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Microchip Technology AT27C1024-55PC
- Part No.:
- AT27C1024-55PC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 40-DIP (0.600", 15.24mm)
- Datasheet:
-
AT27C1024-55PC.pdf
- Description:
- IC EPROM 1MBIT PARALLEL 40DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,799
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Product details
Overview
AT27C1024-55PC from Atmel is a 1-Mbit (64K × 16) one-time programmable EPROM in 40-lead PDIP package, featuring 55 ns read access time, 5V ±10% single-supply operation, and dual-line control (CE/OE) for bus contention avoidance. It delivers 30 mA active current at 5 MHz and supports industrial temperature range (–40°C to +85°C), enabling firmware storage in legacy 16-bit microprocessor systems without wait states.
For engineers reviewing the AT27C1024-55PC datasheet, AT27C1024-55PC pinout, AT27C1024-55PC application, or AT27C1024-55PC equivalent, key selection criteria include verified 55 ns tACC timing, PDIP-40 mechanical compatibility, OTP reliability for unmodified firmware images, and Rapid™ programming at 100 µs/word with VPP = 13.0 V.
Technical Context
The AT27C1024-55PC implements a CMOS-based OTP memory array organized as 64K words × 16 bits, with address decoding across A0–A15 and bidirectional 16-bit data outputs O0–O15. Its two-line enable architecture (CE and OE) enables precise output gating in high-speed bus environments, eliminating floating-bus conflicts during read cycles.
Programming relies on external VPP = 13.0 V applied to pin 1, with PGM strobe triggering 100 µs pulses under 6.5 V VCC bias; product identification uses A9 = 12.0 V and A0 toggling to select manufacturer (001Eh) or device code (00F1h) words. Standby current is specified at 100 µA max with CE high.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 1,048,576 bits (64K × 16) - supports full 16-bit data bus interface without multiplexing |
| Read Access Time (tACC) | 55 ns max - guarantees sub-18.2 MHz bus timing without WAIT insertion in 16-bit systems |
| Supply Voltage | 5V ±10% - compatible with standard TTL/CMOS logic rails; no auxiliary voltage required for read mode |
| Active Current (ICC) | 30 mA max at 5 MHz - enables thermal budget planning for dense EPROM arrays |
| Standby Current (ISB1) | 100 µA max (CMOS CE input) - supports low-power hold states in battery-backed or intermittent-read systems |
| Programming Voltage (VPP) | 13.0 V ±0.25 V - requires dedicated programming supply; not used during normal read operation |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade embedded controller and instrumentation applications |
Pinout & Package
AT27C1024-55PC is housed in a 40-lead plastic dual in-line package (PDIP), 0.600" wide, JEDEC MS-011 AC compliant. Both GND pins (pins 12 and 28) must be connected for stable operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A15 | Address Inputs | 16-bit address bus interface; fully decoded to select one of 64K words |
| O0–O15 | Data Outputs | True 16-bit parallel output bus; high-impedance when OE or CE inactive |
| CE | Chip Enable | Primary device select; places outputs in high-Z when high, enabling multi-device bus sharing |
| OE | Output Enable | Secondary gating signal; allows output control independent of CE for timing-critical bus arbitration |
| PGM | Program Strobe | Active-low pulse input that initiates 100 µs programming cycle when VPP = 13.0 V is present |
| VPP | Programming Supply | 13.0 V input required only during programming; must be applied after and removed before VCC |
| NC | No Connect | Pin 21 is unconnected; must remain floating or tied to ground per layout guidelines |
| GND (Pins 12, 28) | Ground Reference | Dual ground pins reduce ground bounce and improve noise immunity in high-speed read cycles |
| VCC | Power Supply | 5V ±10% main supply; powers all internal logic and output drivers during read and program modes |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/word typical programming time with up to 10 re-pulse attempts per word ensures production-line throughput and field-programming repeatability |
