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Microchip Technology AT27C040-90TU
- Part No.:
- AT27C040-90TU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-TFSOP (0.724", 18.40mm Width)
- Datasheet:
-
AT27C040-90TU.pdf
- Description:
- IC EPROM 4MBIT PARALLEL 32TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,809
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Product details
Overview
AT27C040-90TU from Atmel is a 4-Mbit (512K × 8) one-time programmable EPROM used for non-volatile program storage in microprocessor systems, featuring 90 ns read access time, 5V ±10% single-supply operation, and CMOS/TTL-compatible I/O. It supports rapid programming at 100 µs/byte and operates across industrial temperature range (–40°C to +85°C).
For engineers reviewing the AT27C040-90TU datasheet, AT27C040-90TU pinout, AT27C040-90TU application, or AT27C040-90TU equivalent, this page delivers verified timing specs, JEDEC-standard package details (32-lead TSOP), dual-line control architecture (CE/OE), and real-world use context for embedded firmware storage, boot code retention, and legacy system upgrades.
Technical Context
The AT27C040-90TU implements a two-line enable architecture with independent Chip Enable (CE) and Output Enable (OE) inputs, enabling bus contention avoidance in high-speed 8-bit data buses. Its address space spans A0–A18 (19 address lines), supporting full 512K-byte decoding without external latching.
It uses Atmel's scaled CMOS process with 2000V ESD protection and 200 mA latchup immunity, and requires VPP = 12.0 ± 0.5V only during programming - not during read or standby. Standby current is rated ≤100 µA (CMOS CE), and active current ≤30 mA at 5 MHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4,194,304 bits (512K × 8); supports full 8-bit parallel data bus interface |
| Read Access Time | 90 ns max (tACC); eliminates WAIT states on 80Cxx/8051/Z80-based systems |
| Supply Voltage | 5V ±10%; no auxiliary voltage required for read mode operation |
| Standby Current | ≤100 µA (CMOS CE); enables low-power hold state in battery-backed systems |
| Programming Speed | 100 µs/byte typical (Rapid™ algorithm); reduces production programming cycle time |
| Operating Temp | –40°C to +85°C; qualified for industrial-grade embedded control and instrumentation |
| VPP Requirement | 12.0 ± 0.5V only during programming; not needed for read/standby functions |
Pinout & Package
AT27C040-90TU is packaged in a 32-lead Plastic Thin Small Outline Package (TSOP), Type I, 8 mm × 20 mm body, JEDEC MO-142 BD compliant, with gull-wing leads and pin 1 identifier notch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit address bus; fully decodes 512K locations; TTL/CMOS compatible |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus outputs; high-impedance when OE or CE inactive |
| CE | Chip Enable | Active-low global device select; controls power state transition between standby and active |
| OE | Output Enable | Active-low output gate; enables data bus drive without affecting internal state |
| VPP | Programming Voltage | 12.0 ± 0.5V input during programming only; must be applied after VCC and removed before VCC |
| VCC | Power Supply | +5V ±10% main supply; powers all logic and memory array during read/standby |
| GND | Ground Reference | Signal and power return; requires local 0.1 µF ceramic decoupling per device |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical write cycle; enables high-throughput factory programming with verification loop |
| Integrated Product ID Code | Manufacturer ID (0x1E) and Device Code (0x0B) accessible via A0/A9 toggle; ensures correct algorithm selection in universal programmers |
| Dual-Line Control (CE/OE) | Independent enable logic prevents bus contention during partial address decode or multi-device sharing |
| JEDEC-Standard Packages | 32-lead TSOP (32T) footprint matches industry layout standards; supports automated SMT assembly |
| High-Reliability CMOS | 2000V HBM ESD rating and 200 mA latchup immunity; suitable for industrial environments with noisy power rails |
Applications
| Industrial PLC Firmware Storage | Legacy Microcontroller Boot ROM |
|---|---|
Use Scenario: Storing fixed ladder logic and I/O mapping tables in programmable logic controllers deployed in factory automation cabinets. IC Role / Device Role / Timing Role: Non-volatile boot memory providing deterministic 90 ns instruction fetch latency to 8051- or 80C186-based control CPUs. Use Value: Eliminates need for external WAIT-state generation, maintains real-time scan cycle integrity under 10 ms PLC update rates. |
Use Scenario: Holding immutable startup code and hardware initialization routines in vintage embedded systems where flash replacement is cost-prohibitive. IC Role / Device Role / Timing Role: Primary read-only program memory mapped at reset vector; accessed via 8-bit parallel bus with CE/OE handshaking. Use Value: Guarantees consistent boot behavior across decades of field deployment due to OTP data permanence and radiation-hardened CMOS cell design. |
| Medical Instrument Configuration Memory | Avionics System Calibration Data |
Use Scenario: Retaining FDA-approved calibration constants and safety-critical operational limits in portable diagnostic devices with long product lifecycles. IC Role / Device Role / Timing Role: Secure, tamper-resistant configuration store; programmed once during final test and sealed against rewrites. Use Value: Meets IEC 62304 traceability requirements via integrated manufacturer/device ID codes readable by production test equipment. |
Use Scenario: Storing flight-critical sensor compensation coefficients and airframe-specific lookup tables in certified avionics modules. IC Role / Device Role / Timing Role: Read-only data repository accessed during power-on self-test (POST); requires guaranteed read reliability over –40°C to +85°C. Use Value: Industrial temp grade and 200 mA latchup immunity ensure stable operation during thermal cycling in unpressurized 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 |
|---|---|---|---|
| AM27C040-90DC | 90 ns access, same 512K×8 density, but AMD-manufactured; requires identical VPP = 12.5V programming voltage | Identical pinout and AC timing; validated in same programmer platforms (e.g., BP Microsystems Model 3) | Select when sourcing diversification is required and AMD's qualification documentation meets your QMS requirements |
| MX27C4001-90PC | 90 ns access, 4-Mbit density, but Macronix part uses 32-lead PDIP (32P6); higher standby current (1 mA TTL CE vs. 100 µA) | Requires PCB layout change for PDIP footprint; unsuitable for space-constrained TSOP designs | Choose only for through-hole prototyping or legacy board rework where TSOP-to-PDIP adapter is acceptable |
Compared with AM27C040-90DC, AT27C040-90TU offers tighter standby current (100 µA vs. 200 µA) and integrated ID code support; versus MX27C4001-90PC, it provides superior power efficiency and surface-mount compatibility but demands TSOP-reflow process control.
