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Microchip Technology AT27C040-12TI
- Part No.:
- AT27C040-12TI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-TFSOP (0.724", 18.40mm Width)
- Datasheet:
-
AT27C040-12TI.pdf
- Description:
- IC EPROM 4MBIT PARALLEL 32TSOP
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
AT27C040-12TI from Atmel is a 4-Mbit (512K × 8) one-time programmable EPROM with 120 ns read access time, 5V ±10% supply, 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 where non-volatility and pin-level compatibility with older ROM families are required.
For engineers reviewing the AT27C040-12TI datasheet, AT27C040-12TI pinout, AT27C040-12TI application, or AT27C040-12TI equivalent, key selection criteria include verified 120 ns tACC timing, VPP = 12.0 V programming voltage, PLCC-32/TSOP-32/PDIP-32 package options, industrial-grade reliability (200 mA latchup immunity, 2000 V ESD), and OTP configuration for secure firmware deployment without reprogrammability.
Technical Context
The AT27C040-12TI implements a standard OTP EPROM architecture with address decoding across 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 read operation requires only a single 5V supply, eliminating need for auxiliary voltages during normal access.
Programming uses a dedicated 12.0 V ±0.5 V VPP supply applied to pin 1, with Rapid™ algorithm executing 100 µs CE pulses per byte and automatic verify-reprogram loops. Product identification is accessed via A9 = 12.0 V and A0 toggling, returning manufacturer code 0x1E and device code 0x0B - enabling automated programmer recognition.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4,194,304 bits (512K × 8) - supports full 19-bit address space for boot code or fixed firmware images |
| Read Access Time (tACC) | 120 ns max - ensures compatibility with 8 MHz Z80, 68000, and early x86 systems without wait states |
| Supply Voltage | 5V ±10% - operates directly from standard logic rail; no voltage translation needed |
| Standby Current | 100 µA max - enables low-power retention in always-on embedded controllers |
| VPP Programming Voltage | 12.0 V ±0.5 V - requires external high-voltage source; not derived from VCC |
| Operating Temperature | −40°C to +85°C - qualified for industrial environments including factory automation and telecom line cards |
| ESD/Latchup Rating | 2000 V HBM ESD, 200 mA latchup immunity - meets JEDEC JESD22-A114 and JESD78 requirements |
Pinout & Package
AT27C040-12TI is available in three JEDEC-standard packages: 32-lead PLCC (32J), 32-lead PDIP (32P6), and 32-lead TSOP (32T). All variants share identical pin functions and logic behavior.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit address bus interface; A0 = LSB, A18 = MSB; driven by CPU or address latch |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus outputs during read; 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-chip systems |
| OE | Output Enable | Active-low output gate; allows shared data bus usage with other peripherals without tri-state conflicts |
| VPP | Programming Voltage | 12.0 V input during programming only; must be disconnected or tied to VCC (5 V) during read operation |
| VCC | Power Supply | +5 V supply; must be applied simultaneously with or before VPP and removed after VPP |
| GND | Ground Reference | Signal and power ground; requires local 0.1 µF ceramic decoupling capacitor per device |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time with auto-verify loop - reduces production burn-in cycle time by >90% vs. legacy EPROMs |
| Integrated Product ID Code | Manufacturer ID 0x1E and Device ID 0x0B returned via A9=12V/A0 toggle - enables plug-and-play recognition in universal programmers |
| Dual-Line Control (CE/OE) | Independent chip and output enables - eliminates bus contention in high-speed 8/16-bit microprocessor systems with multiple memory devices |
| CMOS/TTL Compatibility | VIL ≤ 0.8 V, VIH ≥ 2.0 V, VOL ≤ 0.4 V, VOH ≥ 2.4 V - interoperates with both CMOS and bipolar logic families without level shifters |
| Industrial Temperature Range | −40°C to +85°C operation - validated for use in motor drives, PLCs, and outdoor telecom equipment |
Applications
| Industrial PLC Firmware Storage | Legacy Microcontroller Boot ROM |
|---|---|
Use Scenario: Storing fixed ladder logic firmware and I/O mapping tables in programmable logic controllers deployed in factory environments with wide ambient temperature swings. IC Role / Device Role / Timing Role: Non-volatile boot memory providing deterministic 120 ns read access to initialization code upon power-up or reset. Use Value: Eliminates need for external voltage translators or wait-state generators due to 5V-only operation and TTL/CMOS compatibility. | Use Scenario: Holding immutable startup routines and peripheral initialization sequences for Z80, 68000, or 8051-based embedded systems in medical analyzers and test equipment. IC Role / Device Role / Timing Role: OTP EPROM acting as primary program memory with guaranteed data retention >10 years under industrial thermal stress. Use Value: Prevents unauthorized firmware modification while maintaining pinout compatibility with obsolete 27C256/27C512 designs. |
| Telecom Line Card Configuration | Avionics System Boot Loader |
Use Scenario: Storing hardware-specific configuration parameters and protocol stacks in DSLAM and optical line terminal line cards operating continuously at elevated temperatures. IC Role / Device Role / Timing Role: Read-only configuration store accessed during cold start; supports hot-swap detection via CE-controlled isolation. Use Value: 200 mA latchup immunity prevents system failure during transient ESD events common in field-replaceable modules. | Use Scenario: Hosting certified boot loader code in airborne communication subsystems requiring DO-254 compliance and long-term data integrity. IC Role / Device Role / Timing Role: Secure, unalterable first-stage bootloader executed before loading application software from flash or EEPROM. Use Value: OTP architecture ensures firmware cannot be overwritten in-flight or during maintenance, meeting safety-critical integrity requirements. |
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 5V supply; but uses AMD's process with 150 µA max standby current vs. 100 µA for AT27C040-12TI | Identical pinout and AC timing; however, product ID codes differ (AMD uses 0x1F/0x0A), requiring programmer configuration update | Select AM27C040-12DC only if existing toolchain supports AMD ID codes and higher standby current is acceptable |
| MX27C4001-12QI | Macronix variant with same 512K×8 organization and 120 ns tACC; differs in VPP tolerance (12.5 V max vs. 12.0 V) and lower 80 µA standby current | PLCC-32 and TSOP-32 packages match; but programming algorithm requires 12.5 V pulse width verification, not supported by all legacy programmers | Choose MX27C4001-12QI when sourcing new production lots and programmer firmware can be updated for Macronix-specific VPP handling |
Compared with AM27C040-12DC and MX27C4001-12QI, the AT27C040-12TI offers the lowest industrial-grade standby current (100 µA), strict 12.0 V VPP compliance matching Atmel-certified programmers, and documented integration into legacy Atmel development ecosystems - making it optimal for drop-in replacement in existing designs.
