My Inquiry
My Account
Microchip Technology AT27C512R-55JI
- Part No.:
- AT27C512R-55JI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT27C512R-55JI.pdf
- Description:
- IC EPROM 512KBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:2,343
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT27C512R-55JI from Microchip Technology (formerly Atmel) is a 512 Kbit (64K × 8) one-time programmable EPROM designed for firmware storage in microprocessor-based systems. It delivers 55 ns read access time, operates on a single 5V ±10% supply, and supports industrial temperature range (–40°C to +85°C) in a 28-lead SOIC package. Used for boot code and configuration data in embedded controllers and legacy industrial controllers.
For engineers reviewing the AT27C512R-55JI datasheet, AT27C512R-55JI pinout, AT27C512R-55JI application, or AT27C512R-55JI equivalent, key selection criteria include read speed grade (-55), industrial temperature rating, OTP reliability, JEDEC-standard SOIC packaging, and compatibility with CE/OE dual-control bus interfaces in 8-bit microcontroller systems.
Technical Context
The AT27C512R-55JI implements a CMOS-based OTP EPROM architecture with two-line control (CE and OE/VPP), enabling bus contention avoidance in shared-data-bus systems. Its address space spans A0–A15 (16-bit), supporting full 64K-byte random access without wait states at ≤5 MHz system clock speeds.
It features Rapid™ programming with 100 µs/byte typical pulse width at VCC = 6.5 V and OE/VPP = 13.0 V, plus integrated product identification (Manufacturer ID: 0x1E, Device ID: 0x0D) readable via A9 high-voltage mode. ESD protection exceeds 2,000 V and latchup immunity is rated at 200 mA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 512 Kbit (64K × 8) - supports full 8-bit data bus interface with no byte-width limitations |
| Read Access Time | 55 ns - enables direct connection to 5 MHz microprocessors without WAIT-state insertion |
| Supply Voltage | 5 V ±10% - compatible with standard TTL/CMOS logic rails; no auxiliary voltage required for read mode |
| Operating Temperature | –40°C to +85°C - qualified for industrial environments including factory automation and motor control systems |
| Standby Current | ≤100 µA - minimizes power draw during idle cycles in battery-backed or low-power standby modes |
| Active Current | ≤20 mA at 5 MHz - supports sustained read throughput without thermal derating in compact PCB layouts |
| Input Compatibility | CMOS and TTL - eliminates level-shifting requirements when interfacing with legacy 8051, Z80, or 68K-family microcontrollers |
Pinout & Package
AT27C512R-55JI is supplied in a 28-lead plastic gull-wing small outline integrated circuit (SOIC) package per JEDEC MS-012 standard, 0.330" body width, with pin 1 index mark and standard 1.27 mm pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A15 | Address Inputs | 16-bit address bus interface; fully decoded to select any of 64K bytes independently |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus outputs; CMOS/TTL-compatible drive strength (IOH = –400 µA, IOL = 2.1 mA) |
| CE | Chip Enable | Primary device select; must be low for read or program operations; controls active/standby current transition |
| OE/VPP | Output Enable / Programming Voltage | Low during read (enables output drivers); high at 12–13 V during programming (VPP mode) |
| VCC | Power Supply | +5 V ±10% supply input; requires local 0.1 µF ceramic decoupling per device per datasheet layout guidance |
| GND | Ground Reference | Signal and power return; must be connected to low-impedance ground plane to maintain noise margin and timing integrity |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical pulse width reduces production programming time by >5× vs. legacy EPROMs; includes auto-verify loop up to 10 retries per byte |
| Integrated Product Identification Code | Manufacturer ID (0x1E) and Device ID (0x0D) accessible via A9 = 12 V and A0 toggle - enables automated programmer validation and BOM traceability |
| Two-Line Control Architecture | Independent CE and OE/VPP pins allow flexible bus arbitration; prevents contention during multi-device memory mapping in 8-bit systems |
| High-Reliability Process | 2,000 V HBM ESD rating and 200 mA latchup immunity ensure robustness in manufacturing handling and field-deployed industrial equipment |
| JEDEC-Standard Packaging | 28-lead SOIC (28R) footprint matches industry-replaceable footprint; supports reflow and wave soldering per J-STD-020 |
Applications
| Industrial PLC Firmware Storage | Legacy Automotive ECU Boot ROM |
|---|---|
Use Scenario: Storing fixed ladder logic firmware and I/O configuration tables in programmable logic controllers deployed in factory-floor environments with wide ambient temperature swings. IC Role / Device Role / Timing Role: Nonvolatile boot memory providing immediate instruction fetch upon power-up; accessed via 8-bit parallel bus with deterministic 55 ns latency. Use Value: Eliminates reliance on external serial EEPROM or flash, reducing BOM count and avoiding wear-out concerns inherent in reprogrammable media. |
Use Scenario: Holding immutable engine calibration maps and startup routines in pre-OBD-II automotive control units operating in under-hood conditions. IC Role / Device Role / Timing Role: OTP EPROM serving as primary read-only instruction store; synchronized to 5 MHz Z80 or 8051 derivatives with no wait-state overhead. Use Value: Guarantees firmware integrity over vehicle lifetime-immune to bit corruption from EMI, power glitches, or accidental rewrites. |
| Medical Instrument Bootloader | Avionics System Configuration Memory |
Use Scenario: Storing certified bootloader code and safety-critical initialization sequences in Class II medical devices requiring regulatory audit trails and revision-controlled firmware. IC Role / Device Role / Timing Role: Secure, unalterable memory element verified at production test; accessed during cold-start sequence before RAM initialization. Use Value: Meets IEC 62304 clause 5.5.2 for fixed software components-no field update capability required or permitted. |