| Integrated Product Identification Code | Manufacturer ID (001Eh) and Device Code (00F1h) accessible via A9 = 12.0 V and A0 toggle - enables automated programmer validation and BOM traceability |
| Two-Line Output Control (CE/OE) | Independent chip and output enables eliminate bus contention in shared-memory systems and support burst-mode read sequencing |
| JEDEC-Standard PDIP Packaging | 40-lead 0.600" wide PDIP footprint ensures drop-in replacement for legacy 27C-series EPROMs including AT27C516 |
| ESD & Latchup Robustness | 2000V HBM ESD rating and 200 mA latchup immunity support handling in non-EPA environments and long-term system reliability |
Applications
| Industrial PLC Firmware Storage | Legacy 16-Bit Microprocessor Boot ROM |
|---|---|
|
Use Scenario: Storing fixed ladder logic and I/O mapping tables in programmable logic controllers operating in factory-floor environments with wide temperature swings. IC Role / Device Role / Timing Role: Non-volatile boot-time firmware repository accessed at power-up by Z8000 or 80C186 derivatives; provides deterministic 55 ns read latency. Use Value: Eliminates reliance on slow serial EEPROM or volatile RAM + battery backup; supports certified firmware immutability required for SIL-2 safety subsystems. |
Use Scenario: Hosting BIOS and peripheral initialization code in retro-computing or test equipment using 16-bit CPU architectures. IC Role / Device Role / Timing Role: Primary read-only instruction store mapped into upper memory space; enabled via CE/OE handshake synchronized to CPU clock domain. Use Value: Delivers zero-wait-state execution for critical startup routines, reducing boot time by >30% versus slower 70 ns EPROM alternatives. |
| Military Avionics Configuration Memory | Automated Test Equipment (ATE) Pattern ROM |
|
Use Scenario: Holding flight-control calibration constants and sensor compensation tables in airborne systems requiring radiation-tolerant, unalterable storage. IC Role / Device Role / Timing Role: OTP configuration memory accessed during pre-flight self-test; immune to accidental overwrite or bit-flip events. Use Value: Guarantees firmware integrity over 20+ year service life without refresh cycles or wear-leveling overhead. |
Use Scenario: Storing digital stimulus/response vectors for high-speed boundary-scan or functional test platforms. IC Role / Device Role / Timing Role: High-bandwidth pattern source feeding FPGA-based pattern generators; synchronized to 10–20 MHz test clocks. Use Value: 16-bit parallel output sustains >18 Mbps sustained data rate, exceeding serial flash bandwidth and avoiding FIFO bottlenecks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C1024-55DC | 55 ns tACC, same 64K×16 organization, but uses AMD's proprietary programming algorithm and lacks integrated ID code | Requires AMD-specific programmers; no electronic device identification for automated tooling | Select when existing AMD toolchain is deployed and ID code is unnecessary |
| MX27C1024-55PC | Same PDIP-40 package and pinout; 55 ns access, but standby current rated at 200 µA (vs. 100 µA for AT27C1024-55PC) | Higher ISB increases power in always-on systems; identical timing and voltage specs ensure functional substitution | Acceptable where standby power is non-critical and Atmel programming tools are unavailable |
Compared with AM27C1024-55DC and MX27C1024-55PC, the AT27C1024-55PC offers tighter standby current control and built-in ID code verification-critical for automated manufacturing and long-life industrial deployments where firmware authenticity and low quiescent power are design requirements.
Availability
AT27C1024-55PC is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy 16-bit microprocessor boot ROM, and military avionics configuration memory requiring stable component supply across extended product lifecycles.
Supply support for AT27C1024-55PC 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 semiconductor designer specializing in microcontrollers, non-volatile memory, and secure authentication ICs for industrial, automotive, and communications markets.
The AT27C1024 belongs to Atmel's OTP EPROM product line, engineered for high-reliability firmware storage in systems where code immutability, long-term data retention (>10 years), and deterministic timing are mandatory.
