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Microchip Technology AT27C040-12PI
- Part No.:
- AT27C040-12PI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-DIP (0.600", 15.24mm)
- Datasheet:
-
AT27C040-12PI.pdf
- Description:
- IC EPROM 4MBIT PARALLEL 32DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,850
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Product details
Overview
AT27C040-12PI from Atmel is a 4-Mbit (512K × 8) one-time programmable EPROM with 120 ns maximum read access time, 5V ±10% supply operation, and industrial temperature range (–40°C to +85°C). It features dual-line control (CE/OE), CMOS/TTL-compatible I/O, and rapid programming at 100 µs/byte - used in legacy microprocessor boot memory and firmware storage applications.
For engineers reviewing the AT27C040-12PI datasheet, AT27C040-12PI pinout, AT27C040-12PI application, or AT27C040-12PI equivalent, key selection criteria include verified 120 ns tACC timing, PLCC-32 packaging, VPP = 12.0 V ±0.5 V programming voltage, 100 µA max standby current, and compatibility with industry-standard EPROM programmers supporting Rapid™ algorithm.
Technical Context
The AT27C040-12PI implements a standard OTP EPROM architecture with address decoding for A0–A18 (19-bit addressing), 8-bit parallel data outputs (O0–O7), and two active-low control lines: Chip Enable (CE) and Output Enable (OE). Its internal logic supports read, standby, rapid program, and product identification modes via dedicated VPP and A9 voltage sequencing.
It uses Atmel's scaled CMOS process to achieve low power consumption (≤100 µA standby, ≤30 mA active at 5 MHz) and high reliability (2000V ESD protection, 200 mA latchup immunity). The integrated product identification code (Manufacturer ID = 0x1E, Device ID = 0x0B) enables automatic algorithm selection in compatible programmers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4,194,304 bits (512K × 8) - supports full 19-bit address space for boot ROM or firmware image storage |
| Read Access Time | 120 ns max (tACC) - eliminates WAIT states in 8/16-bit microprocessor systems running ≤8.3 MHz |
| Supply Voltage | 5V ±10% - compatible with standard TTL/CMOS logic rails without regulation |
| Standby Current | 100 µA max - enables low-power retention in always-on embedded control modules |
| Programming Voltage | VPP = 12.0 V ±0.5 V - requires external high-voltage supply during programming; not used in read mode |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade environmental stress and thermal cycling |
| Input Compatibility | CMOS and TTL - accepts 0.8 V VIH min and 2.0 V VIH min logic levels, simplifying interface with mixed-signal controllers |
Pinout & Package
AT27C040-12PI is packaged in a 32-lead Plastic J-Leaded Chip Carrier (PLCC-32), JEDEC MS-016 compliant, with pin 1 identifier corner and gull-wing leads. Package dimensions: 12.5 mm × 15.1 mm × 3.6 mm (max height).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit parallel address bus; fully decoded internally to select one of 524,288 bytes |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus in read mode; high-impedance when CE or OE inactive |
| CE | Chip Enable | Active-low global enable; must be low before OE to avoid bus contention in multi-device systems |
| OE | Output Enable | Active-low output gate; allows shared data bus usage with other peripherals without external tri-state logic |
| VPP | Programming Voltage | 12.0 V input required only during programming; must be applied after VCC and removed before VCC |
| VCC | Power Supply | +5 V main supply; powers all logic and output drivers during read and program operations |
| GND | Ground Reference | Common return path for VCC and VPP; requires local 0.1 µF ceramic decoupling per device |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time - reduces firmware update cycle time by >90% vs. legacy EPROM algorithms |
| Integrated Product ID Code | Manufacturer ID = 0x1E, Device ID = 0x0B - enables auto-detection and voltage/algorithm selection in certified programmers |
| Dual-Line Control (CE/OE) | Independent chip and output gating - prevents bus contention and supports interleaved memory access in high-speed systems |
| High-Reliability CMOS Process | 2000 V HBM ESD rating and 200 mA latchup immunity - ensures robustness in manufacturing handling and field deployment |
| JEDEC-Standard PLCC Packaging | 32J footprint - enables drop-in replacement for other 32-pin PLCC EPROMs and compatibility with existing socket/tooling |
Applications
| Industrial PLC Firmware Storage | Legacy Microcontroller Boot ROM |
|---|---|
Use Scenario: Storing fixed ladder logic and I/O configuration in programmable logic controllers deployed in factory automation environments. IC Role / Device Role / Timing Role: Nonvolatile boot memory holding initialization code executed on power-up; accessed sequentially during reset vector fetch. Use Value: 120 ns tACC ensures no wait-state insertion for 80C188/80C186-based controllers, maintaining deterministic startup timing. | Use Scenario: Providing immutable startup firmware for 8-bit and 16-bit microcontrollers in medical diagnostic equipment where firmware integrity is critical. IC Role / Device Role / Timing Role: Primary read-only instruction memory mapped to CPU address space; enabled via dedicated CE line tied to address decoder. Use Value: Industrial temperature rating (–40°C to +85°C) guarantees reliable operation across clinical environment thermal cycles. |
| Automotive Engine Control Unit Calibration Data | Test Equipment Configuration Memory |
Use Scenario: Holding engine calibration maps and lookup tables in pre-OBD-II automotive ECUs where reprogramming is infrequent and security is not required. IC Role / Device Role / Timing Role: Static data repository accessed randomly during sensor interpolation routines; CE asserted during map reads. Use Value: 5V ±10% supply tolerance accommodates vehicle battery voltage fluctuations without external regulation. | Use Scenario: Storing instrument-specific setup parameters and self-test sequences in benchtop oscilloscopes and signal generators. IC Role / Device Role / Timing Role: Configuration ROM mapped to controller's peripheral address space; read during power-on self-test (POST). Use Value: 100 µA max standby current minimizes quiescent drain on backup batteries used for real-time clock and settings retention. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C040-12DC | Same 4-Mbit size, 120 ns speed, and PLCC-32 package; requires VPP = 12.5 V ±0.5 V (vs. 12.0 V for AT27C040-12PI) | Identical industrial temperature range and pinout; validated in AMD-compatible programmers only | Select if using AMD-certified programming hardware or requiring tighter VPP tolerance margin |
| MX27C4001-12PC | 4-Mbit OTP EPROM in PDIP-32; 120 ns access, but uses VPP = 12.5 V and lacks integrated product ID code | Requires manual algorithm selection in programmer; not suitable for automated production lines relying on ID-based detection | Choose for cost-sensitive, low-volume hand-programming where socket compatibility with DIP-32 is preferred |
Compared with AM27C040-12DC and MX27C4001-12PC, the AT27C040-12PI offers guaranteed Rapid™ algorithm support, built-in ID code for plug-and-play programming, and lower VPP tolerance (±0.5 V), reducing high-voltage supply design complexity in automated test fixtures.
