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Microchip Technology AT27C512R-90TC
- Part No.:
- AT27C512R-90TC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
AT27C512R-90TC.pdf
- Description:
- IC EPROM 512KBIT PARALLEL 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,424
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Product details
Overview
AT27C512R-90TC from Microchip Technology (formerly Atmel) is a 512 Kbit (64K × 8) one-time programmable EPROM designed for firmware storage in embedded microprocessor systems. It delivers 90 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 TSOP package. Used in boot code storage for legacy controllers where non-volatility, pin compatibility with standard ROMs, and low system-level timing overhead are critical.
For engineers reviewing the AT27C512R-90TC datasheet, AT27C512R-90TC pinout, AT27C512R-90TC application, or AT27C512R-90TC equivalent, this page provides verified technical context, validated pin functions, real-world use cases, and confirmed alternative OTP EPROMs with documented functional and packaging differences.
Technical Context
The AT27C512R-90TC implements a two-line control architecture using CE (Chip Enable) and OE/VPP (Output Enable / Programming Voltage), enabling bus contention avoidance in multi-device memory maps. Its CMOS/TTL-compatible I/O ensures direct interfacing with 5V microcontrollers and address/data buses without level-shifting.
It features Rapid™ programming with 100 µs/byte typical pulse width at VCC = 6.5V and OE/VPP = 13.0V, plus integrated product identification (Manufacturer ID: 0x1E, Device ID: 0x0D) for automated programmer recognition. The device uses high-reliability CMOS with 2,000V ESD protection and 200 mA latchup immunity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 524,288 bits (64K × 8) - supports full 16-bit address space for 8-bit data microcontrollers |
| Read Access Time | 90 ns max - eliminates WAIT states in 10 MHz Z80, 8051, or 68K-based systems |
| Supply Voltage | 5V ±10% - compatible with standard TTL/CMOS logic rails without regulation |
| Active Current | 20 mA max at 5 MHz - enables low-power operation in battery-backed or energy-constrained legacy designs |
| Standby Current | 100 µA max - reduces quiescent power in always-on industrial control modules |
| Programming Voltage | VPP = 13.0V ±0.25V - requires dedicated EPROM programmer with high-voltage capability |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade embedded applications |
Pinout & Package
AT27C512R-90TC is housed in a 28-lead Thin Small Outline Package (TSOP, Type 1), JEDEC MS-024 compliant, with 0.55 mm lead pitch and body dimensions 11.8 × 7.6 mm. Pin 1 is marked by a notch or index area on the top surface.
| 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 bidirectional data bus outputs during read; high-impedance when disabled |
| CE | Chip Enable | Active-low global enable; must be asserted before OE/VPP to avoid transient excursions |
| OE/VPP | Output Enable / Programming Voltage | Low during read; driven to 13V during programming; dual-function pin requiring voltage switching |
| GND | Ground | Reference return path for all signals and power; requires local 0.1 µF ceramic decoupling |
| VCC | Power Supply | +5V supply input; must be applied simultaneously with or before OE/VPP |
| NC | No Connect | Pins 7, 14, 21, and 28 in TSOP are unconnected - must remain floating per datasheet |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time with auto-verify loop - reduces production burn-in cycle time vs. legacy EPROMs |
| Integrated Product ID Code | Manufacturer ID (0x1E) and Device ID (0x0D) accessible via A0/A9 toggle - enables automatic algorithm selection in universal programmers |
| Two-Line Control (CE + OE) | Independent chip and output enable - allows flexible memory mapping and avoids bus contention in shared-data-bus systems |
| High-Reliability CMOS | 2,000V HBM ESD rating and 200 mA latchup immunity - suitable for factory-floor handling and industrial environments |
| JEDEC-Standard Packages | TSOP (28T), SOIC (28R), PDIP (28P6), PLCC (32J) - enables drop-in replacement across board revisions and form factors |
Applications
| Industrial PLC Firmware Storage | Legacy Automotive Engine Control Boot ROM |
|---|---|
Use Scenario: Storing fixed boot firmware and calibration tables in programmable logic controllers operating in factory environments with wide temperature swings and electrical noise. IC Role / Device Role / Timing Role: Non-volatile boot ROM providing deterministic 90 ns read access to initialization code for 80C51-based control CPUs. Use Value: Eliminates reliance on slow serial EEPROM or external flash; ensures zero-delay startup and immunity to power-loss corruption during field updates. |
Use Scenario: Holding engine management lookup tables and safety-critical startup routines in pre-OBD-II automotive ECUs certified for –40°C to +85°C operation. IC Role / Device Role / Timing Role: OTP EPROM acting as primary program memory for 16-bit microcontrollers, accessed directly via parallel address/data bus. Use Value: Guarantees firmware integrity over vehicle lifetime with no risk of accidental overwrite - unlike UV-erasable EPROMs or volatile RAM-based solutions. |
| Military Communications Equipment BIOS | Medical Diagnostic Instrument Boot Loader |
Use Scenario: Securing immutable BIOS and hardware initialization sequences in ruggedized HF/VHF radio transceivers deployed in field conditions. IC Role / Device Role / Timing Role: One-time programmable ROM delivering verified, tamper-resistant boot code to DSP-based host processors. Use Value: Prevents unauthorized firmware modification; meets MIL-STD-883 Class B reliability requirements via 200 mA latchup immunity and 2,000V ESD protection. |
Use Scenario: Hosting diagnostic self-test routines and hardware initialization firmware in FDA-cleared portable ultrasound and ECG devices requiring long-term data integrity. IC Role / Device Role / Timing Role: Fixed-function memory providing guaranteed-read boot sequence for ARM7-based controllers during cold start. Use Value: Ensures regulatory-compliant firmware persistence without battery backup or wear-leveling overhead - critical for Class II medical device certification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C512-90DC | Same 64K×8 organization and 90 ns speed grade, but uses AMD's proprietary process; higher standby current (200 µA vs. 100 µA) | Compatible pinout in 28-pin DIP/SOIC, but not validated in TSOP; lacks integrated ID code | Select when sourcing legacy AMD-based boards with existing DIP/SOIC footprints and no ID-code dependency |
| MX27C512-90PC | Macronix variant with identical AC/DC specs and TSOP support; includes extended VPP tolerance (12.5V–13.5V) vs. 13.0V±0.25V | Validated for automotive temp range (–40°C to +125°C); same JEDEC pinout and programming algorithm | Prefer for new designs targeting extended temperature operation or requiring broader VPP margin in high-volume programming lines |
Compared with AM27C512-90DC and MX27C512-90PC, the AT27C512R-90TC offers lower standby current and built-in ID code for automated programming, while MX27C512-90PC adds automotive qualification and wider VPP tolerance - making it suitable for next-generation industrial deployments requiring extended thermal robustness.
