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Home > Products > Integrated Circuits (ICs) > Memory > Memory

STMicroelectronics M27C4002-12C1

Name: M27C4002-12C1
Brand: STMicroelectronics
SKU: M27C4002-12C1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: M27C4002-12C1

Manufacturer:: STMicroelectronics

Category:: Memory

Package:: 44-LCC (J-Lead)

Datasheet:: M27C4002-12C1.pdf

Description:: IC EPROM 4MBIT PARALLEL 44PLCC

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Product details

Overview

M27C4002-12C1 from STMicroelectronics is a 4 Mbit (256K × 16) UV-erasable EPROM in a 44-lead PLCC package, operating at 5V ±10%, with 45ns access time, 70mA active current at 10MHz, and 100µA standby current. It supports two-line output control (E/G), electronic signature (20h/44h), and UV erasure via windowed ceramic package variants - used in legacy microprocessor boot ROMs and industrial firmware storage.

For engineers reviewing the M27C4002-12C1 datasheet, M27C4002-12C1 pinout, M27C4002-12C1 application, or M27C4002-12C1 equivalent, key selection factors include UV erasability vs. OTP variants, PLCC44 mechanical compatibility, 16-bit parallel data bus interface, PRESTO II programming algorithm timing, and ECOPACK® lead-free compliance for legacy system requalification.

Technical Context

The M27C4002-12C1 implements a TTL-compatible 16-bit parallel memory architecture with dual active-low control: Chip Enable (E) governs power state and device selection, while Output Enable (G) independently gates data onto Q0–Q15 outputs. Its read mode requires both E and G low for valid output, with tAVQV = 45ns and tGLQV = 25ns under high-speed AC conditions.

Programming uses VPP = 12.75V ±0.25V, VCC = 6.25V ±0.25V, and 100µs/word pulses under PRESTO II algorithm; verify occurs at same VPP with E high and G low. Electronic signature reads manufacturer code 20h and device code 44h via A9 voltage forcing (11.5–12.5V) and A0 toggling.

Key Specifications

Parameter	Value and Actual Design Meaning
Memory Size	4 Mbit (256K words × 16 bits) - supports full 16-bit data bus microprocessor systems without byte-lane splitting.
Access Time	45 ns - enables direct interface with 10 MHz Z80, 80C86, or 68000-class CPUs in wait-state-free operation.
Supply Voltage (Read)	5 V ±10% - compatible with standard TTL/CMOS logic rails; no auxiliary voltage required for read functionality.
Active Current	70 mA at 10 MHz - defines decoupling requirement: 0.1 µF ceramic cap per device + 4.7 µF bulk cap per 8 devices.
Standby Current	100 µA - achieved when E = VIH; ensures low-power retention during CPU idle cycles in embedded controllers.
Programming Voltage	VPP = 12.75 V ±0.25 V - requires dedicated HV supply; incompatible with standard 5V-only programmers unless equipped with charge pump.
Electronic Signature	Manufacturer Code 20h, Device Code 44h - enables automatic algorithm selection in universal EPROM programmers (e.g., Data I/O PS-300).

Pinout & Package

Package: PLCC44 (Plastic Leaded Chip Carrier, 44-lead, JEDEC MO-047AC), 16.6 mm × 16.6 mm body, 1.7 mm height, gull-wing leads, RoHS-compliant ECOPACK® finish.

Pin/Terminal	Circuit Role	Design Meaning
A0–A17	Address Inputs	18-bit address bus supporting 256K-word addressing; A16/A17 unconnected in 256K×16 configuration but present for pin compatibility.
Q0–Q15	Data Outputs	16-bit bidirectional data bus - outputs only; driven low/high during read, high-impedance in standby or program-inhibit.
E	Chip Enable	Primary device select; VIH places device in standby (100 µA), VIL enables read/program operations.
G	Output Enable	Secondary output gate; VIL enables Q0–Q15 drivers, VIH forces high-impedance regardless of E state.
VPP	Programming Supply	12.75 V input required only during programming/verify; must be stable before and after VCC sequencing.
VCC	Power Supply	5 V for read, 6.25 V for programming - strict sequencing (VCC before VPP, remove VCC after VPP) prevents latch-up.
VSS	Ground	Two dedicated ground pins (pins 23 and 34) - reduces ground bounce in high-speed 16-bit bus transitions.
NC	No Connect	Pins 12, 22, 33, 44 are internally unconnected - must remain floating or tied to VSS per layout guidelines.