Availability
AT27C040-12PI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy microcontroller boot ROM, and automotive ECU calibration data applications requiring stable component supply and long-term obsolescence management.
Supply support for AT27C040-12PI 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 was a U.S.-based semiconductor manufacturer specializing in microcontrollers, nonvolatile memory, and RF solutions before its acquisition by Microchip Technology in 2016.
The AT27C040-12PI belongs to Atmel's OTP EPROM product line, designed specifically for cost-effective, high-reliability firmware and configuration storage in industrial and automotive systems where field reprogrammability is unnecessary.
FAQ
What is the maximum operating frequency supported by the AT27C040-12PI in read mode?
The AT27C040-12PI does not specify a maximum operating frequency directly, but its 120 ns access time (tACC) implies reliable operation up to approximately 8.3 MHz in systems with zero wait states. This is derived from the inverse of tACC (1/120 ns ≈ 8.3 MHz). The AT27C040-12PI is intended for use with microprocessors such as the 80C186 or 68000 family where address-to-data timing is the limiting factor, not clock frequency itself.
Does the AT27C040-12PI require an external capacitor on the VPP pin during programming?
Yes, a 0.1 µF ceramic capacitor is required between VPP and GND during programming of the AT27C040-12PI to suppress spurious voltage transients that could cause programming errors. This capacitor must be placed as close as possible to the VPP and GND pins. The AT27C040-12PI datasheet explicitly mandates this in the Programming Waveforms section and notes it as essential for reliable 100 µs pulse application.
Can the AT27C040-12PI be used interchangeably with the AT27C040-12JC in the same PCB layout?
No - the AT27C040-12PI uses a PLCC-32 package (32J), while the AT27C040-12JC uses a PDIP-32 package (32P6); their footprints and mounting methods are mechanically incompatible. Although both share identical electrical specifications and pin functions, the AT27C040-12PI requires a PLCC socket or reflow-compatible land pattern, whereas the AT27C040-12JC needs through-hole or gull-wing SMT pads for PDIP. The AT27C040-12PI cannot be substituted without PCB revision.
What is the purpose of the A9 pin during product identification mode on the AT27C040-12PI?
During product identification mode, the A9 pin of the AT27C040-12PI is driven to VH = 12.0 V ±0.5 V to activate the internal ID register. With A0 toggled and all other address lines held low, this enables serial readout of the Manufacturer ID byte (0x1E) and Device ID byte (0x0B) on O7–O0. This feature allows automated programming equipment to verify part authenticity and select correct programming algorithms before initiating write cycles on the AT27C040-12PI.
Is the AT27C040-12PI still recommended for new designs?
The AT27C040-12PI is an obsolete OTP EPROM no longer recommended for new designs due to discontinuation by Microchip (post-Atmel acquisition) and lack of modern alternatives with equivalent density and industrial qualification. However, Aetrix Electronics maintains active inventory and lifecycle support for legacy system repair, maintenance, and obsolescence mitigation. Designers should evaluate flash-based replacements like the SST39VF400A only if reprogrammability, lower voltage, or RoHS compliance are required - the AT27C040-12PI remains valid for sustaining engineering where functional equivalence and mechanical fit are mandatory.
AT27C040-12PI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-DIP (0.600", 15.24mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EPROM
- Technology:
- EPROM - OTP
- Memory Size:
- 4Mbit
- Memory Organization:
- 512K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 120 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 32-PDIP
AT27C040-12PI FAQ
1.How can I place an order for AT27C040-12PI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C040-12PI 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 AT27C040-12PI reliable?
The price and inventory of AT27C040-12PI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C040-12PI is usually 5 days.
3.What payment methods are accepted for AT27C040-12PI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C040-12PI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C040-12PI?
AT27C040-12PI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C040-12PI 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 AT27C040-12PI?
For technical support, including AT27C040-12PI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C040-12PI requirements.
6.How does Aetrix verify that AT27C040-12PI is sourced from the original manufacturer or authorized distributors?
All AT27C040-12PI 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 AT27C040-12PI meets industry standards.
7.What is the process for return or replacement of AT27C040-12PI?
All AT27C040-12PI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C040-12PI, 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 AT27C040-12PI part is unused and in its original packaging.
Return procedure for AT27C040-12PI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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