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Microchip Technology AT27C040-70PU
- Part No.:
- AT27C040-70PU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-DIP (0.600", 15.24mm)
- Datasheet:
-
AT27C040-70PU.pdf
- Description:
- IC EPROM 4MBIT PARALLEL 32DIP
- Quantity:
- Payment:
- Shipping:
Inventory:671
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Product details
Overview
AT27C040-70PU from Atmel is a 4 Mb (512K × 8) One-Time Programmable EPROM with 70 ns read access time, 5 V ±10% single-supply operation, and CMOS/TTL-compatible I/O. It features dual-line control (CE/OE), industrial temperature range (–40°C to +85°C), and JEDEC-standard 32-lead PDIP packaging. Used in legacy microprocessor boot memory, firmware storage, and embedded controller code retention.
For engineers reviewing the AT27C040-70PU datasheet, AT27C040-70PU pinout, AT27C040-70PU application, or AT27C040-70PU equivalent, key selection criteria include verified 70 ns tACC timing, rapid 100 μs/byte programming algorithm, VPP = 13.0 V programming voltage, integrated product identification code, and compatibility with standard EPROM programmers supporting 512K×8 OTP devices.
Technical Context
The AT27C040-70PU implements a scalable CMOS OTP EPROM architecture with address decoding across A0–A18 (19-bit), 8-bit bidirectional data outputs O0–O7, and dedicated VPP pin for high-voltage programming. Its two-line enable logic (CE/OE) enables bus contention avoidance in multiplexed memory systems.
It supports four distinct operational modes: Read (CE=OE=VIL), Standby (CE=VIH), Rapid Program (CE=VIL, OE=VIH, VPP=13.0 V), and Product Identification (A9=12.0 V, A0 toggled). Programming requires precise 100 μs ±5% CE pulse width and strict VCC/VPP sequencing per datasheet Figure 6-4 and Section 7.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4,194,304 bits (512K × 8); supports full 19-bit address space without banking or wait states. |
| Read Access Time | 70 ns max (tACC); eliminates need for wait states on 14 MHz+ microprocessors. |
| Supply Voltage | 5 V ±10%; operates from single rail-no auxiliary supplies required for read mode. |
| Active Current | 30 mA max at 5 MHz; enables low-power system design with predictable dynamic loading. |
| Standby Current | 100 μA max (ISB1, CMOS CE); reduces quiescent power in idle firmware storage applications. |
| Programming Voltage | VPP = 13.0 V ±0.25 V; requires external high-voltage supply and strict sequencing with VCC. |
| Operating Temp | –40°C to +85°C; qualified for industrial environments including factory automation and instrumentation. |
Pinout & Package
AT27C040-70PU is packaged in a 32-lead, 0.600" wide plastic dual inline package (PDIP), per JEDEC MS-016 variation AE and Atmel drawing 32P6. Pin 1 is marked by notch or dot; leads are matte tin finished.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC | Device Power Supply | Primary 5 V supply; must be applied simultaneously with or before VPP during programming. |
| GND | Ground Reference | Common return for all signals and supplies; requires local 0.1 μF ceramic decoupling. |
| VPP | Programming Voltage Input | 13.0 V input for byte programming; requires external HV source and 0.1 μF capacitor to ground. |
| A0–A18 | Address Inputs | 19-bit address bus; fully decoded to select one of 524,288 bytes; A9 used for ID code selection. |
| O0–O7 | Data Outputs | 8-bit TTL/CMOS-compatible output bus; tri-stated when CE or OE is high. |
| CE | Chip Enable | Active-low chip select; controls device activation and initiates programming pulses (100 μs width). |
| OE | Output Enable | Active-low output gate; enables data bus drive only when CE is also active low. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid Programming Algorithm | 100 μs/byte typical programming time with auto-verify loop; reduces firmware burn time by >5× vs. legacy EPROMs. |
| Integrated Product ID Code | Two-byte electronic ID (0x1E manufacturer, 0x0B device) readable via A9=12 V and A0 toggle; ensures programmer compatibility and traceability. |
| ESD & Latchup Immunity | 2000 V HBM ESD protection and 200 mA latchup immunity; enhances robustness during handling and in-circuit programming. |
| JEDEC Standard Packaging | 32-lead PDIP (32P6) footprint compatible with legacy sockets and automated insertion equipment. |
| Green Packaging Option | Pb/halide-free construction per RoHS; meets environmental compliance for industrial OEM deployments. |
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 floors. IC Role / Device Role / Timing Role: Nonvolatile boot-time code storage with deterministic 70 ns read latency ensuring real-time scan cycle integrity. Use Value: Eliminates reliance on volatile RAM and external refresh circuitry; withstands repeated power cycling without data loss. |
Use Scenario: Holding startup initialization code and peripheral drivers for 8/16-bit microcontrollers in medical analyzers and test equipment. IC Role / Device Role / Timing Role: Primary ROM executing immediately after reset; synchronized to system clock via CE/OE timing margins. Use Value: Guarantees sub-70 ns instruction fetch latency, enabling tight timing budgets in safety-critical boot sequences. |
| Automated Test Equipment (ATE) Pattern Memory | Avionics Maintenance Diagnostic Module |
|
Use Scenario: Storing digital stimulus/response patterns for semiconductor wafer probing and functional testing. IC Role / Device Role / Timing Role: High-speed parallel memory accessed by pattern generator ASICs using burst-mode addressing. Use Value: 30 mA active current and 100 μA standby support thermal stability during long test cycles with minimal cooling overhead. |
Use Scenario: Retaining aircraft-specific calibration tables and fault-decoding logic in portable line-replaceable maintenance units. IC Role / Device Role / Timing Role: Radiation-tolerant (non-flash) firmware store operating across –40°C to +85°C ambient without derating. Use Value: Industrial temp grade and 200 mA latchup immunity ensure reliability in electrically noisy avionics bays. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C040-70DC | 4 Mb OTP EPROM with identical 70 ns tACC, but uses AMD's proprietary programming algorithm and lacks integrated ID code. | Requires AMD-specific programmers; no A9-based ID readback-limits automated programming line integration. | Select when existing AMD toolchain is in place and ID verification is not required. |
| MX27C4001-70PC | 4 Mb OTP EPROM with same pinout and 70 ns speed, but rated for commercial temp (0°C to +70°C) only. | Not qualified for industrial environments; standby current rises to 500 μA above +70°C. | Acceptable only for cost-sensitive non-industrial applications where extended temperature operation is unnecessary. |
Compared with AM27C040-70DC and MX27C4001-70PC, the AT27C040-70PU uniquely combines industrial temperature rating, integrated product ID code, and Atmel's standardized rapid programming algorithm-making it the preferred choice for new designs requiring field-programmable firmware storage with traceability and broad toolchain support.