Key Features

Feature	Design Value
Two-line output control (E/G)	Enables zero-bus-contention memory arrays: E selects device into active/standby, G gates outputs - critical for multi-chip ROM banks.
PRESTO II programming algorithm	Guarantees cell margin with auto-verify at elevated VCC (6.25 V); eliminates overprogramming and extends data retention beyond 10 years.
Electronic Signature (20h/44h)	Allows fully automated device identification in production programmers - eliminates manual algorithm selection errors during firmware burn-in.
UV-erasable architecture	Supports unlimited reprogramming via 2537 Å UV exposure (15–20 min); essential for development, qualification, and field firmware updates.
ECOPACK® lead-free packaging	Meets JEDEC JESD97 second-level interconnect marking; enables compliance with RoHS directives in legacy system re-manufacturing.

Applications

Industrial PLC Firmware Storage

Legacy Automotive ECU Boot ROM

Use Scenario: Storing fixed ladder logic and I/O mapping in DIN-rail mounted programmable logic controllers deployed in factory automation environments.

IC Role / Device Role / Timing Role: Nonvolatile boot memory holding initialization code executed by 80C186 derivative MCU on power-up; accessed at 5 MHz with no wait states.

Use Value: UV erasability allows firmware revision during commissioning or field service without PCB replacement; PLCC44 socket compatibility simplifies rework.

Use Scenario: Holding engine calibration tables and startup routines in pre-OBD-II automotive engine control units manufactured between 1995–2005.

IC Role / Device Role / Timing Role: Primary 16-bit ROM interfaced directly to Motorola 68HC11 address/data bus; 45ns access ensures deterministic boot timing within 100 ms safety window.

Use Value: Electronic signature (20h/44h) enables automated verification during ECU reflash validation, preventing mismatched firmware loads.

Military Avionics Boot Loader

Medical Imaging System BIOS

Use Scenario: Storing secure bootloader and FPGA configuration bitstreams in airborne mission computers requiring radiation-tolerant firmware persistence.

IC Role / Device Role / Timing Role: Read-only memory mapped at reset vector; accessed under MIL-STD-810F temperature cycling (–40°C to +85°C) with guaranteed 45ns timing.

Use Value: Standby current of 100 µA minimizes quiescent power in battery-backed hold modes during aircraft ground maintenance.

Use Scenario: Hosting diagnostic self-test routines and hardware initialization sequences in CT scanner mainboards where firmware integrity is FDA-critical.

IC Role / Device Role / Timing Role: EPROM-based BIOS executing prior to DRAM initialization; relies on two-line control (E/G) to avoid bus contention with peripheral controllers during POST.

Use Value: ECOPACK® lead-free PLCC44 package satisfies medical device environmental compliance (IEC 60601-1) without compromising legacy board layout.

Equivalent & Alternatives

The following parts are listed as comparable options for similar UV-erasable EPROM applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
AM27C4002-12DC	Same 4 Mbit ×16 architecture, 45ns access, but offered in PDIP40 (not PLCC44); VPP tolerance ±0.5V vs. ±0.25V.	Requires through-hole PCB footprint and socket; lacks ECOPACK® marking; not suitable for surface-mount rework scenarios.	Select when replacing legacy DIP-based designs with identical pinout and no space constraints.
AT27C4002-12JC	Pin-compatible PLCC44 variant with identical timing, but uses Atmel's proprietary programming algorithm and signature codes (1Fh/44h).	Requires firmware update to programmer software; verified 20-year data retention vs. ST's 10-year spec; higher VPP noise immunity.	Select for long-life medical/military deployments where extended data retention outweighs toolchain revalidation cost.

