Alternatives to STMicroelectronics M27C256B-10F1
STMicroelectronics M27C256B-10F1 and its qualified second sources, compared on form/fit/function, stock, lifecycle and price — the same checks Parter runs inside a BOM.
 M27C256B-10F1STMicroelectronics |  AT27C256R-70PUMicrochip Technology |  AT28C256-15PUMicrochip Technology | +1more | |
|---|---|---|---|---|
| FFF Compatibility | Utilizes a plastic 28-pin PDIP package instead of the windowed ceramic FDIP package, but retains exact pin assignment compatibility.Standard 28-pin DIP form factor with matching lead pitch, but uses a solid plastic body without a quartz erasure window.Meets all critical voltage (4.5V to 5.5V), organization (32K x 8), and speed requirements. | Pinout is incompatible due to different assignments on Pin 1 (A14 vs VPP) and Pin 27 (~WE vs A14).Employs a standard 28-pin plastic DIP package with identical footprint spacing.Slower read access time of 150 ns compared to the original 100 ns, though it functions as a 32K x 8 parallel non-volatile memory. | ||
 AI Summary | M27C256B-10F1 by STMicroelectronics: EPROM - UV Memory IC 256Kbit Parallel 100 ns 28-CDIP Frit Seal with Window. | The AT27C256R-70PU is an active, modern OTP (One-Time Programmable) EPROM variant that matches the pinout and electrical parameters of the original part. It features a faster 70 ns access time but cannot be erased under UV light due to its windowless plastic package.
| The AT28C256-15PU is an active parallel EEPROM that serves as an electrical-upgrade alternative. It requires wiring or socket modifications because of pinout differences (specifically Pins 1 and 27) but allows direct electrical write/erase cycles.
| |
| Lifecycle Status | Obsolete | Active | Active | |
| Market Availability | Non-stock | In stock | In stock | |
| REACH | REACH | REACH | REACH | |
| RoHS | RoHS | RoHS | RoHS | |
| Description | EPROM - UV Memory IC 256Kbit Parallel 100 ns 28-CDIP Frit Seal with Window | EPROM - OTP Memory IC 256Kbit Parallel 70 ns 28-PDIP | EEPROM Memory IC 256Kbit Parallel 150 ns 28-PDIP | |
| Manufacturer | STMicroelectronics | Microchip Technology | Microchip Technology | |
| Type | Memory | Memory | Memory | |
| Datasheet | Open | Open | Open | |
| Lead Time | 17 weeks | 6 weeks | 7 weeks | |
| Country of Origin | FR | - | - | |
| Export Control Class Number | OBSOLETE | EAR99 | EAR99 | |
| HTSUS Code | 8542.32.0061 | - | - | |
| Moisture Sensitivity Level | 1 (Unlimited) | - | - | |
| Technology | EPROM - UV | - | - | |
| Access Time | 100 ns | - | - | |
| Memory Size | 256Kbit | - | - | |
| Memory Type | Non-Volatile | - | - | |
| Memory Format | EPROM | - | - | |
| Mounting Type | Through Hole | - | - | |
| Package / Case | 28-CDIP (0.600", 15.24mm) Window | - | - | |
| Memory Interface | Parallel | - | - |
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Related parts
| Part | Market availability | Lifecycle | Alternatives available |
|---|---|---|---|
 M27C256B-15F1STMicroelectronics | Discontinued | Obsolete | 4Alternatives availableSee Alternatives |
 M27C4002-10F1STMicroelectronics | Non-stock | Obsolete | 3Alternatives availableSee Alternatives |
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Frequently asked questions
Yes. The STMicroelectronics M27C256B-10F1 is marked obsolete, so the manufacturer has discontinued it and any remaining supply is limited to distributor stock. The qualified second sources on this page are active parts you can design in today.
The closest qualified second sources for the STMicroelectronics M27C256B-10F1 are the AT27C256R-70PU (Microchip Technology) and the AT28C256-15PU (Microchip Technology), out of 3 matched alternatives in total. Each is compared against the original on fit, form and function in the table above.
Not always. The alternatives to the M27C256B-10F1 are matched on function but can differ in package, pinout or a key parameter, so review the fit/form/function notes in the table and the datasheet before designing one in.
The M27C256B-10F1 (STMicroelectronics) is a part in the Memory category. This page lists qualified, cross-referenced replacements for it with a side-by-side comparison.
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