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Microchip Technology AT27C256R-15JC
- Part No.:
- AT27C256R-15JC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT27C256R-15JC.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
AT27C256R-15JC from Atmel is a 256K-bit (32K × 8) one-time programmable EPROM with 150 ns maximum read access time, 5V ±10% single-supply operation, and JEDEC-standard 28-lead PDIP packaging. It delivers TTL/CMOS-compatible I/O, 100 µA max standby current, and supports firmware storage in microprocessor-based embedded systems requiring non-volatile, pin-verified code retention.
For engineers reviewing the AT27C256R-15JC datasheet, AT27C256R-15JC pinout, AT27C256R-15JC application, or AT27C256R-15JC equivalent, key selection criteria include verified 150 ns tACC timing, VPP-programmable OTP architecture, JEDEC 28P6 package compatibility, and industrial-grade temperature support up to +85°C.
Technical Context
The AT27C256R-15JC implements a parallel-addressed OTP EPROM architecture with dual-line control (CE/OE) enabling bus contention avoidance in shared-data-bus systems. Its internal decoding logic supports full 15-bit address range (A0–A14) and 8-bit bidirectional data outputs (O0–O7), with NC pins at A12 and VPP in read mode.
It operates exclusively in 5V read mode without auxiliary voltage-VPP is required only during programming-and features integrated product identification (manufacturer code 0x1E, device code 0x8C) accessible via A9/VH and A0 toggling, used by standard programmers for algorithm auto-selection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32K × 8) - supports full 8-bit microcontroller instruction/data fetch without banking |
| Read Access Time (tACC) | 150 ns max - ensures no WAIT states required on 6.67 MHz Z80 or 8 MHz 8051 systems |
| Supply Voltage | 5V ±10% - compatible with legacy TTL/CMOS logic rails; no separate VPP needed in read mode |
| Standby Current (ISB1) | 100 µA max - enables low-power hold state in battery-backed or intermittent-read applications |
| Active Current (ICC) | 20 mA max at 5 MHz - matches typical 8-bit MCU bus loading without local regulation |
| Input Compatibility | TTL/CMOS - eliminates level-shifter requirement when interfacing with 74LS, 74HC, or 80Cxx families |
| ESD Protection | 2,000V HBM - meets industrial handling requirements per ANSI/ESDA/JEDEC JS-001 |
Pinout & Package
AT27C256R-15JC is packaged in a 28-lead, 0.600" wide plastic dual in-line package (PDIP), JEDEC MS-011 AB compliant, with 0.100" lead pitch and through-hole mounting.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit parallel address bus; fully decoded to select one of 32,768 bytes |
| O0–O7 | Data Outputs | 8-bit tristate CMOS/TTL-compatible data bus; driven only when CE=OE=low |
| CE | Chip Enable | Active-low global enable; places outputs in high-impedance state when high |
| OE | Output Enable | Active-low output gate; allows shared-bus operation with other peripherals |
| VPP | Programming Voltage | 12.0V ±0.5V input during programming only; must be applied after VCC and removed before VCC |
| GND | Ground Reference | Signal and power return; requires local 0.1 µF ceramic decoupling per device |
| VCC | Power Supply | +5V ±10% main supply; powers all logic and memory array in read mode |
| NC | No Connect | Pins 1 and 17 are unconnected; no internal bonding or function |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical - reduces full-device programming time to under 3.3 seconds vs. legacy 1 ms/byte methods |
| Integrated Product ID Code | Manufacturer ID 0x1E + Device ID 0x8C - enables automatic algorithm selection in production programmers |
| Two-Line Control Architecture | Separate CE and OE inputs - permits flexible bus arbitration and partial-memory disable without address decoding |
| High-Reliability Process | 200 mA latchup immunity - prevents destructive SCR triggering during transient overvoltage events |
| Temperature Range Support | -40°C to +85°C (industrial grade) - validated for extended operation in motor control and PLC environments |
Applications
| Industrial PLC Firmware Storage | Legacy Microcontroller Boot ROM |
|---|---|
Use Scenario: Storing ladder logic execution firmware in DIN-rail mounted programmable logic controllers operating continuously in factory-floor environments. IC Role / Device Role / Timing Role: Non-volatile boot memory mapped to CPU address space; accessed at power-on reset and during runtime instruction fetch. Use Value: 150 ns tACC eliminates WAIT-state insertion, maintaining deterministic 6.67 MHz scan cycle timing across temperature extremes. | Use Scenario: Providing fixed startup code for Z80, 8085, or 68000-based instrumentation systems where EEPROM wear-out or SRAM volatility is unacceptable. IC Role / Device Role / Timing Role: Read-only instruction memory with direct parallel bus interface; no write-cycle overhead or refresh management. Use Value: Single 5V supply simplifies power design; 100 µA standby draw extends battery backup duration in maintenance-mode operation. |
| Automotive ECU Calibration Data | Medical Device Configuration Memory |
Use Scenario: Holding engine calibration maps and sensor compensation tables in Tier-1 automotive ECUs certified to AEC-Q100 Grade 2 (-40°C to +105°C). IC Role / Device Role / Timing Role: OTP configuration store accessed during cold-start initialization; immune to accidental overwrite or corruption. Use Value: 2,000V ESD protection withstands assembly line handling; rapid programming enables final-test calibration burn-in. | Use Scenario: Storing FDA-mandated device configuration parameters (e.g., alarm thresholds, safety limits) in Class II medical analyzers requiring immutable settings. IC Role / Device Role / Timing Role: Tamper-proof, non-rewritable memory holding critical operational constants verified at manufacturing test. Use Value: One-time programmability guarantees parameter integrity across 10+ year service life; no field update risk or firmware rollback vulnerability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C256B-15J | 150 ns tACC, same 32K×8 organization, but uses AMD's process with 25 mA ICC and no integrated ID code | Lacks product identification byte; requires manual algorithm selection in programmers | Preferred when cost sensitivity outweighs programmer automation needs |
| MX27C256-15PC | 150 ns tACC, identical pinout and DC specs, but rated only for commercial temp (0°C to 70°C) | Not qualified for industrial or automotive use; lacks -40°C startup guarantee | Select only for lab prototypes or non-critical consumer electronics |
Compared with AM27C256B-15J and MX27C256-15PC, the AT27C256R-15JC uniquely combines industrial temperature qualification, integrated ID code for automated programming, and 100 µA standby current-making it optimal for production-grade embedded systems where reliability, test efficiency, and long-term supply stability are mandatory.
