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Microchip Technology AT27C040-70JU-T
- Part No.:
- AT27C040-70JU-T
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT27C040-70JU-T.pdf
- Description:
- IC EPROM 4MBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:649
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Product details
Overview
AT27C040-70JU-T from Atmel is a 4 Mb (512K × 8) One-Time Programmable EPROM with 70 ns read access time, 5V ±10% supply, and industrial temperature range (−40°C to +85°C). It features CMOS/TTL-compatible I/O, dual-line control (CE/OE), and JEDEC-standard 32-lead PLCC packaging. Used in legacy microprocessor boot memory and firmware storage where non-volatility and program-once reliability are critical.
For engineers reviewing the AT27C040-70JU-T datasheet, AT27C040-70JU-T pinout, AT27C040-70JU-T application, or AT27C040-70JU-T equivalent, key selection criteria include verified 70 ns tACC timing, VPP = 12–13 V programming voltage, rapid 100 μs/byte programming algorithm, and compatibility with industry-standard EPROM programmers supporting product identification code (0x1E/0x0B).
Technical Context
The AT27C040-70JU-T implements a high-reliability CMOS OTP EPROM architecture with address decoding (A0–A18), output buffering (O0–O7), and integrated product identification logic. Its two-line enable scheme (CE and OE) enables bus contention avoidance in 8-bit microprocessor systems operating at up to 5 MHz.
Programming requires VPP = 13.0 V ±0.25 V and VCC = 6.5 V ±0.25 V, with a deterministic 100 μs CE pulse width and verification loop per byte. The device supports manufacturer/device ID readout via A9 = 12 V and A0 toggling, enabling automated programmer recognition.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4,194,304 bits (512K × 8); supports full 19-bit addressing for boot ROM in 8-bit embedded controllers. |
| Read access time | 70 ns max (tACC); eliminates wait states on Z80, 8086, and 68000-based systems running ≤14 MHz. |
| Supply voltage | 5 V ±10%; operates directly from standard logic rail without regulation-reduces BOM count. |
| Standby current | 100 μA max (ISB1); enables low-power retention in always-on industrial control modules. |
| Active current | 30 mA max at 5 MHz (ICC); compatible with legacy power budgets and linear regulators. |
| Programming voltage | VPP = 12.0–13.0 V; requires dedicated high-voltage supply or programmer with VPP boost-non-5V compatible. |
| Operating temperature | −40°C to +85°C; qualified for industrial environments including PLC backplanes and motor drives. |
Pinout & Package
AT27C040-70JU-T is packaged in a 32-lead plastic J-leaded chip carrier (PLCC), JEDEC MS-016 variant AE, with lead finish matte tin. Pin 1 identifier located at corner with 45° chamfer.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC | Power supply input | 5 V main supply; must be applied simultaneously with or before VPP during programming. |
| GND | Ground reference | Common return for all signals; decoupling capacitor (0.1 μF ceramic) required adjacent to pin. |
| VPP | Programming voltage input | 12–13 V input only during programming; floating or tied to VCC during read mode. |
| A0–A18 | Address inputs | 19-bit address bus; A9 used with VPP for product ID readout (12 V level required). |
| O0–O7 | Data outputs | 8-bit bidirectional data bus in read mode; high-impedance when CE or OE inactive. |
| 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 drivers independently of CE for bus sharing. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid programming algorithm | 100 μs/byte typical; reduces firmware update time by >90% vs. legacy EPROMs requiring ms-level pulses. |
| Integrated product ID code | Manufacturer ID = 0x1E, Device ID = 0x0B; enables automatic algorithm selection in universal programmers. |
| ESD and latchup immunity | 2000 V HBM ESD rating and 200 mA latchup immunity; ensures robustness during manual handling and board insertion. |
| JEDEC-standard packaging | 32-lead PLCC (32J); drop-in replacement for other 512K×8 EPROMs in existing sockets and PCB footprints. |
| CMOS/TTL interface compatibility | VIL ≤ 0.8 V, VIH ≥ 2.0 V; interoperable with both CMOS and bipolar logic families without level shifters. |
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 cabinets. IC Role / Device Role / Timing Role: Non-volatile boot memory mapped to CPU address space; accessed during power-up reset sequence with strict 70 ns timing compliance. Use Value: Eliminates need for battery-backed SRAM or EEPROM wear leveling; guarantees firmware integrity over 20+ year service life. | Use Scenario: Providing immutable startup code for Z80- or 8051-based instrumentation systems where field reprogramming is prohibited. IC Role / Device Role / Timing Role: Primary instruction ROM executing from reset vector; timing-critical for system initialization within 1–2 μs of power stabilization. Use Value: Prevents accidental corruption during operation; no risk of bit flips under EMI or voltage droop due to OTP architecture. |
| Military Avionics Configuration Memory | Medical Device Calibration Data |
Use Scenario: Holding flight control parameter tables and sensor calibration constants in certified airborne electronics with DO-254 traceability requirements. IC Role / Device Role / Timing Role: Read-only configuration store accessed during Built-In Test (BIT); requires guaranteed data retention across −55°C to +125°C storage. Use Value: Meets MIL-STD-883 Class B screening; no latent failure modes from write cycles-critical for safety-critical validation. | Use Scenario: Storing factory-calibrated ADC offset/gain coefficients and safety interlock thresholds in Class II medical analyzers. IC Role / Device Role / Timing Role: Secure, tamper-proof memory element read once per power cycle; immune to software overwrite or malware injection. Use Value: Satisfies IEC 62304 §5.5.3 requirement for immutable configuration data; eliminates audit trail for firmware modification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C040-70PU | Same die, 32-lead PDIP package; 0.600" width; no J-leads; higher thermal resistance. | Suitable for through-hole prototyping or legacy wave-soldered boards; not socket-compatible with PLCC. | Select AT27C040-70PU only when PDIP footprint and hand-soldering are required-no electrical difference. |
| AM27C040-70DC | AMD second-source version; identical timing (70 ns), same pinout, but VPP tolerance ±0.5 V tighter (12.0 ±0.5 V). | Validated in aerospace programs where multi-source procurement is mandated; identical functional behavior. | Choose AM27C040-70DC when dual-sourcing is contractually required-no design change needed. |
Compared with AT27C040-70JU-T, the AT27C040-70PU offers identical functionality in PDIP for through-hole use, while AM27C040-70DC provides a fully pin- and function-compatible second source with tighter VPP specification-both preserve the 70 ns read timing and OTP security model without layout or firmware changes.
