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STMicroelectronics M27C256B-15F1
- Part No.:
- M27C256B-15F1
- Manufacturer:
- STMicroelectronics
- Category:
- Memory
- Package:
- 28-CDIP (0.600", 15.24mm) Window
- Datasheet:
-
M27C256B-15F1.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 28CDIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,520
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Product details
Overview
M27C256B-15F1 from STMicroelectronics is a 256 Kbit (32K × 8) UV-erasable EPROM in FDIP28W ceramic window package, operating at 5V ±10%, with 150 ns access time, 30 mA active current, and 100 µA standby current. It serves as non-volatile program storage in legacy microprocessor systems requiring field-erasable firmware, such as industrial PLCs, telecom line cards, and embedded instrumentation.
For engineers reviewing the M27C256B-15F1 datasheet, M27C256B-15F1 pinout, M27C256B-15F1 application, or M27C256B-15F1 equivalent, key selection criteria include UV erasure capability, TTL-compatible control timing (tAVQV = 150 ns), dual-line enable architecture (E/G), VPP = 12.75 V programming voltage, and FDIP28W package compatibility with UV exposure fixtures.
Technical Context
The M27C256B-15F1 implements a two-control-line architecture with Chip Enable (E) for device selection and Output Enable (G) for output gating-enabling low-power array operation and eliminating bus contention. Its UV-erasable silicon-gate CMOS process supports full 32K-word parallel programming at 100 µs/word with PRESTO II margin verification.
Electronic signature mode uses A9 = 11.5–12.5 V to read manufacturer code 20h and device code 8Dh on Q7–Q0; programming requires VCC = 6.25 V ±0.25 V and VPP = 12.75 V ±0.25 V applied synchronously, with E pulsed low for 95–105 µs while G = VIH.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32,768 × 8), enabling full 8-bit microprocessor code/data storage without banking |
| Access Time | 150 ns (tAVQV), compatible with 6 MHz Z80/8085/68000 bus cycles |
| Supply Voltage | 5 V ±10% in read mode; 6.25 V ±0.25 V required during programming |
| Programming Voltage | VPP = 12.75 V ±0.25 V, necessitating dedicated high-voltage circuitry in programmers |
| Standby Current | 100 µA (CMOS E high), reducing system power in idle states |
| Operating Temp | –40 °C to 125 °C, supporting industrial and automotive under-hood applications |
| Erasure Method | UV light (2537 Å, ≥15 W·s/cm²), requiring 15–20 min exposure at ≤2.5 cm from lamp |
Pinout & Package
FDIP28W (28-pin ceramic frit-seal DIP with UV-transparent window), 0.6-inch width, 36.5–37.3 mm length, 15.2 mm width, 5.7 mm height, designed for UV erasure and socketed prototyping.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus interface; A9 used for Electronic Signature voltage injection (11.5–12.5 V) |
| Q0–Q7 | Data Outputs | 8-bit bidirectional data bus; carry programmed data during read, accept data during programming |
| E | Chip Enable | Active-low primary device select; controls power state (30 mA active / 100 µA standby) |
| G | Output Enable | Active-low output gate; enables Q0–Q7 only when E is low, preventing bus contention |
| VPP | Programming Supply | 12.75 V input for programming; must be applied simultaneously with or after VCC |
| VCC | Supply Voltage | 5 V ±10% for read; 6.25 V ±0.25 V for programming-requires separate regulation |
| VSS | Ground | Reference for all I/O and supply pins; decoupling requires 0.1 µF ceramic + 4.7 µF bulk per 8 devices |
| NC | No Connect | Internally unconnected pins (e.g., PLCC32 pin 17); must remain floating or grounded per layout |
| DU | Don't Use | Pins reserved for test or future use (e.g., FDIP28W pin 17); no external connection permitted |
Key Features
| Feature | Design Value |
|---|---|
| Dual-line output control (E/G) | Enables zero-bus-contention memory arrays and reduces active power by >99% in standby |
| PRESTO II programming algorithm | Guarantees cell margin via automatic verify-in-margin-mode; eliminates overprogramming risk |
| Electronic Signature (20h/8Dh) | Allows automated programmer identification of STMicroelectronics origin and part type |
| UV erasability (2537 Å) | Supports >100 erase/write cycles with proper lamp calibration and window protection |
| TTL-compatible timing | Meets standard 8080/Z80 bus setup/hold requirements without glue logic |
Applications
| Industrial PLC Firmware Storage | Legacy Telecom Line Card Boot Code |
|---|---|
Use Scenario: Storing ladder logic firmware in DIN-rail mounted programmable logic controllers with field-upgrade requirement. IC Role / Device Role / Timing Role: Non-volatile boot ROM accessed at power-on reset; E tied to address decoder, G driven by CPU RD# signal. Use Value: UV erasure allows reprogramming after logic updates without PCB replacement; 150 ns access meets 6 MHz bus timing. | Use Scenario: Holding initialization code and protocol stacks in T1/E1 line interface units deployed in central office environments. IC Role / Device Role / Timing Role: Primary program memory mapped at 0x0000–0x7FFF; E decoded from chip-select logic, G shared across multiple EPROMs. Use Value: –40 °C to 125 °C rating ensures reliability in temperature-controlled CO cabinets; 100 µA standby minimizes thermal load. |
| Embedded Instrumentation Calibration Data | Avionics Test Equipment Configuration |
Use Scenario: Storing sensor calibration coefficients and linearization tables in portable multimeters and oscilloscopes. IC Role / Device Role / Timing Role: Read-only data storage accessed during self-test; A0–A14 driven by microcontroller, Q0–Q7 latched into RAM. Use Value: Electronic Signature (20h/8Dh) enables automated calibration file matching in production test software. | Use Scenario: Holding FPGA configuration bitstreams and diagnostic routines in airborne maintenance test sets. IC Role / Device Role / Timing Role: Boot ROM for ColdFire-based controller; VPP isolated via relay during normal operation to prevent accidental programming. Use Value: FDIP28W ceramic package withstands vibration and thermal cycling; UV window permits depot-level firmware revision. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar UV-erasable EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C256B-15J | Same 256 Kbit × 8 organization, 150 ns access, but uses JEDEC-standard PDIP28 (no UV window); requires OTP or UV-erasable variants separately | Not field-erasable; suitable only where one-time programming suffices or UV erasure is unavailable | Select only if UV window is unnecessary and cost reduction is prioritized over reprogrammability |