FAQ
What is the maximum operating frequency supported by the AT27C1024-55PC?
The AT27C1024-55PC does not operate at a clock frequency itself-it is an asynchronous memory device. Its 55 ns access time (tACC) supports reliable interfacing with microprocessors or FPGAs running up to approximately 18.2 MHz (1/55 ns) without wait states. System timing must account for CE and OE propagation delays, and actual maximum bus speed depends on board layout, loading, and controller timing margins. The AT27C1024-55PC datasheet specifies tCE and tOE delays of 55 ns and 25 ns respectively under standard load conditions.
Can the AT27C1024-55PC be reprogrammed after initial programming?
No, the AT27C1024-55PC is a one-time programmable (OTP) EPROM. Once programmed, its memory cells cannot be erased or rewritten electrically or optically. The silicon structure uses fusible links or floating-gate transistors permanently altered during the 13.0 V VPP programming cycle. Any attempt to reprogram will not restore previous data, and repeated programming pulses beyond specification may damage the device. The AT27C1024-55PC is intended for final firmware images requiring permanent, tamper-resistant storage.
What decoupling capacitors are required for stable operation of the AT27C1024-55PC?
Per the AT27C1024-55PC datasheet, a 0.1 µF ceramic capacitor must be placed between VCC and GND, mounted as close as possible to pins 20 and 28. For systems with multiple EPROMs or high-current switching, a 4.7 µF bulk electrolytic capacitor should also be connected between VCC and GND near the power entry point. These values suppress transient voltage excursions caused by CE switching and ensure stable VCC during rapid output transitions. Failure to implement both capacitors risks timing violations or data corruption during high-speed reads.
Does the AT27C1024-55PC support automatic product identification during programming?
Yes, the AT27C1024-55PC features an Integrated Product Identification Code accessible via A9 and A0. With all address lines low except A9 = 12.0 V, toggling A0 selects either the Manufacturer ID (001Eh) or Device Code (00F1h). This electronic signature allows industry-standard programmers to auto-detect the AT27C1024-55PC, verify correct algorithm selection, and prevent misprogramming. The ID code is factory-laser-trimmed and guaranteed functional across the full industrial temperature range.
Is the AT27C1024-55PC pin-compatible with the AT27C516 EPROM?
Yes-the AT27C1024-55PC is a direct upgrade from the AT27C516 (512K × 8) in PDIP-40 package. While the AT27C516 uses an 8-bit data bus (O0–O7) and 19 address lines (A0–A18), the AT27C1024-55PC repurposes pins 11–19 and 22–29 as O8–O15 and A13–A15, maintaining identical pin 1 (VPP), pin 20 (VCC), pin 12/28 (GND), and control signal locations. Board redesign is required to route the expanded 16-bit bus and additional address lines, but socket and footprint remain compatible.
AT27C1024-55PC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 40-DIP (0.600", 15.24mm)
- 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:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 40-PDIP
AT27C1024-55PC FAQ
1.How can I place an order for AT27C1024-55PC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C1024-55PC 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 AT27C1024-55PC reliable?
The price and inventory of AT27C1024-55PC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C1024-55PC is usually 5 days.
3.What payment methods are accepted for AT27C1024-55PC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C1024-55PC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C1024-55PC?
AT27C1024-55PC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C1024-55PC 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 AT27C1024-55PC?
For technical support, including AT27C1024-55PC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C1024-55PC requirements.
6.How does Aetrix verify that AT27C1024-55PC is sourced from the original manufacturer or authorized distributors?
All AT27C1024-55PC 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 AT27C1024-55PC meets industry standards.
7.What is the process for return or replacement of AT27C1024-55PC?
All AT27C1024-55PC units undergo pre-shipment inspection (PSI). If there is an issue with AT27C1024-55PC, 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 AT27C1024-55PC part is unused and in its original packaging.
Return procedure for AT27C1024-55PC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT27C1024-55PC Tags
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