Availability
AT27C040-70JU-T is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy microcontroller boot ROM, military avionics configuration memory, and medical device calibration data applications requiring stable component supply and long-term obsolescence management.
Supply support for AT27C040-70JU-T 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, non-volatile memory, and analog products before its acquisition by Microchip Technology in 2016.
The AT27C040 belongs to Atmel's OTP EPROM product line, designed specifically for secure, unalterable firmware and configuration storage in industrial, military, and medical systems where data integrity and long-term reliability outweigh reprogrammability.
FAQ
What is the programming voltage requirement for AT27C040-70JU-T?
The AT27C040-70JU-T requires VPP = 13.0 V ±0.25 V during programming, applied simultaneously with VCC = 6.5 V ±0.25 V. VPP must be removed after programming completes and may be tied to VCC during normal read operation. This high-voltage requirement mandates use of a dedicated EPROM programmer capable of generating and sequencing these supplies-standard 5 V-only programmers cannot program the AT27C040-70JU-T.
Does AT27C040-70JU-T support in-system programming?
No, the AT27C040-70JU-T does not support in-system programming. It requires removal from the target board and insertion into a dedicated EPROM programmer with VPP capability. The device lacks serial interfaces, command protocols, or internal charge pumps needed for ISP. Programming must occur in a controlled environment using verified algorithms that apply 100 μs CE pulses and perform byte-by-byte verification-making field updates impractical.
What is the meaning of the "JU" suffix in AT27C040-70JU-T?
The "JU" suffix in AT27C040-70JU-T denotes the 32-lead PLCC package (32J) with matte tin lead finish and industrial temperature grade (−40°C to +85°C). The "-T" indicates tape-and-reel packaging for automated assembly. This distinguishes it from the PDIP version (AT27C040-70PU) and confirms JEDEC MS-016 compliance, green (Pb/halide-free) construction, and suitability for surface-mount reflow processes.
Can AT27C040-70JU-T be used as a direct replacement for AT27C040-90JU?
Yes, the AT27C040-70JU-T is a speed-grade upgrade over the AT27C040-90JU, offering 70 ns access time versus 90 ns. Both share identical pinout, voltage requirements, programming algorithm, and package. Systems designed for the -90 version will operate more reliably at higher clock speeds with the -70 variant, though no hardware or firmware changes are needed-the faster timing simply improves margin in timing-critical microprocessor buses.
How is the product identification code read from AT27C040-70JU-T?
The product identification code of AT27C040-70JU-T is read by applying VPP = 12.0 V to A9 while holding A1–A18 low, then toggling A0: A0 = low reads manufacturer ID (0x1E), A0 = high reads device ID (0x0B). CE and OE must both be low. This mode is supported by all compliant EPROM programmers and enables automatic detection of the AT27C040-70JU-T versus other 4 Mb EPROMs during programming setup.
AT27C040-70JU-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 70 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (11.43x13.97)
AT27C040-70JU-T FAQ
1.How can I place an order for AT27C040-70JU-T through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C040-70JU-T 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 AT27C040-70JU-T reliable?
The price and inventory of AT27C040-70JU-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C040-70JU-T is usually 5 days.
3.What payment methods are accepted for AT27C040-70JU-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C040-70JU-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C040-70JU-T?
AT27C040-70JU-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C040-70JU-T 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 AT27C040-70JU-T?
For technical support, including AT27C040-70JU-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C040-70JU-T requirements.
6.How does Aetrix verify that AT27C040-70JU-T is sourced from the original manufacturer or authorized distributors?
All AT27C040-70JU-T 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 AT27C040-70JU-T meets industry standards.
7.What is the process for return or replacement of AT27C040-70JU-T?
All AT27C040-70JU-T units undergo pre-shipment inspection (PSI). If there is an issue with AT27C040-70JU-T, 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 AT27C040-70JU-T part is unused and in its original packaging.
Return procedure for AT27C040-70JU-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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