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Microchip Technology AT27BV256-12RI
- Part No.:
- AT27BV256-12RI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.342", 8.69mm Width)
- Datasheet:
-
AT27BV256-12RI.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,963
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Product details
Overview
AT27BV256-12RI from Atmel is a 256K-bit (32K × 8) one-time programmable EPROM optimized for low-voltage battery-powered systems, featuring 70 ns read access time, dual supply operation (2.7–3.6V or 4.5–5.5V), and industrial temperature range (–40°C to +85°C). It delivers TTL-compatible outputs at 3.0V and supports rapid programming at 100 µs/byte.
For engineers reviewing the AT27BV256-12RI datasheet, AT27BV256-12RI pinout, AT27BV256-12RI application, or AT27BV256-12RI equivalent, key selection considerations include unregulated battery voltage support, JEDEC-standard PLCC/SOIC/TSOP package compatibility, standby current under 20 µA, and pin-for-pin equivalence with AT27C256R in read mode.
Technical Context
The AT27BV256-12RI implements a CMOS OTP EPROM architecture with two-line control (CE/OE), enabling bus contention avoidance in shared-memory systems. Its dual-voltage design allows seamless integration into mixed-supply environments-operating at 2.7–3.6V for portable applications or 4.5–5.5V for legacy 5V systems without level-shifting.
It features Rapid™ programming with 100 µs/byte typical write cycles, integrated product identification code (Manufacturer ID: 0x1E, Device ID: 0x8C), and robust ESD protection (2,000V) and latchup immunity (200 mA). Programming requires VPP = 13.0V and VCC = 6.5V, while read/standby modes operate within standard logic supply rails.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32K × 8) - supports firmware storage for microcontroller boot code or configuration data in space-constrained embedded designs. |
| Read Access Time | 70 ns max - enables direct execution from memory in high-speed 8-bit systems without wait states at 5 MHz clock rates. |
| Supply Voltage Range | 2.7V–3.6V or 4.5V–5.5V - eliminates need for voltage regulators in battery-powered devices using unregulated Li-ion or alkaline sources. |
| Standby Current | 20 µA max at VCC = 3.6V - extends battery life in always-on or infrequently accessed memory applications. |
| Operating Temperature | –40°C to +85°C - qualified for industrial control, automotive body electronics, and outdoor instrumentation. |
| Programming Speed | 100 µs/byte typical - reduces production programming time versus standard EPROMs, improving manufacturing throughput. |
| Output Compatibility | TTL- and LVTTL-compatible - interfaces directly with 5V microcontrollers and 3V logic families without external buffers. |
Pinout & Package
AT27BV256-12RI is supplied in a 28-lead 330-mil SOIC package (package code 28R), with 14 pins per side and standard JEDEC outline. Pin 1 is marked by a beveled corner; pin 14 is GND and pin 28 is VCC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word addressing; driven by microcontroller or address decoder. |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus in read mode; high-impedance during standby or output disable. |
| CE | Chip Enable | Active-low chip select; controls device activation and power state transition between active and standby. |
| OE | Output Enable | Active-low output gate; used with CE to manage bus sharing and prevent contention on shared data lines. |
| VPP | Programming Voltage | 13.0V input required only during programming; must be applied after and removed before VCC per timing constraints. |
| VCC | Power Supply | Primary logic supply; accepts 2.7–3.6V (battery) or 4.5–5.5V (standard) with internal regulation for stable core operation. |
| GND | Ground Reference | Signal and power return path; requires local 0.1 µF ceramic decoupling capacitor per device. |
Key Features
| Feature | Design Value |
|---|---|
| Unregulated Battery-Voltage™ Operation | Eliminates external DC-DC regulation for 2.7–3.6V battery inputs, reducing BOM count and PCB area in portable equipment. |
| JEDEC Pin Compatibility with AT27C256R | Enables drop-in replacement in existing 5V designs without layout changes, accelerating migration to lower-power solutions. |
| Rapid™ Programming Algorithm | Reduces programming time by >90% vs. conventional EPROMs, supporting high-yield volume production with verification loops. |
| Integrated Product Identification Code | Allows automated programmer recognition of manufacturer (0x1E) and device type (0x8C), ensuring correct algorithm and voltage selection. |
| 2,000V ESD Protection | Meets IEC 61000-4-2 Level 4 requirements for handling in assembly environments without special ESD controls. |
Applications
| Portable Medical Devices | Industrial PLC Firmware Storage |
|---|---|
Use Scenario: Battery-powered glucose meters and handheld diagnostic tools requiring nonvolatile program storage with minimal power draw between measurements. IC Role / Device Role / Timing Role: OTP EPROM storing calibrated sensor algorithms and UI firmware; accessed intermittently during startup and measurement cycles. Use Value: 20 µA standby current and 2.7V operation extend single-cell CR2032 battery life beyond 2 years in low-duty-cycle use. |