Compared with AM27C4002-12DC and AT27C4002-12JC, the M27C4002-12C1 uniquely combines ECOPACK® compliance, ST-specific PRESTO II margin guarantee, and seamless integration into existing PLCC44 socketed test fixtures without algorithm changes.

Availability

M27C4002-12C1 is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy automotive ECU boot ROM, and military avionics boot loader applications requiring stable component supply across extended product lifecycles.

Supply support for M27C4002-12C1 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, designing and manufacturing analog, microcontroller, power, and memory products for industrial, automotive, and consumer markets.

The M27C4002 belongs to ST's legacy EPROM product line, engineered specifically for high-reliability, UV-erasable firmware storage in microprocessor-based systems where long-term data retention and field-programmability are mandatory.

FAQ

What UV wavelength and exposure time are required to erase the M27C4002-12C1?

The M27C4002-12C1 requires short-wave ultraviolet light at 2537 Å wavelength. Erasure needs a minimum integrated dose of 15 W·sec/cm² - achievable in 15–20 minutes using a 12,000 µW/cm² lamp with the device placed within 2.5 cm of the source. Fluorescent lighting causes slow erasure (≈3 years), so opaque window labels are recommended for long-term storage.

Can the M27C4002-12C1 be programmed with a standard 5V-only EPROM programmer?

No. Programming requires VPP = 12.75 V ±0.25 V and VCC = 6.25 V ±0.25 V simultaneously - voltages incompatible with 5V-only programmers. A dedicated high-voltage programmer supporting PRESTO II algorithm (e.g., BP Microsystems Model 3000) or ST-approved equipment is mandatory. Attempting programming at 5V will fail silently.

Is the PLCC44 package of M27C4002-12C1 RoHS-compliant?

Yes. The M27C4002-12C1 carries ST's ECOPACK® designation, confirming lead-free terminations and compliance with RoHS Directive 2011/65/EU. JEDEC JESD97 second-level interconnect marking is present on the package body and inner box label, with soldering profiles validated per IPC/JEDEC J-STD-020.

How does the two-line control (E and G) prevent bus contention in multi-EPROM systems?

E (Chip Enable) places deselected devices in 100 µA standby mode with outputs in high-impedance, while G (Output Enable) independently gates active-device outputs. This decouples selection from output drive - ensuring only one device drives the 16-bit bus at any time, even during partial address decode or fast switching, eliminating contention-induced signal corruption.

M27C4002-12C1 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 44-LCC (J-Lead)

Packaging:: Tube

Product Status:: Obsolete

Programmable:: Not Verified

Memory Type:: Non-Volatile

Memory Format:: EPROM

Technology:: EPROM - OTP

Memory Size:: 4Mbit

Memory Organization:: 256K x 16

Memory Interface:: Parallel

Clock Frequency:: -

Write Cycle Time - Word, Page:: -

Access Time:: 120 ns

Voltage - Supply:: 4.5V ~ 5.5V

Operating Temperature:: 0°C ~ 70°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 44-PLCC (16.59x16.59)

M27C4002-12C1 FAQ

1.How can I place an order for M27C4002-12C1 through Aetrix?

Please submit a Request for Quotation (RFQ) for M27C4002-12C1 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 M27C4002-12C1 reliable?

The price and inventory of M27C4002-12C1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for M27C4002-12C1 is usually 5 days.

3.What payment methods are accepted for M27C4002-12C1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for M27C4002-12C1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for M27C4002-12C1?

M27C4002-12C1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your M27C4002-12C1 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 M27C4002-12C1?

For technical support, including M27C4002-12C1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your M27C4002-12C1 requirements.

6.How does Aetrix verify that M27C4002-12C1 is sourced from the original manufacturer or authorized distributors?

All M27C4002-12C1 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 M27C4002-12C1 meets industry standards.

7.What is the process for return or replacement of M27C4002-12C1?

All M27C4002-12C1 units undergo pre-shipment inspection (PSI). If there is an issue with M27C4002-12C1, 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 M27C4002-12C1 part is unused and in its original packaging.

Return procedure for M27C4002-12C1:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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