Availability
AT27C256R-15JC is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy microcontroller boot ROM, and automotive ECU calibration data applications requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for AT27C256R-15JC 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) designed high-reliability non-volatile memory and microcontrollers for industrial, automotive, and computing applications before its 2016 acquisition.
The AT27C256R-15JC belongs to Atmel's 27C-series OTP EPROM product line, engineered specifically for cost-sensitive, high-volume embedded systems needing guaranteed code immutability, JEDEC-standard packaging, and seamless integration into legacy 8-bit and 16-bit microprocessor buses.
FAQ
What is the maximum read access time specified for the AT27C256R-15JC?
The AT27C256R-15JC has a maximum read access time (tACC) of 150 ns under industrial temperature conditions (-40°C to +85°C) and 5V ±10% supply. This value is guaranteed across the full operating range and is measured from address valid to valid data output with CE and OE both asserted low. The "15" in the part number directly denotes this 150 ns speed grade, distinguishing it from faster variants like the -45JC (45 ns) or slower ones like the -12JC (120 ns). AT27C256R-15JC meets this spec without requiring external WAIT-state generation on most 8-bit microprocessor buses.
Does the AT27C256R-15JC require a programming voltage (VPP) during normal read operation?
No, the AT27C256R-15JC operates in read mode using only a single 5V ±10% supply (VCC); VPP is required exclusively during programming and verification cycles. During read, VPP is left unconnected or tied to VCC only if the system design mandates it for pin compatibility-no current flows into VPP in read mode. The AT27C256R-15JC datasheet explicitly states that VPP must be applied after VCC and removed before VCC during programming to prevent latchup. In normal operation, VPP is electrically isolated from the memory core.
What package type does the AT27C256R-15JC use, and is it RoHS-compliant?
The AT27C256R-15JC uses a 28-lead, 0.600" wide plastic dual in-line package (PDIP), designated as package code "28P6" per Atmel's ordering information. This is a through-hole, JEDEC MS-011 AB standard package. While the original Atmel datasheet predates RoHS enforcement, current production lots of AT27C256R-15JC supplied by authorized distributors are manufactured to RoHS Directive 2011/65/EU standards, with lead-free terminations and compliant molding compounds. Aetrix Electronics provides full material declarations upon request for AT27C256R-15JC shipments.
Can the AT27C256R-15JC be used as a direct replacement for the AT27C256-15JC?
Yes-the AT27C256R-15JC is the enhanced revision of the AT27C256-15JC, with identical pinout, timing, and DC specifications. The "R" suffix indicates improved reliability features including higher ESD protection (2,000V vs. 1,000V), stronger latchup immunity (200 mA vs. 100 mA), and tighter AC parameter distributions. All AT27C256R-15JC units are backward compatible with legacy AT27C256-15JC designs; no PCB or firmware changes are required. The AT27C256R-15JC supersedes the non-R version in all new designs and is the only version currently in active production.
What is the purpose of the Integrated Product Identification Code in the AT27C256R-15JC?
The Integrated Product Identification Code in the AT27C256R-15JC provides two factory-programmed bytes-manufacturer ID (0x1E) and device ID (0x8C)-accessible via dedicated address/control sequencing (A9 = 12.0V, A0 toggled). This code enables industry-standard EPROM programmers to automatically detect the device type and apply correct programming algorithms, voltages, and verification sequences-eliminating manual setup errors. For the AT27C256R-15JC, this feature reduces programming line setup time and improves first-pass yield in high-volume manufacturing, especially when mixed with other Atmel or compatible OTP devices.
AT27C256R-15JC 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:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 150 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (13.97x11.43)
AT27C256R-15JC FAQ
1.How can I place an order for AT27C256R-15JC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C256R-15JC 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 AT27C256R-15JC reliable?
The price and inventory of AT27C256R-15JC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C256R-15JC is usually 5 days.
3.What payment methods are accepted for AT27C256R-15JC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C256R-15JC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C256R-15JC?
AT27C256R-15JC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C256R-15JC 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 AT27C256R-15JC?
For technical support, including AT27C256R-15JC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C256R-15JC requirements.
6.How does Aetrix verify that AT27C256R-15JC is sourced from the original manufacturer or authorized distributors?
All AT27C256R-15JC 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 AT27C256R-15JC meets industry standards.
7.What is the process for return or replacement of AT27C256R-15JC?
All AT27C256R-15JC units undergo pre-shipment inspection (PSI). If there is an issue with AT27C256R-15JC, 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 AT27C256R-15JC part is unused and in its original packaging.
Return procedure for AT27C256R-15JC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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