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Microchip Technology AT27C512R-45RI
- Part No.:
- AT27C512R-45RI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.342", 8.69mm Width)
- Datasheet:
-
AT27C512R-45RI.pdf
- Description:
- IC EPROM 512KBIT PARALLEL 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,319
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Product details
Overview
AT27C512R-45RI from Atmel is a 512 Kbit (64K × 8) one-time programmable EPROM with 45 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™ programming at 100 µs/byte - used for firmware storage in microprocessor-based embedded controllers and legacy industrial PLCs.
For engineers reviewing the AT27C512R-45RI datasheet, AT27C512R-45RI pinout, AT27C512R-45RI application, or AT27C512R-45RI equivalent, key selection criteria include verified 45 ns tACC timing, industrial-grade standby current (≤100 µA), JEDEC-standard 28-lead SOIC package compatibility, and OTP reliability for unchangeable boot code storage.
Technical Context
The AT27C512R-45RI implements a standard OTP EPROM architecture with address decoding for A0–A15, 8-bit bidirectional data outputs (O0–O7), and two active-low control lines: CE (Chip Enable) and OE/VPP (Output Enable / Programming Voltage). Its block diagram confirms no internal latches or state machines - pure combinational read path from address to output.
It supports three distinct operational modes: Read (CE=OE=VIL), Standby (CE=VIH), and Rapid Programming (CE=VIL, OE/VPP=13.0V). The integrated product identification code uses A9 at 12.0V and A0 toggling to return manufacturer (0x1E) and device (0x0D) bytes - enabling automated programmer recognition without external configuration.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 524,288 bits (64K × 8) - stores full firmware images for 8-bit microcontrollers like 8051 or Z80. |
| Read Access Time (tACC) | 45 ns max - enables direct interface with 20 MHz+ CPU buses without wait states. |
| Supply Voltage | 5V ±10% - compatible with legacy 5V logic systems; no auxiliary voltage rails required. |
| Standby Current (ISB1) | 100 µA max - supports low-power hold mode in battery-backed industrial controllers. |
| Active Current (ICC) | 20 mA max at 5 MHz - limits thermal load in dense PCB layouts with multiple EPROMs. |
| ESD Protection | 2,000V HBM - meets industrial handling requirements per ANSI/ESDA JS-001. |
| Programming Speed | 100 µs/byte typical - reduces production programming cycle time by >5× vs. legacy EPROMs. |
Pinout & Package
AT27C512R-45RI is supplied in a 28-lead SOIC (package code "R", JEDEC MS-012AB), 0.330" wide body, with 1.27 mm pitch. Pin 1 index mark located at top-left corner; pin 14 = GND, pin 28 = VCC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A15 | Address Inputs | 16-bit address bus interface; decoded internally to select one of 64K bytes. |
| O0–O7 | Data Outputs | CMOS/TTL-compatible 8-bit data bus; high-impedance when CE or OE inactive. |
| CE | Chip Enable | Active-low global enable; must be stable before address setup to meet tAS timing. |
| OE/VPP | Output Enable / Programming Voltage | Read mode: active-low output gate; Program mode: accepts 13.0V for byte programming. |
| GND | Ground Reference | Pins 14 (SOIC) - primary return path for VCC and I/O currents; requires local 0.1 µF ceramic decoupling. |
| VCC | Power Supply | Pin 28 (SOIC) - supplies core logic and output drivers; must ramp with OE/VPP per datasheet sequencing. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical write time with auto-verify loop - eliminates manual verification steps in production programming. |
| Integrated Product ID Code | Manufacturer (0x1E) and device (0x0D) bytes readable via A9=12V/A0 toggle - enables plug-and-play programmer compatibility. |
| Two-Line Control Architecture | Independent CE and OE inputs - prevents bus contention in multi-device memory maps and simplifies address decoder design. |
| Industrial Temperature Range | -40°C to +85°C operation - qualified for use in motor drives, factory automation I/O modules, and outdoor telecom equipment. |
| JEDEC-Standard SOIC Package | 28-lead, 0.330" wide, 1.27 mm pitch - ensures drop-in replacement for legacy 27C512 designs and compatibility with standard reflow profiles. |
Applications
| Industrial PLC Firmware Storage | Legacy Microcontroller Boot ROM |
|---|---|
Use Scenario: Storing fixed ladder logic execution engine and I/O mapping tables in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Non-volatile boot memory providing deterministic 45 ns instruction fetch latency to 80C31-based control CPUs. Use Value: Eliminates reliance on volatile RAM + battery backup; withstands 2,000V ESD events common in factory floor wiring environments. |
Use Scenario: Holding immutable startup code and hardware initialization routines for Z80 or 68000-based test equipment mainframes. IC Role / Device Role / Timing Role: Primary read-only program memory mapped into CPU address space with zero-wait-state timing. Use Value: Guarantees consistent power-on behavior across decades of field deployment; no firmware corruption risk from power glitches. |
| Automotive Diagnostic Tool Memory | Medical Device Configuration ROM |
Use Scenario: Storing OBD-II protocol translation tables and vehicle-specific calibration constants in handheld diagnostic scanners. IC Role / Device Role / Timing Role: Static lookup table memory accessed via 8-bit parallel bus during CAN message parsing. Use Value: Qualified for -40°C to +85°C operation - survives under-hood temperature cycling in service bay environments. |
