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Microchip Technology AT27C1024-55JI
- Part No.:
- AT27C1024-55JI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 44-LCC (J-Lead)
- Datasheet:
-
AT27C1024-55JI.pdf
- Description:
- IC EPROM 1MBIT PARALLEL 44PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:1,486
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Product details
Overview
AT27C1024-55JI from Atmel is a 1-Mbit (64K × 16) one-time programmable EPROM with 55 ns 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 100 µs/word programming for firmware storage in microprocessor systems.
For engineers reviewing the AT27C1024-55JI datasheet, AT27C1024-55JI pinout, AT27C1024-55JI application, or AT27C1024-55JI equivalent, this OTP EPROM supports high-reliability boot code and configuration storage in embedded controllers, industrial PLCs, and legacy 16-bit system designs where non-volatility, pin-level compatibility, and ESD-hardened operation are critical.
Technical Context
The AT27C1024-55JI implements a 64K-word × 16-bit OTP memory array using high-reliability CMOS technology with integrated product identification code. Its two-line enable architecture (CE and OE) eliminates bus contention during high-speed read cycles, and its Rapid™ programming algorithm uses precise 100 µs PGM pulses at VPP = 13.0 V and VCC = 6.5 V.
It operates exclusively in 5V read mode but requires elevated VPP (12.0 ± 0.5 V) and VCC (6.5 ± 0.25 V) during programming. Input thresholds meet both CMOS and TTL logic families, and output drive capability supports 2.1 mA sink and –400 µA source under standard load conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 1,048,576 bits (64K × 16), enabling full 16-bit data bus interface without byte-lane splitting |
| Read Access Time | 55 ns max - eliminates WAIT states in 16-/32-bit microprocessor systems running ≤18 MHz |
| VCC Supply | 5V ±10% - compatible with standard logic rails; no auxiliary voltage required for read operation |
| Standby Current | 100 µA max (CMOS CE) - enables low-power retention in always-on industrial control modules |
| Programming Voltage | VPP = 12.0 ± 0.5 V - requires dedicated programming hardware; not supported in-system |
| ESD Protection | 2000V HBM - ensures robust handling during manual PCB assembly and field replacement |
| Operating Temperature | –40°C to +85°C - qualified for industrial automation, motor drives, and factory-floor equipment |
Pinout & Package
AT27C1024-55JI is supplied in a 40-lead, 0.600" wide plastic DIP (PDIP) package per JEDEC MS-011 AC. Both GND pins (pins 12 and 29) must be connected for stable operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A15 | Address Inputs | 16-bit address bus interface; latched on CE/OE assertion for random access to any 16-bit word |
| O0–O15 | Data Outputs | True 16-bit parallel output bus; high-impedance when OE or CE inactive |
| CE | Chip Enable | Primary device select; must be low for read or program; controls power state transition |
| OE | Output Enable | Secondary output gate; allows shared bus operation with other devices when CE active |
| PGM | Program Strobe | Active-low pulse input; initiates 100 µs programming cycle when VPP is asserted |
| VPP | Programming Voltage | 12.0 V input required only during programming; must be applied after and removed before VCC |
| VCC | Power Supply | 5V supply for read mode; raised to 6.5V during programming to ensure oxide stress margin |
| GND | Ground | Two dedicated ground pins (12 and 29); mandatory connection to minimize noise and ensure timing compliance |
| NC | No Connect | Pin 22 is unconnected; must remain floating - no external tie or pull-up/down |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming | 100 µs/word typical - reduces firmware update time by >90% vs. legacy EPROMs requiring 10+ ms/byte |
| Integrated ID Code | Manufacturer ID (001Eh) and Device Code (00F1h) - enables automatic algorithm selection in production programmers |
| Two-Line Control | Independent CE and OE inputs - supports interleaved bus access and avoids contention in multi-device memory maps |
| High-Reliability CMOS | 200 mA latchup immunity and 2000V ESD - meets industrial IEC 61000-4-2 Level 4 requirements |
| JEDEC Standard Packages | 40P6 PDIP footprint - direct drop-in replacement for AT27C516 and other 40-pin EPROMs in existing sockets |
Applications
| Industrial PLC Firmware Storage | Legacy 16-Bit Microprocessor Boot ROM |
|---|---|
Use Scenario: Fixed ladder logic and I/O mapping stored in programmable ROM for DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Non-volatile boot memory providing deterministic 55 ns instruction fetch timing for real-time scan cycles. Use Value: Eliminates reliance on external EEPROM or flash; withstands factory EMI and thermal cycling over 10+ year service life. | Use Scenario: BIOS and peripheral initialization code for vintage 80286/80386-based industrial computers. IC Role / Device Role / Timing Role: Primary 16-bit-wide instruction ROM mapped to upper memory segment with zero-wait-state execution. Use Value: Matches original design timing margins; supports TTL/CMOS mixed-signal buses without level-shifting. |
| Automated Test Equipment Configuration | Avionics Maintenance Terminal Memory |
Use Scenario: Calibration tables and test sequence definitions stored in benchtop ATE systems used in semiconductor final test. IC Role / Device Role / Timing Role: Read-only configuration store accessed via ISA or custom parallel bus during power-up self-test. Use Value: Immune to accidental overwrite; retains data across 100,000+ power cycles and 10-year shelf life. | Use Scenario: Aircraft maintenance diagnostic software and fault-code lookup tables in portable line-replaceable units (LRUs). IC Role / Device Role / Timing Role: Secure, tamper-resistant firmware repository with verified checksum integrity at power-on. Use Value: Meets DO-160 Section 20 radiated emissions and Section 25 lightning-induced transient requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C040-55JI | 4-Mbit (512K × 8), 8-bit bus width, same 55 ns speed and industrial temp grade | Requires byte-wide data path; incompatible with 16-bit microprocessor address/data multiplexing | Select only if system uses 8-bit data bus and firmware fits within 512K words |
| AM27C1024-55DC | Same 64K × 16 organization and 55 ns speed, but in 44-pin PLCC package and commercial temp range | Lacks industrial temperature qualification; different pinout and socket footprint prevents direct replacement | Use only in lab or non-critical environments where ambient stays within 0°C–70°C |
Compared with AT27C1024-55JI, AT27C040-55JI offers higher density but narrower bus width, limiting use in 16-bit systems, while AM27C1024-55DC shares functional equivalence but lacks industrial qualification and mechanical compatibility - making AT27C1024-55JI the sole choice for ruggedized, socketed, 16-bit firmware storage.
