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Microchip Technology AT27C512R-45RC
- Part No.:
- AT27C512R-45RC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.342", 8.69mm Width)
- Datasheet:
-
AT27C512R-45RC.pdf
- Description:
- IC EPROM 512KBIT PARALLEL 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,382
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Product details
Overview
AT27C512R-45RC from Microchip Technology (formerly Atmel) is a 64K × 8-bit one-time programmable EPROM used for firmware storage in microprocessor systems. It delivers 45 ns read access time, operates on a single 5V ±10% supply, and supports commercial temperature range (0°C to 70°C) in 28-lead SOIC package. Its dual-line control (CE/OE) prevents bus contention in embedded boot memory applications.
For engineers reviewing the AT27C512R-45RC datasheet, AT27C512R-45RC pinout, AT27C512R-45RC application, or AT27C512R-45RC equivalent, key selection criteria include verified 45 ns tACC timing, 100 µA max standby current, JEDEC-compliant SOIC-28 footprint, and Rapid™ programming compatibility at 100 µs/byte.
Technical Context
The AT27C512R-45RC implements a CMOS OTP EPROM architecture with address decoding for A0–A15 and 8-bit bidirectional data I/O (O0–O7). Its two-control-line interface (CE and OE/VPP) enables flexible bus arbitration and eliminates WAIT states in high-speed 8/16-bit microprocessor systems.
It uses Atmel's scaled CMOS process for low-power operation: active current ≤20 mA at 5 MHz and standby current ≤100 µA. Programming requires VCC = 6.5 V and OE/VPP = 13.0 V, with integrated product identification (Manufacturer ID = 0x1E, Device ID = 0x0D) for automated programmer recognition.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 524,288 bits (64K × 8), sufficient for full BIOS or bootloader images in legacy embedded systems |
| Read Access Time | 45 ns maximum - enables direct connection to 22 MHz Z80 or 12.5 MHz 8086 without wait-state insertion |
| Supply Voltage | 5V ±10% - compatible with standard TTL/CMOS logic rails and eliminates need for auxiliary voltage regulators |
| Standby Current | ≤100 µA - supports low-power hold modes in battery-backed or energy-constrained industrial controllers |
| Active Current | ≤20 mA at 5 MHz - reduces thermal load and simplifies power delivery in dense PCB layouts |
| ESD Protection | 2,000V HBM - meets industrial handling requirements without additional protection circuitry |
| Latchup Immunity | 200 mA - withstands transient overcurrent events during hot-plug or power sequencing |
Pinout & Package
AT27C512R-45RC is packaged in a 28-lead, 0.330" wide plastic gull-wing small outline (SOIC), per JEDEC MS-012 standard. Pin 1 is marked by index notch or dot; leads are gull-wing profile with 0.050" pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A15 | Address Inputs | 16-bit address bus interface; fully decoded to select one of 64K bytes |
| O0–O7 | Data Outputs | 8-bit unidirectional data bus outputs during read mode; high-impedance when disabled |
| CE | Chip Enable | Primary device select; must be low for read or program operations; controls power state transition |
| OE/VPP | Output Enable / Programming Voltage | Low during read to enable outputs; raised to 13.0 V during programming to activate internal fuse-link circuitry |
| VCC | Power Supply | +5V ±10% supply input; must be applied before/with OE/VPP and removed after/with OE/VPP |
| 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 - reduces production programming time by >5× vs. legacy EPROMs, enabling high-throughput firmware loading |
| Integrated Product ID Code | Manufacturer ID = 0x1E, Device ID = 0x0D - allows automatic algorithm selection and voltage validation in universal programmers |
| Two-Line Control Architecture | Separate CE and OE/VPP pins - eliminates bus contention in multi-device memory maps and supports partial-memory-enable schemes |
| JEDEC-Standard SOIC Package | 28-lead, 0.330" wide SOIC (package code "R") - ensures drop-in replacement capability and compatibility with standard SMT reflow profiles |
| High-Reliability CMOS Process | 2,000V ESD + 200 mA latchup immunity - sustains robust operation in factory automation and test equipment environments |
Applications
| Industrial PLC Firmware Storage | Legacy PC BIOS Memory |
|---|---|
Use Scenario: Storing fixed ladder logic and I/O configuration in programmable logic controllers deployed in factory-floor environments. IC Role / Device Role / Timing Role: Non-volatile boot memory providing deterministic 45 ns read access to initialization code during cold start. Use Value: Eliminates reliance on slower EEPROM or flash, ensuring sub-100 ms system boot and eliminating firmware corruption risk from power loss during write cycles. | Use Scenario: Holding POST routines and hardware initialization code in desktop motherboards using Intel 80286/80386 chipsets. IC Role / Device Role / Timing Role: Primary ROM device mapped to 0xF0000–0xFFFFF address space; accessed via 8-bit data bus with CE/OE-controlled gating. Use Value: Guarantees 45 ns tACC compliance with 80386's 12.5 MHz bus timing, removing wait-state logic and reducing board complexity. |
| Medical Instrument Bootloader | Avionics Configuration Memory |
Use Scenario: Storing immutable bootloader and calibration constants in Class II medical devices requiring regulatory traceability and no field updates. IC Role / Device Role / Timing Role: One-time programmable firmware vault; read-only operation ensures runtime integrity and audit compliance. Use Value: Meets IEC 62304 software safety requirements by preventing accidental or malicious modification post-manufacture. | Use Scenario: Holding aircraft-specific configuration tables (e.g., sensor scaling, fault thresholds) in flight control units certified to DO-254. IC Role / Device Role / Timing Role: Radiation-tolerant (via process hardening) non-volatile memory storing critical lookup data accessed during pre-flight self-test. Use Value: Provides guaranteed data retention >20 years and immunity to single-event upsets without refresh overhead. |
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; 1 mA TTL-mode standby current vs. 100 µA CMOS standby | Requires PCB layout change for SOIC-to-PDIP conversion; higher standby draw limits use in battery-backed systems | Select only if legacy PDIP socketing is mandatory and power budget allows ≥10× higher standby current |
| MX27C512-45PC | 45 ns tACC, 28-pin PDIP; 200 µA max standby; lacks integrated product ID code and Rapid™ programming support | Needs manual algorithm selection in programmers; no automated device verification during programming | Choose when cost is primary constraint and programming throughput or auto-identification is not required |
Compared with AM27C512-45DC and MX27C512-45PC, the AT27C512R-45RC offers lower standby power, SOIC packaging for space-constrained designs, and built-in ID code for reliable programming - making it optimal for new industrial controller and medical device designs where layout efficiency and manufacturing repeatability matter.