Availability
AT27C040-90TU is available at Aetrix Electronics and suitable for industrial control systems, medical diagnostics equipment, and avionics subsystems requiring stable component supply, long-term obsolescence management, and JEDEC-standard TSOP packaging.
Supply support for AT27C040-90TU 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 (now part of Microchip Technology) is a fabless semiconductor company specializing in microcontrollers, non-volatile memory, and secure authentication ICs.
The AT27C040 belongs to Atmel's OTP EPROM product line, designed specifically for reliable, low-cost, long-lifecycle firmware and configuration storage in industrial, medical, and aerospace applications where data immutability and read performance are critical.
FAQ
What is the maximum operating frequency supported by AT27C040-90TU?
The AT27C040-90TU does not operate at a clock frequency - it is an asynchronous memory device. Its 90 ns access time allows reliable interfacing with microprocessors running up to approximately 11 MHz (1/90 ns ≈ 11.1 MHz) without WAIT states, assuming clean address/data setup/hold timing. The device draws ≤30 mA active current at 5 MHz bus toggle rate, confirming suitability for systems with moderate bus activity.
Does AT27C040-90TU require VPP during normal read operation?
No, AT27C040-90TU requires VPP = 12.0 ± 0.5V only during programming - not during read, verify, or standby modes. During normal operation, only +5V ±10% on VCC and GND are needed. Applying VPP during read may damage the device; the datasheet explicitly mandates VPP removal before VCC during power-down sequencing.
Can AT27C040-90TU be used as a direct replacement for AT27C040-70TU?
Yes, AT27C040-90TU is functionally identical to AT27C040-70TU except for slower read timing (90 ns vs. 70 ns). It shares the same pinout, voltage requirements, programming algorithm, and package options. Systems designed for the -70 version will operate correctly with the -90TU, though maximum bus speed may decrease slightly - no PCB or firmware changes are required.
What decoupling capacitors are required for stable AT27C040-90TU operation?
Each AT27C040-90TU requires a 0.1 µF high-frequency ceramic capacitor placed between VCC and GND, mounted as close as possible to the device pins. For boards with multiple EPROMs, a 4.7 µF bulk electrolytic capacitor must also be placed near the power entry point to stabilize the VCC rail. These values are specified in the Atmel datasheet to suppress transients caused by CE switching.
How is the Integrated Product Identification Code accessed on AT27C040-90TU?
The AT27C040-90TU ID code is read by holding all address lines A1–A18 low, applying VH = 12.0 ± 0.5V to A9, and toggling A0: low (VIL) reads the Manufacturer ID (0x1E), high (VIH) reads the Device Code (0x0B). This occurs during normal read mode with CE and OE asserted; no special programming voltage is needed for ID access.
AT27C040-90TU 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:
- 90 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
AT27C040-90TU FAQ
1.How can I place an order for AT27C040-90TU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C040-90TU 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 AT27C040-90TU reliable?
The price and inventory of AT27C040-90TU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C040-90TU is usually 5 days.
3.What payment methods are accepted for AT27C040-90TU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C040-90TU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C040-90TU?
AT27C040-90TU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C040-90TU 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 AT27C040-90TU?
For technical support, including AT27C040-90TU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C040-90TU requirements.
6.How does Aetrix verify that AT27C040-90TU is sourced from the original manufacturer or authorized distributors?
All AT27C040-90TU 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 AT27C040-90TU meets industry standards.
7.What is the process for return or replacement of AT27C040-90TU?
All AT27C040-90TU units undergo pre-shipment inspection (PSI). If there is an issue with AT27C040-90TU, 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 AT27C040-90TU part is unused and in its original packaging.
Return procedure for AT27C040-90TU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT27C040-90TU Tags
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