| MX27C256-15PC | Pin-compatible 256 Kbit EPROM with identical FDIP28W package and 150 ns speed, but manufactured by Macronix; electronic signature codes differ (2Ch/8Dh) | Requires updated programmer firmware to recognize alternate manufacturer ID; same UV erasure profile | Valid drop-in alternative if STMicroelectronics supply is constrained, provided signature-handling logic is updated |
Compared with M27C256B-15F1, AM27C256B-15J eliminates UV erasure capability but lowers cost for fixed-code deployments, while MX27C256-15PC offers identical functionality with vendor-diversified sourcing-both require verification of VPP timing compliance and signature-read logic adaptation.
Availability
M27C256B-15F1 is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy telecom line card boot code, and embedded instrumentation calibration data requiring stable component supply across extended product lifecycles.
Supply support for M27C256B-15F1 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in microcontrollers, power management, and non-volatile memory solutions for industrial, automotive, and consumer markets.
The M27C series targets legacy system maintenance and long-lifecycle embedded applications where UV-erasable programmability, wide temperature operation, and socket-based field upgrades remain essential design requirements.
FAQ
What UV wavelength and exposure dose are required to fully erase M27C256B-15F1?
The M27C256B-15F1 requires short-wave ultraviolet light at 2537 Å with a minimum integrated dose of 15 W·s/cm². Using a 12,000 µW/cm² lamp, erasure takes 15–20 minutes at ≤2.5 cm distance. Fluorescent lighting causes slow degradation (erasure in ~3 years), so opaque labels are recommended for long-term storage.
Can M27C256B-15F1 be operated with VCC = 5 V during programming?
No. Programming requires VCC = 6.25 V ±0.25 V and VPP = 12.75 V ±0.25 V applied simultaneously or with VCC before VPP. Using 5 V for VCC during programming results in incomplete or unreliable bit programming and violates the absolute maximum ratings.
How does the dual E/G control improve system-level memory array design?
The E (Chip Enable) and G (Output Enable) lines allow independent power and output control: E selects the device (activating 30 mA current), while G gates outputs (Q0–Q7) without affecting power state. This prevents bus contention in multi-chip arrays and reduces total standby current to 100 µA per device-even when G is active.
Is the FDIP28W package RoHS-compliant?
The M27C256B-15F1 FDIP28W package contains leaded solder in the ceramic-to-metal seal and is not RoHS-compliant. It complies with legacy industrial standards (e.g., MIL-STD-883) but requires exemption documentation for modern EU/US environmental compliance programs.
M27C256B-15F1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 28-CDIP (0.600", 15.24mm) Window
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EPROM
- Technology:
- EPROM - UV
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 150 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-CDIP Frit Seal with Window
M27C256B-15F1 FAQ
1.How can I place an order for M27C256B-15F1 through Aetrix?
Please submit a Request for Quotation (RFQ) for M27C256B-15F1 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 M27C256B-15F1 reliable?
The price and inventory of M27C256B-15F1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for M27C256B-15F1 is usually 5 days.
3.What payment methods are accepted for M27C256B-15F1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for M27C256B-15F1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for M27C256B-15F1?
M27C256B-15F1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your M27C256B-15F1 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 M27C256B-15F1?
For technical support, including M27C256B-15F1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your M27C256B-15F1 requirements.
6.How does Aetrix verify that M27C256B-15F1 is sourced from the original manufacturer or authorized distributors?
All M27C256B-15F1 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 M27C256B-15F1 meets industry standards.
7.What is the process for return or replacement of M27C256B-15F1?
All M27C256B-15F1 units undergo pre-shipment inspection (PSI). If there is an issue with M27C256B-15F1, 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 M27C256B-15F1 part is unused and in its original packaging.
Return procedure for M27C256B-15F1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
M27C256B-15F1 Tags
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M24C02-WMN6TP
STMicroelectronics
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AT24C02C-XHM-T
Microchip Technology
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AT21CS01-STUM10-T
Microchip Technology
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24LC01BT-I/OT
Microchip Technology
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M24C02-FMC6TG
STMicroelectronics
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AT24CS02-SSHM-T
Microchip Technology
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93LC46BT-I/OT
Microchip Technology
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AT24C04C-SSHM-T
Microchip Technology
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24LC01BT-I/SN
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24AA02UIDT-I/OT
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AT24C08C-STUM-T
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