Use Scenario: Holding FDA-mandated safety-critical device configuration parameters (e.g., infusion pump flow rates, alarm thresholds) in Class II medical electronics. IC Role / Device Role / Timing Role: Tamper-proof OTP storage preventing unauthorized runtime modification of life-critical settings. Use Value: One-time programmability ensures configuration integrity; 200 mA latchup immunity protects against ESD-induced system resets. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C512-45DC | 45 ns tACC, 28-pin PDIP only; no SOIC option; higher ISB (200 µA); lacks integrated ID code. | Requires PCB layout change for SOIC footprint; unsuitable for automated ID-based programming workflows. | Select only if PDIP is mandated and ID code not needed. |
| MX27C512-45PC | 45 ns tACC, 28-pin PDIP; 5V ±5% supply tolerance; no VPP pin - uses internal charge pump for programming. | Cannot replace AT27C512R-45RI in SOIC-based designs; incompatible programming voltage scheme (no 13V OE/VPP). | Choose only for new PDIP-only designs where simplified programming voltage is prioritized over footprint compatibility. |
Compared with AM27C512-45DC and MX27C512-45PC, the AT27C512R-45RI uniquely combines SOIC packaging, integrated ID code, and 100 µA industrial standby current - making it the only drop-in replacement for existing AT27C512R-based industrial control boards requiring minimal redesign.
Availability
AT27C512R-45RI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy microcontroller boot ROM, and automotive diagnostic tool memory requiring stable component supply across extended product lifecycles.
Supply support for AT27C512R-45RI 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 company specializing in microcontrollers, non-volatile memory, and secure authentication ICs for industrial and automotive markets.
The AT27C512R product line was designed specifically for cost-sensitive, high-reliability OTP firmware storage in 5V microprocessor systems - emphasizing fast read access, low standby power, and JEDEC-standard packaging for long-term design stability.
FAQ
What is the maximum operating temperature range for the AT27C512R-45RI?
The AT27C512R-45RI is rated for industrial temperature operation from -40°C to +85°C. This range is confirmed in the Ordering Information table on page 9 of the datasheet, where the suffix "I" denotes industrial grade. It is not rated for automotive (-40°C to +125°C) or extended commercial ranges.
Does the AT27C512R-45RI require a 12V programming voltage?
Yes - the AT27C512R-45RI requires 13.0V ±0.25V on the OE/VPP pin during programming, as specified in the DC Programming Characteristics table (page 6). This voltage is mandatory for the Rapid™ algorithm; applying only 5V to OE/VPP will not program the device.
Can the AT27C512R-45RI be used as a direct replacement for the older AT27C512-45PI?
No - the AT27C512R-45RI is not a direct replacement for AT27C512-45PI. While both are 45 ns OTP EPROMs, the "R" suffix indicates the revised version with integrated product ID code and updated Rapid™ programming algorithm. The original AT27C512 lacks ID code functionality and uses a different programming sequence.
What decoupling capacitance is required for stable operation of the AT27C512R-45RI?
The AT27C512R-45RI requires a minimum 0.1 µF high-frequency ceramic capacitor between VCC and GND, placed as close as possible to pins 28 and 14. For arrays with multiple devices, a 4.7 µF bulk electrolytic capacitor is also recommended near the power entry point, per System Considerations section (page 2).
Is the AT27C512R-45RI pin-compatible with the 28-pin SOIC version of the AT27C256B?
No - the AT27C512R-45RI is not pin-compatible with AT27C256B. Although both use 28-pin SOIC packages, the AT27C256B has only 15 address lines (A0–A14) and lacks the A15 pin. The AT27C512R-45RI uses A0–A15 and places A15 on pin 1, while AT27C256B uses pin 1 for VCC - making direct substitution electrically invalid.
AT27C512R-45RI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-SOIC (0.342", 8.69mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EPROM
- Technology:
- EPROM - OTP
- Memory Size:
- 512Kbit
- Memory Organization:
- 64K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 45 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOIC
AT27C512R-45RI FAQ
1.How can I place an order for AT27C512R-45RI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C512R-45RI 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 AT27C512R-45RI reliable?
The price and inventory of AT27C512R-45RI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C512R-45RI is usually 5 days.
3.What payment methods are accepted for AT27C512R-45RI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C512R-45RI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C512R-45RI?
AT27C512R-45RI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C512R-45RI 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 AT27C512R-45RI?
For technical support, including AT27C512R-45RI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C512R-45RI requirements.
6.How does Aetrix verify that AT27C512R-45RI is sourced from the original manufacturer or authorized distributors?
All AT27C512R-45RI 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 AT27C512R-45RI meets industry standards.
7.What is the process for return or replacement of AT27C512R-45RI?
All AT27C512R-45RI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C512R-45RI, 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 AT27C512R-45RI part is unused and in its original packaging.
Return procedure for AT27C512R-45RI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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