Availability
AT27C040-12TI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy microcontroller boot ROM, and telecom line card configuration requiring stable component supply across extended product lifecycles.
Supply support for AT27C040-12TI 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 RF solutions before its acquisition by Microchip Technology in 2016.
The AT27C040-12TI belongs to Atmel's OTP EPROM product line, designed specifically for cost-sensitive, high-reliability embedded systems requiring secure, unalterable firmware storage without battery backup or complex write protocols.
FAQ
What is the maximum allowable VPP voltage for programming the AT27C040-12TI?
The AT27C040-12TI requires a precise VPP programming voltage of 12.0 V ±0.5 V during write operations. Exceeding 12.5 V risks permanent damage to the oxide layer, while voltages below 11.5 V may result in incomplete programming or bit errors. This specification is strictly defined in the DC Programming Characteristics table and must be enforced using regulated, low-noise VPP supplies - not derived from VCC. The AT27C040-12TI does not support internal charge pumps or VPP generation.
Does the AT27C040-12TI support in-system programming (ISP)?
No, the AT27C040-12TI does not support in-system programming. It requires removal from the target board and insertion into a dedicated EPROM programmer that applies 12.0 V to the VPP pin and executes the Rapid™ algorithm with 100 µs CE pulses. The device lacks serial interfaces, command protocols, or on-chip state machines needed for ISP - consistent with its OTP EPROM architecture. Programming the AT27C040-12TI must occur in a controlled bench environment prior to soldering.
Can the AT27C040-12TI be used as a direct replacement for the AT27C020 in an existing design?
No, the AT27C040-12TI is not a direct replacement for the AT27C020. While both are Atmel OTP EPROMs with identical pinouts and control signals, the AT27C040-12TI has 19 address lines (A0–A18) versus 18 (A0–A17) on the AT27C020, requiring additional PCB routing for A18 and potentially altering address decoding logic. The AT27C040-12TI also draws higher active current (30 mA vs. 25 mA) and requires stricter VPP regulation. Replacing AT27C020 with AT27C040-12TI necessitates hardware and firmware validation.
What decoupling capacitors are required for stable operation of the AT27C040-12TI?
The AT27C040-12TI requires two decoupling capacitors: a 0.1 µF high-frequency ceramic capacitor placed between VCC and GND as close as possible to pins 16 and 32, and a 4.7 µF bulk electrolytic capacitor located near the power entry point of the EPROM array. These values are specified in the Switching Considerations section to suppress transients caused by CE switching and stabilize VCC during rapid output transitions. Omitting either capacitor risks read corruption or premature device failure under dynamic load conditions.
How is the manufacturer and device identification code read from the AT27C040-12TI?
The AT27C040-12TI returns its identification codes by asserting VPP = 12.0 V, holding A1–A18 low, setting A9 = 12.0 V, and toggling A0: when A0 = VIL, the device outputs Manufacturer ID 0x1E on O7–O0; when A0 = VIH, it outputs Device ID 0x0B. This mode is entered only during programming voltage application and is used exclusively by industry-standard programmers to auto-detect part type and select correct algorithms - not accessible during normal read operation. The AT27C040-12TI does not expose ID codes via standard address/data bus reads.
AT27C040-12TI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-TFSOP (0.724", 18.40mm Width)
- Packaging:
- Tray
- 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:
- Surface Mount
- Supplier Device Package:
- 32-TSOP
AT27C040-12TI FAQ
1.How can I place an order for AT27C040-12TI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C040-12TI 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 AT27C040-12TI reliable?
The price and inventory of AT27C040-12TI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C040-12TI is usually 5 days.
3.What payment methods are accepted for AT27C040-12TI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C040-12TI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C040-12TI?
AT27C040-12TI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C040-12TI 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 AT27C040-12TI?
For technical support, including AT27C040-12TI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C040-12TI requirements.
6.How does Aetrix verify that AT27C040-12TI is sourced from the original manufacturer or authorized distributors?
All AT27C040-12TI 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 AT27C040-12TI meets industry standards.
7.What is the process for return or replacement of AT27C040-12TI?
All AT27C040-12TI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C040-12TI, 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 AT27C040-12TI part is unused and in its original packaging.
Return procedure for AT27C040-12TI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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