Availability
AT27C512R-45RC is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy PC BIOS replacement, and medical instrument bootloader applications requiring stable component supply across extended product lifecycles.
Supply support for AT27C512R-45RC 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
Microchip Technology acquired Atmel in 2016 and maintains full technical and supply chain support for legacy Atmel memory products including the AT27C512R series.
The AT27C512R product line was designed for high-reliability, non-updatable firmware storage in industrial, medical, and aerospace systems where data integrity, long-term retention, and programming repeatability are critical.
FAQ
What is the maximum operating temperature range for the AT27C512R-45RC?
The AT27C512R-45RC is rated for commercial temperature operation from 0°C to 70°C. This range is confirmed in the Ordering Information table (page 9), where "RC" suffix denotes the SOIC package with commercial-grade temperature specification. It is not rated for industrial (−40°C to +85°C) or automotive (−40°C to +125°C) ranges - those require suffixes "RI", "RA", etc. The AT27C512R-45RC must be used within its specified ambient envelope to guarantee 45 ns access time and 100 µA standby current.
Does the AT27C512R-45RC support in-system programming?
No, the AT27C512R-45RC does not support in-system programming. It is a one-time programmable (OTP) EPROM that requires external UV-erasable or dedicated EPROM programmers applying 13.0 V to the OE/VPP pin. Programming must occur off-board under controlled voltage and timing conditions (e.g., 100 µs CE pulse width, VCC = 6.5 V). The device lacks JTAG, SPI, or other serial interfaces needed for in-circuit reprogramming - its architecture assumes final firmware image is written once during manufacturing.
What decoupling capacitance is required for stable operation of the AT27C512R-45RC?
The AT27C512R-45RC requires a minimum 0.1 µF high-frequency ceramic capacitor between VCC and GND, placed as close as possible to the device's pins. Per the System Considerations section (page 2), this capacitor mitigates transient voltage excursions during CE-driven active/standby transitions. For boards with multiple AT27C512R-45RC devices, a bulk 4.7 µF electrolytic capacitor should also be placed near the array's power entry point. These values are mandatory for compliance with Absolute Maximum Ratings and to prevent non-conformance due to supply rail instability.
Is the AT27C512R-45RC pin-compatible with the AT27C512-45RC?
Yes, the AT27C512R-45RC is functionally and pin-compatible with the earlier AT27C512-45RC. The "R" suffix denotes the revised version with enhanced reliability features (e.g., 2,000V ESD, 200 mA latchup immunity) and identical pinout, timing, and electrical specifications. Both share the same SOIC-28 footprint, A0–A15/O0–O7/CE/OE/VCC/GND signal mapping, and AC/DC characteristics. Migration requires no PCB changes - only verification that the Rapid™ programming algorithm and ID code features align with existing production tooling.
What is the purpose of the OE/VPP pin on the AT27C512R-45RC?
The OE/VPP pin on the AT27C512R-45RC serves a dual function: during read mode, it acts as Output Enable (OE), and during programming, it accepts 13.0 V as Programming Voltage (VPP). In read operation, OE/VPP must be driven low to enable O0–O7 outputs; when high, outputs enter high-impedance state. During programming, OE/VPP is raised to 13.0 V while CE is pulsed, activating internal high-voltage programming circuitry. This dual-role design reduces pin count while maintaining JEDEC-standard control signaling - a key feature distinguishing the AT27C512R-45RC from simpler single-function EPROMs.
AT27C512R-45RC 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:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOIC
AT27C512R-45RC FAQ
1.How can I place an order for AT27C512R-45RC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C512R-45RC 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-45RC reliable?
The price and inventory of AT27C512R-45RC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C512R-45RC is usually 5 days.
3.What payment methods are accepted for AT27C512R-45RC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C512R-45RC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C512R-45RC?
AT27C512R-45RC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C512R-45RC 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-45RC?
For technical support, including AT27C512R-45RC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C512R-45RC requirements.
6.How does Aetrix verify that AT27C512R-45RC is sourced from the original manufacturer or authorized distributors?
All AT27C512R-45RC 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-45RC meets industry standards.
7.What is the process for return or replacement of AT27C512R-45RC?
All AT27C512R-45RC units undergo pre-shipment inspection (PSI). If there is an issue with AT27C512R-45RC, 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-45RC part is unused and in its original packaging.
Return procedure for AT27C512R-45RC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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