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Microchip Technology AT27C512R-12TC
- Part No.:
- AT27C512R-12TC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
AT27C512R-12TC.pdf
- Description:
- IC EPROM 512KBIT PARALLEL 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,146
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Product details
Overview
AT27C512R-12TC from Microchip Technology (formerly Atmel) is a 512 Kbit (64K × 8) one-time programmable EPROM designed for nonvolatile firmware storage in embedded microprocessor systems. It features 45 ns read access time, 5V ±10% single-supply operation, and JEDEC-standard 28-lead TSOP packaging. Used in boot code storage for industrial controllers where reliability and zero-refresh persistence are critical.
For engineers reviewing the AT27C512R-12TC datasheet, AT27C512R-12TC pinout, AT27C512R-12TC application, or AT27C512R-12TC equivalent, key selection criteria include verified 45 ns tACC timing at commercial temperature range (0°C to 70°C), TSOP package footprint compatibility, OTP programming voltage requirements (VPP = 13.0 V), and CMOS/TTL I/O level compatibility with legacy 8-bit bus interfaces.
Technical Context
The AT27C512R-12TC implements a parallel-addressed OTP EPROM architecture with dual-line control (CE and OE/VPP) enabling bus contention avoidance in shared-data-bus systems. Its internal organization is strictly 64K × 8, with no internal address multiplexing or serial interface logic.
It supports two distinct operational modes: standard read mode (VPP = VIL) requiring only 5V supply, and rapid programming mode (VPP = 13.0 V, VCC = 6.5 V) using 100 µs CE pulses. Product identification is accessed via dedicated A9 high-voltage decode (12.0 V ±0.5 V) and A0 toggling, independent of normal read functionality.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 524,288 bits (64K × 8), fixed parallel organization - no page or sector addressing required. |
| Read Access Time | 45 ns max (tACC), enabling direct connection to 22 MHz Z80 or 80C88 buses without wait states. |
| Supply Voltage | 5V ±10% (4.5V–5.5V) for read mode; 6.5V ±0.25V required during programming - mandates separate VCC rail control. |
| Active Current | 20 mA max at 5 MHz read frequency - compatible with legacy 5V logic power budgets. |
| Standby Current | 100 µA max (CMOS CE disable) - suitable for low-power hold states in battery-backed systems. |
| Programming Voltage | VPP = 13.0 V ±0.25V applied to OE/VPP pin - requires external HV generator, not supplied by host MCU. |
| ESD Protection | 2,000V HBM - sufficient for manual handling in production without special ESD controls. |
| Latchup Immunity | 200 mA - withstands transient overcurrent events on I/O or supply pins without destructive latchup. |
Pinout & Package
AT27C512R-12TC is packaged in a 28-lead Thin Small Outline Package (TSOP, Type 1, JEDEC MO-153AA), 8.1 mm × 13.7 mm body, 0.55 mm pitch, gull-wing leads. Pin 1 marked by index notch; pin 14 = GND, pin 28 = VCC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A15 | Address Inputs | 16-bit parallel address bus - fully decoded internally; no external address latching needed. |
| O0–O7 | Data Outputs | True TTL/CMOS-compatible bidirectional outputs - drive 2.1 mA low / -400 µA high per pin. |
| CE | Chip Enable | Active-low chip select - must be stable before address setup; controls device enable/disable state. |
| OE/VPP | Output Enable / Programming Voltage | Dual-function pin: VIL enables output buffer in read mode; 13.0 V enables programming mode - cannot be left floating. |
| GND | Ground Reference | Pins 14 and 21 are ground terminals - both must be connected for signal integrity and thermal dissipation. |
| VCC | Power Supply | Pin 28 supplies all internal logic and array - decoupling capacitor (0.1 µF ceramic) required adjacent to pin. |
| NC | No Connect | Pins 7, 8, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 22, 23, 24, 25, 26, 27 have no internal connection - must remain unconnected. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time - reduces firmware burn time by >90% vs. legacy EPROMs, enabling high-throughput manufacturing. |
| Integrated Product Identification Code | Manufacturer ID (0x1E) and Device Code (0x0D) readable via A9=12.0 V and A0 toggle - ensures automated programmer compatibility and traceability. |
| Two-Line Control Architecture | Independent CE and OE/VPP pins - eliminates bus contention in multi-device memory maps without external arbitration logic. |
| High-Reliability CMOS Process | 2,000V ESD protection and 200 mA latchup immunity - certified for industrial environments with frequent board handling and noisy power rails. |
| Temperature Range Support | Commercial (0°C to 70°C) grade - validated for stable operation across full range with no derating of tACC or ICC parameters. |
Applications
| Industrial PLC Firmware Storage | Legacy PC BIOS ROM |
|---|---|
Use Scenario: Storing ladder logic execution firmware in programmable logic controllers deployed in factory automation cabinets. IC Role / Device Role / Timing Role: Nonvolatile boot memory providing deterministic 45 ns instruction fetch latency to 80C188-based CPU subsystems. Use Value: Eliminates need for battery-backed SRAM or slow serial flash, ensuring instant-on operation after power cycle with zero firmware corruption risk. | Use Scenario: Holding POST and initialization routines in early x86-based industrial PCs with ISA bus architecture. IC Role / Device Role / Timing Role: Parallel-mapped ROM mapped to 0xF0000–0xFFFFF address space, directly executed by Intel 80286 CPU. Use Value: Matches exact timing and voltage interface requirements of 1990s-era chipset designs, avoiding adapter logic or level-shifting components. |
| Medical Device Bootloader | Avionics Configuration Memory |