Use Scenario: Retaining aircraft-specific configuration parameters (e.g., sensor scaling, trim offsets) in flight management computers where data persistence must survive 20+ year service life. IC Role / Device Role / Timing Role: Radiation-tolerant OTP storage accessed during power-on self-test (POST); supports MIL-STD-704 compliant 5 V supply rails. Use Value: Provides guaranteed data retention >20 years at +85°C per JEDEC JESD22-A108, exceeding avionics shelf-life requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C512-55DC | Same 512 Kbit × 8 organization and 55 ns speed grade; uses AMD's CMOS process with 150 µA max standby current (vs. 100 µA for AT27C512R-55JI) | Identical pinout and AC timing; requires same 12 V VPP but lacks integrated ID code | Select when legacy AMD ecosystem support or second-source qualification is mandated; verify ID-code-dependent programming tool compatibility |
| MX27C512-55PC | Macronix variant with identical 28-pin PDIP package option; 25 mA active current (vs. 20 mA); no PLCC/SOIC/TSOP variants offered for -55 grade | Requires PCB redesign if migrating from SOIC (28R) to PDIP (28P6); same CE/OE control but no Rapid™ algorithm support | Prefer only for through-hole prototyping or legacy board refresh where SOIC footprint is unavailable |
Compared with AM27C512-55DC and MX27C512-55PC, the AT27C512R-55JI offers lower standby current, integrated ID coding for automated programming, and broader JEDEC package support-including the SOIC variant specified by this part number-making it optimal for space-constrained industrial PCBs requiring long-term firmware immutability.
Availability
AT27C512R-55JI is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy automotive ECU boot ROM, and medical instrument bootloader applications requiring stable component supply across extended product lifecycles.
Supply support for AT27C512R-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
Microchip Technology acquired Atmel in 2016 and maintains full support for legacy Atmel memory products. The company specializes in secure, reliable microcontrollers and nonvolatile memory solutions for industrial and automotive markets.
The AT27C512R belongs to Atmel's 27C-series OTP EPROM family, engineered for high-reliability firmware storage in systems where code immutability, long-term data retention, and deterministic timing are critical design requirements.
FAQ
What is the maximum operating frequency supported by AT27C512R-55JI?
The AT27C512R-55JI does not operate at a clock frequency itself but supports system bus frequencies up to 5 MHz. Its 55 ns read access time ensures zero-wait-state operation with microprocessors running at ≤5 MHz, such as the 8051 or Z80 derivatives commonly used in legacy designs where AT27C512R-55JI is deployed.
Does AT27C512R-55JI require a programming voltage higher than VCC during normal operation?
No. During normal read operation, AT27C512R-55JI requires only a single 5 V ±10% supply on VCC. The OE/VPP pin functions as Output Enable (low) during reads. Programming voltage (12–13 V) is applied only to OE/VPP during programming mode and is never present during system runtime-AT27C512R-55JI remains a 5 V-only device in application circuits.
Is AT27C512R-55JI pin-compatible with other speed grades like AT27C512R-45JI or AT27C512R-70JI?
Yes. All AT27C512R speed grades-including AT27C512R-45JI, AT27C512R-55JI, and AT27C512R-70JI-share identical pinout, package dimensions, and DC/AC interface behavior. The only difference is read access time (45 ns, 55 ns, or 70 ns), allowing drop-in replacement where timing margins permit; AT27C512R-55JI fits any design qualified for the -45 or -70 variants.
Can AT27C512R-55JI be reprogrammed after initial programming?
No. AT27C512R-55JI is a one-time programmable (OTP) EPROM. Once programmed, its memory cells cannot be erased or rewritten. This design ensures absolute firmware integrity-critical for safety- or mission-critical applications where accidental or malicious modification must be physically impossible. AT27C512R-55JI is not UV-erasable nor electrically erasable.
What decoupling capacitance is required for stable operation of AT27C512R-55JI?
Per the AT27C512R datasheet, each AT27C512R-55JI device 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, an additional 4.7 µF bulk electrolytic capacitor should be placed near the power entry point to suppress low-frequency rail droop-both are mandatory for meeting AC timing specs and preventing transient-induced non-conformance.
AT27C512R-55JI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- 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:
- 55 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (13.97x11.43)
AT27C512R-55JI FAQ
1.How can I place an order for AT27C512R-55JI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C512R-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 AT27C512R-55JI reliable?
The price and inventory of AT27C512R-55JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C512R-55JI is usually 5 days.
3.What payment methods are accepted for AT27C512R-55JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C512R-55JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C512R-55JI?
AT27C512R-55JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C512R-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 AT27C512R-55JI?
For technical support, including AT27C512R-55JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C512R-55JI requirements.
6.How does Aetrix verify that AT27C512R-55JI is sourced from the original manufacturer or authorized distributors?
All AT27C512R-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 AT27C512R-55JI meets industry standards.
7.What is the process for return or replacement of AT27C512R-55JI?
All AT27C512R-55JI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C512R-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 AT27C512R-55JI part is unused and in its original packaging.
Return procedure for AT27C512R-55JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT27C512R-55JI Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