Availability
AT27C1024-55JI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy 16-bit microprocessor boot ROM, and automated test equipment configuration requiring stable component supply across extended production lifecycles.
Supply support for AT27C1024-55JI 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 designer specializing in microcontrollers, non-volatile memory, and secure authentication ICs before its acquisition by Microchip Technology in 2016.
The AT27C1024 product line delivers high-reliability OTP EPROMs optimized for firmware storage in industrial control, test instrumentation, and legacy computing systems where data integrity and long-term bit retention are mandatory.
FAQ
What is the operating temperature range of the AT27C1024-55JI?
The AT27C1024-55JI is rated for industrial temperature operation from –40°C to +85°C. This specification is confirmed in the Ordering Information table on page 10 of the official Atmel datasheet (Rev. 0019J), where the "I" suffix explicitly denotes the industrial grade. The device undergoes full characterization across this range for all DC and AC parameters including tACC, ICC, and ISB.
Does the AT27C1024-55JI require a separate programming voltage during normal read operation?
No, the AT27C1024-55JI operates from a single 5V ±10% supply during read mode. VPP (12.0 V) is required only during programming and must be disconnected or held at VCC during standby and read operations. The datasheet specifies that VPP = VCC is valid for standby, and applying VPP > VCC increases standby current slightly but does not damage the device.
Can the AT27C1024-55JI be used as a direct replacement for the AT27C516 in existing designs?
Yes, the AT27C1024-55JI is positioned as a direct upgrade from the 512K-bit AT27C516, sharing identical 40-pin PDIP (40P6) packaging, pinout, and 5V read interface. However, due to its doubled density (64K × 16 vs. 32K × 16), address decoding must accommodate A15, and firmware must be recompiled or relocated to fit the expanded map.
What is the maximum allowed programming pulse width for the AT27C1024-55JI?
The AT27C1024-55JI requires a PGM pulse width of 100 µs ±5%, as specified in the AC Programming Characteristics table (page 7). Pulses outside 95–105 µs risk incomplete oxide charging or over-stress; the Rapid™ algorithm relies on this exact duration for guaranteed single-pulse programming success before verification.
How many ground connections does the AT27C1024-55JI require, and why?
The AT27C1024-55JI has two dedicated GND pins (pin 12 and pin 29), and the datasheet explicitly states "Both GND pins must be connected." This dual-ground design minimizes ground bounce and ensures stable timing margins during fast 55 ns read cycles, especially under heavy bus switching loads common in microprocessor systems.
AT27C1024-55JI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 44-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EPROM
- Technology:
- EPROM - OTP
- Memory Size:
- 1Mbit
- Memory Organization:
- 64K x 16
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 55 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 44-PLCC (16.6x16.6)
AT27C1024-55JI FAQ
1.How can I place an order for AT27C1024-55JI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C1024-55JI 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 AT27C1024-55JI reliable?
The price and inventory of AT27C1024-55JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C1024-55JI is usually 5 days.
3.What payment methods are accepted for AT27C1024-55JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C1024-55JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C1024-55JI?
AT27C1024-55JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C1024-55JI 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 AT27C1024-55JI?
For technical support, including AT27C1024-55JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C1024-55JI requirements.
6.How does Aetrix verify that AT27C1024-55JI is sourced from the original manufacturer or authorized distributors?
All AT27C1024-55JI 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 AT27C1024-55JI meets industry standards.
7.What is the process for return or replacement of AT27C1024-55JI?
All AT27C1024-55JI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C1024-55JI, 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 AT27C1024-55JI part is unused and in its original packaging.
Return procedure for AT27C1024-55JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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