Availability
AT27C040-70PU is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy microcontroller boot ROM, and automated test equipment pattern memory requiring stable component supply and long-term obsolescence management.
Supply support for AT27C040-70PU 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 company specializing in microcontrollers, nonvolatile memory, and programmable logic, later acquired by Microchip Technology in 2016.
The AT27C040-70PU belongs to Atmel's OTP EPROM product line, designed specifically for reliable, low-cost, field-programmable firmware storage in industrial and instrumentation systems where flash endurance or reprogrammability is unnecessary.
FAQ
What is the programming voltage requirement for AT27C040-70PU?
The AT27C040-70PU requires VPP = 13.0 V ±0.25 V during programming, applied simultaneously with or after VCC = 6.5 V ±0.25 V. This high-voltage supply is mandatory for oxide breakdown during byte programming and must be sequenced per Figure 6-4 and Section 7 of the datasheet. The AT27C040-70PU does not support in-system programming without dedicated EPROM programmer hardware.
Does AT27C040-70PU support read-modify-write operations?
No, the AT27C040-70PU is a One-Time Programmable EPROM and does not support read-modify-write operations. Once programmed, its contents are permanent and cannot be electrically erased or rewritten. Any modification requires physical replacement of the AT27C040-70PU device. This architecture ensures data immutability critical for certified firmware deployments.
How is the product identification code accessed on AT27C040-70PU?
The AT27C040-70PU product identification code is accessed by setting A9 = 12.0 V (VID = 11.5–12.5 V), holding A1–A18 = VIL, and toggling A0 between VIL (to read manufacturer ID 0x1E) and VIH (to read device ID 0x0B). This two-byte electronic signature is used by industry-standard programmers to auto-detect the AT27C040-70PU and select correct algorithms.
What decoupling capacitors are required for stable AT27C040-70PU operation?
Each AT27C040-70PU requires a 0.1 μF high-frequency ceramic capacitor placed between VCC and GND, mounted as close to the device pins as possible. For boards with multiple AT27C040-70PU devices, a 4.7 μF bulk electrolytic capacitor must also be placed near the power entry point to stabilize the VCC rail and suppress transient excursions caused by CE switching.
Is AT27C040-70PU pin-compatible with other 32-lead EPROMs like 27C4001?
The AT27C040-70PU shares the same 32-lead PDIP (32P6) mechanical footprint and pinout as industry-standard 4 Mb EPROMs including the 27C4001, but differs electrically in programming voltage (13.0 V vs. 12.5 V) and ID code access method. While socket-compatible, direct substitution requires validation of VPP tolerance, timing margins, and programmer firmware-AT27C040-70PU is not a drop-in replacement without system-level verification.
AT27C040-70PU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-DIP (0.600", 15.24mm)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- 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:
- 70 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
AT27C040-70PU FAQ
1.How can I place an order for AT27C040-70PU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C040-70PU 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 AT27C040-70PU reliable?
The price and inventory of AT27C040-70PU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C040-70PU is usually 5 days.
3.What payment methods are accepted for AT27C040-70PU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C040-70PU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C040-70PU?
AT27C040-70PU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C040-70PU 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 AT27C040-70PU?
For technical support, including AT27C040-70PU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C040-70PU requirements.
6.How does Aetrix verify that AT27C040-70PU is sourced from the original manufacturer or authorized distributors?
All AT27C040-70PU 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 AT27C040-70PU meets industry standards.
7.What is the process for return or replacement of AT27C040-70PU?
All AT27C040-70PU units undergo pre-shipment inspection (PSI). If there is an issue with AT27C040-70PU, 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 AT27C040-70PU part is unused and in its original packaging.
Return procedure for AT27C040-70PU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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