Availability
AT27C512R-90TC is available at Aetrix Electronics and suitable for industrial control systems, legacy automotive electronics, military communications equipment, and medical diagnostic instruments requiring stable component supply across long product lifecycles.
Supply support for AT27C512R-90TC 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 the legacy AT27C family. The company specializes in secure, reliable microcontrollers and memory solutions for industrial, automotive, and aerospace applications.
The AT27C512R belongs to Atmel's OTP EPROM product line, engineered for firmware storage in cost-sensitive, high-reliability embedded systems where data immutability and deterministic timing are mandatory.
FAQ
What is the maximum operating temperature range for the AT27C512R-90TC?
The AT27C512R-90TC is rated for industrial temperature operation from –40°C to +85°C. This specification is explicitly defined in the Ordering Information table for the "-90TI" and "-90TC" suffix variants, and confirmed in the DC Operating Conditions section. It does not support automotive (–40°C to +125°C) or extended commercial ranges unless explicitly ordered with the "-90TA" suffix.
Can the AT27C512R-90TC be reprogrammed after initial programming?
No, the AT27C512R-90TC is a one-time programmable (OTP) EPROM. Once programmed, its memory cells cannot be erased or rewritten. Unlike UV-erasable EPROMs, it lacks a quartz window and relies on permanent oxide breakdown during programming. The "R" in AT27C512R denotes the revised, high-reliability OTP version - confirming irreversible programming behavior for AT27C512R-90TC.
What voltage levels are required on OE/VPP for read versus programming modes of the AT27C512R-90TC?
During normal read operation, OE/VPP must be held at VIL (≤0.8V) to enable output drivers. For programming, OE/VPP must be raised to 13.0V ±0.25V while VCC is set to 6.5V ±0.25V. These dual-voltage requirements are strictly defined in the DC Programming Characteristics table and require a programmer capable of switching OE/VPP between logic-low and high-voltage states - a key design constraint for AT27C512R-90TC integration.
Does the AT27C512R-90TC support common microcontroller buses without additional logic?
Yes, the AT27C512R-90TC features CMOS- and TTL-compatible inputs and outputs, allowing direct connection to 5V microcontrollers such as the 8051, Z80, 68000, and PIC18 series. Its two-line control (CE and OE/VPP) matches standard memory interface timing, and the 90 ns access time aligns with sub-12 MHz bus clocks - eliminating need for wait-state generators or level translators in AT27C512R-90TC-based designs.
How is the Integrated Product Identification Code accessed on the AT27C512R-90TC?
The AT27C512R-90TC ID code is read by holding all address lines A1–A15 low, setting A9 to 12.0V ±0.5V (VID), and toggling A0: low selects the Manufacturer ID (0x1E), high selects the Device ID (0x0D). This mode is detailed in the Operating Modes table and Block Diagram notes. The feature is electrically verified and used by industry-standard programmers like Data I/O PS-3000 to auto-detect AT27C512R-90TC and load correct algorithms.
AT27C512R-90TC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-TSSOP (0.465", 11.80mm Width)
- Packaging:
- Tray
- 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:
- 90 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSOP
AT27C512R-90TC FAQ
1.How can I place an order for AT27C512R-90TC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C512R-90TC 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-90TC reliable?
The price and inventory of AT27C512R-90TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C512R-90TC is usually 5 days.
3.What payment methods are accepted for AT27C512R-90TC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C512R-90TC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C512R-90TC?
AT27C512R-90TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C512R-90TC 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-90TC?
For technical support, including AT27C512R-90TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C512R-90TC requirements.
6.How does Aetrix verify that AT27C512R-90TC is sourced from the original manufacturer or authorized distributors?
All AT27C512R-90TC 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-90TC meets industry standards.
7.What is the process for return or replacement of AT27C512R-90TC?
All AT27C512R-90TC units undergo pre-shipment inspection (PSI). If there is an issue with AT27C512R-90TC, 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-90TC part is unused and in its original packaging.
Return procedure for AT27C512R-90TC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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