Use Scenario: Storing immutable bootloader code in Class II medical infusion pumps requiring FDA 21 CFR Part 11 compliance. IC Role / Device Role / Timing Role: OTP-locked configuration memory preventing runtime modification - used during cold start prior to RAM initialization. Use Value: Provides tamper-evident firmware origin verification via integrated ID code, satisfying regulatory audit requirements for software integrity. | Use Scenario: Holding flight-critical configuration tables (e.g., sensor calibration offsets, actuator limits) in airborne data acquisition units. IC Role / Device Role / Timing Role: Read-only memory accessed during pre-flight self-test sequence under DO-160E environmental stress conditions. Use Value: Validated for operation up to 70°C ambient with no parameter drift - ensures deterministic read timing during thermal soak testing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C512-12DC | Same 64K×8 OTP EPROM, 45 ns access, but uses 28-pin PDIP (not TSOP); VPP = 12.5 V ±0.5 V. | Requires PCB redesign for through-hole mounting; lacks TSOP thermal profile for convection-cooled enclosures. | Select only if legacy PDIP footprint reuse is mandatory and board re-spin is unacceptable. |
| MX27C512-12PC | Functionally identical timing and pinout, but rated for industrial temperature (-40°C to +85°C); same 28-pin TSOP package. | Validated for wider thermal range - suitable for outdoor or under-hood deployment where AT27C512R-12TC's 0°C lower limit is insufficient. | Choose when operating environment exceeds 0°C minimum; otherwise, AT27C512R-12TC offers cost advantage for commercial-grade use. |
Compared with AM27C512-12DC and MX27C512-12PC, the AT27C512R-12TC provides optimal cost-performance balance for commercial-temperature, surface-mount firmware storage - its TSOP package enables higher board density than PDIP, while avoiding the premium pricing of extended-temperature variants unless thermally mandated.
Availability
AT27C512R-12TC is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy PC BIOS ROM replacement, and medical device bootloader applications requiring stable component supply across multi-year production cycles.
Supply support for AT27C512R-12TC 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 product support, datasheet documentation, and long-term supply commitment for legacy Atmel memory devices.
The AT27C512R-12TC belongs to Atmel's 27C-series OTP EPROM family, engineered specifically for reliable, low-cost, nonvolatile code storage in resource-constrained 8-bit and 16-bit microprocessor systems.
FAQ
What is the maximum allowed VPP voltage for programming the AT27C512R-12TC?
The AT27C512R-12TC requires OE/VPP = 13.0 V ± 0.25 V during programming, as specified in the DC Programming Characteristics table. Exceeding 13.25 V risks oxide breakdown in the floating-gate cells, while voltages below 12.75 V may cause incomplete programming and subsequent read failures. This voltage must be applied only during the CE pulse window and removed before returning to read mode.
Can the AT27C512R-12TC be used in place of an EEPROM in a system design?
No, the AT27C512R-12TC is a one-time programmable EPROM and cannot be electrically erased or rewritten. Unlike EEPROMs, it lacks on-chip erase circuitry and requires UV exposure for erasure - which the AT27C512R-12TC package does not support (no quartz window). Substituting it for EEPROM will prevent field firmware updates and violate functional requirements for reprogrammable memory.
Does the AT27C512R-12TC require external decoupling capacitors, and if so, what values?
Yes, the AT27C512R-12TC requires two decoupling capacitors per device: a 0.1 µF high-frequency ceramic capacitor placed between VCC and GND as close as possible to pins 28 and 14, and a 4.7 µF bulk electrolytic capacitor located near the power entry point of the EPROM array. These are mandatory per the System Considerations section to suppress transient excursions during CE switching that could exceed absolute maximum ratings.
How is the Integrated Product Identification Code read from the AT27C512R-12TC?
The AT27C512R-12TC ID code is read by setting A9 = 12.0 V ± 0.5 V (VID), holding A1–A15 = VIL, and toggling A0 between VIL (to read Manufacturer ID = 0x1E) and VIH (to read Device Code = 0x0D). All other inputs must be stable, and OE/VPP must be held at VIL. The 8-bit ID appears on O0–O7 within tACC after address stabilization - no special programming mode is required.
Is the AT27C512R-12TC pin-compatible with the AT27C512-12TC?
Yes, the AT27C512R-12TC is a revised version of the AT27C512-12TC with identical pinout, timing, and electrical specifications. The "R" suffix denotes enhanced reliability screening and updated Rapid™ programming algorithm, but retains full mechanical and functional compatibility - including TSOP-28 footprint, address/data bus mapping, and CE/OE/VPP control logic.
AT27C512R-12TC 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:
- 120 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-12TC FAQ
1.How can I place an order for AT27C512R-12TC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C512R-12TC 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-12TC reliable?
The price and inventory of AT27C512R-12TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C512R-12TC is usually 5 days.
3.What payment methods are accepted for AT27C512R-12TC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C512R-12TC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C512R-12TC?
AT27C512R-12TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C512R-12TC 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-12TC?
For technical support, including AT27C512R-12TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C512R-12TC requirements.
6.How does Aetrix verify that AT27C512R-12TC is sourced from the original manufacturer or authorized distributors?
All AT27C512R-12TC 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-12TC meets industry standards.
7.What is the process for return or replacement of AT27C512R-12TC?
All AT27C512R-12TC units undergo pre-shipment inspection (PSI). If there is an issue with AT27C512R-12TC, 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-12TC part is unused and in its original packaging.
Return procedure for AT27C512R-12TC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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