastic-packaged commercial EEPROM cannot meet regardless of speed grade.
For related Atmel military EEPROM options available from Sparkle Electronics: the ATMEL AT28HC256-90FM/883B offers the same flatpack package and access speed with standard 10ms write timing for applications where write speed is not a constraint. The ATMEL AT28HC256-90LM/883 provides the same 90ns performance in a hermetic ceramic LCC for SMT-compatible high-density board designs. For programs requiring higher write endurance over write speed, the ATMEL AT28C256E-15FM/883 delivers 100,000-cycle endurance under equivalent MIL-STD-883 Class B screening in a ceramic flatpack.
Frequently Asked Questions
What does AT28HC256F-90FM/883 decode to?
AT28 = Atmel EEPROM family; HC = high-speed CMOS with internal error correction (military version); 256 = 256Kbit (262,144 bits); F = fast-write option (3ms write cycle); −90 = 90ns access time; F = 28-lead ceramic flatpack package; M = military temperature range (−55°C to +125°C); /883 = MIL-STD-883 Class B screening.
Where can I buy AT28HC256F-90FM/883 in stock?
Sparkle Electronics maintains ready stock of the AT28HC256F-90FM/883 for defense and aerospace procurement. Contact our team for current pricing, available quantity, and confirmed lead time. We serve defense contractors, government procurement offices, and aerospace integrators globally with same-day response on qualified inquiries.
What is the DESC SMD number for AT28HC256F-90FM/883?
5962-88634 04 ZA — the Defense Electronics Supply Center Standard Military Drawing number for the AT28HC256F-90FM/883. Note that the standard AT28HC256-90FM/883 carries SMD 5962-88634 03 ZA — the 04 suffix specifically identifies the F fast-write variant. Specifying the correct suffix is required for QPL-traceable DLA procurement.
What is the practical difference between a 3ms and 10ms write cycle in a military system?
In a system performing 100 page writes during a firmware update, 10ms write cycles consume 1 second of bus time versus 300ms for the F variant — a 70% reduction. In time-critical embedded control loops where EEPROM writes occur within deterministic scheduling windows, the 3ms write cycle may be the deciding factor that allows the EEPROM to be used at all without introducing system timing violations.
Does the F fast-write option trade endurance for write speed?
No. The AT28HC256F-90FM/883 retains the same 10,000 minimum write cycle endurance as the standard AT28HC256. The F option accelerates the internal write timing from 10ms to 3ms without reducing cycle life. For applications requiring both fast write and extended endurance, evaluate the AT28HC256E variant, which provides 100,000 write cycles at standard 10ms write timing.
Is AT28HC256F-90FM/883 a drop-in replacement for AT28HC256-90FM/883?
Yes, with one important note. The pin assignment, bus interface, operating voltage, and ceramic flatpack package are identical. The write cycle timing changes from 10ms to 3ms, and standby current drops from 5mA to 300µA. Any system firmware that polls DATA or toggle-bit write completion will automatically accommodate the shorter write cycle. Systems with hard-coded 10ms delays may complete the wait period unnecessarily but will function correctly. Contact us for substitution verification support on your specific application.
Procuring AT28HC256F-90FM/883 for a time-critical defense or aerospace program? Sparkle Electronics stocks Atmel fast-write military EEPROM with full MIL-STD-883 and QPL documentation support for DLA procurement workflows. Submit an inquiry — same-day response on pricing, stock confirmation, and lead time.