Use Scenario: Programmable logic controllers deployed in factory automation systems where firmware must retain integrity across frequent power cycling and electrical noise. IC Role / Device Role / Timing Role: Read-only firmware repository for real-time control engine; accessed continuously during runtime with 70 ns access enabling deterministic scan times. Use Value: Industrial temperature rating (–40°C to +85°C) and 200 mA latchup immunity ensure reliable operation in electrically harsh cabinet environments. |
| Legacy System Upgrades | Smart Meter Boot Memory |
Use Scenario: Retrofitting aging 5V industrial controllers with low-power replacements while retaining existing PCB layouts and firmware toolchains. IC Role / Device Role / Timing Role: Pin-compatible EPROM substitute for AT27C256R; operates identically in read mode with identical timing and signal levels. Use Value: JEDEC-compliant SOIC footprint and TTL-compatible outputs allow hardware reuse without redesign or requalification. |
Use Scenario: Electricity and gas meters requiring tamper-resistant, long-life firmware storage operating from primary lithium batteries over 10+ year field life. IC Role / Device Role / Timing Role: One-time programmable boot ROM holding secure bootloader and metrology calibration constants. Use Value: OTP structure prevents unauthorized firmware modification; unregulated 2.7–3.6V operation matches primary battery discharge curve without regulation losses. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C256R-70PC | 5V-only operation (4.5–5.5V); no low-voltage mode; same 70 ns access and 28-pin PDIP package. | Lacks battery-voltage support; unsuitable for portable or dual-supply systems. | Select when upgrading legacy 5V-only systems with no battery or low-voltage requirement. |
| AT27LV256A-12JC | 3V-only operation (2.7–3.6V); identical pinout and timing but lacks 5V compatibility and VPP programming pin. | Cannot operate in 5V hosts; requires separate 3V supply rail and dedicated 3V programmers. | Select for new 3V-only designs prioritizing lowest possible active power, accepting loss of 5V interoperability. |
Compared with AT27C256R-70PC and AT27LV256A-12JC, the AT27BV256-12RI uniquely bridges both voltage domains-enabling single-BOM deployment across 3V portable and 5V infrastructure products-while retaining full programming compatibility and industrial temperature qualification.
Availability
AT27BV256-12RI is available at Aetrix Electronics and suitable for industrial control systems, portable medical instrumentation, and smart utility metering requiring stable component supply across extended product lifecycles.
Supply support for AT27BV256-12RI 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 was a leading semiconductor designer specializing in microcontrollers, nonvolatile memory, and wireless solutions before its acquisition by Microchip Technology in 2016.
The AT27BV256-12RI belongs to Atmel's Battery-Voltage™ OTP EPROM family, engineered specifically for energy-constrained embedded systems needing reliable, low-power firmware storage without voltage regulation overhead.
FAQ
What is the maximum operating voltage for AT27BV256-12RI during normal read operation?
The AT27BV256-12RI supports two distinct read-mode supply ranges: 2.7V to 3.6V for low-voltage battery applications and 4.5V to 5.5V for standard 5V systems. It must not be operated outside these ranges during read or standby modes; exceeding 3.6V in the low-voltage range or falling below 4.5V in the 5V range violates specification limits and may cause functional failure. The AT27BV256-12RI does not support intermediate voltages like 4.0V.
Can AT27BV256-12RI be programmed using standard EPROM programmers?
Yes, the AT27BV256-12RI uses the same programming algorithm and equipment as the AT27C256R, including industry-standard programmers that support 100 µs CE pulses and 13.0V VPP. Its integrated product identification code (0x1E/0x8C) ensures automatic recognition by compliant programmers. However, the AT27BV256-12RI requires VPP = 13.0V and VCC = 6.5V during programming-distinct from its read-mode voltages-so the programmer must supply both rails correctly.
Does AT27BV256-12RI support true 3.3V logic interfacing without level shifters?
Yes, the AT27BV256-12RI produces TTL-compatible outputs at VCC = 3.0V, meeting VOH ≥ 2.4V and VOL ≤ 0.4V under 2.0 mA load-fully compatible with 3.3V microcontrollers and FPGAs. Input thresholds scale with VCC (VIH ≥ 0.7×VCC), ensuring reliable recognition of 3.3V logic highs. No level-shifting circuitry is needed when interfacing with 3.3V systems operating within the 2.7–3.6V supply range.
What decoupling capacitors are required for stable operation of AT27BV256-12RI?
The AT27BV256-12RI requires a 0.1 µF ceramic capacitor placed between VCC and GND, mounted as close as possible to the device pins to suppress transient voltage excursions during CE transitions. For systems with multiple AT27BV256-12RI devices or large EPROM arrays, a 4.7 µF bulk electrolytic capacitor should also be added near the power entry point. These values are specified in the Atmel datasheet and are mandatory-not optional-for reliable read and standby operation.
Is AT27BV256-12RI pin-compatible with AT27C256R in all operating modes?
The AT27BV256-12RI is pin-compatible with AT27C256R in read, output disable, and standby modes-including identical pin functions, timing, and signal levels. However, programming differs: AT27BV256-12RI requires VPP = 13.0V, whereas AT27C256R uses VPP = 12.5V. While the pin mapping matches, the higher VPP demand means programmers must be configured for the AT27BV256-12RI's specific voltage profile to avoid incomplete programming.
AT27BV256-12RI 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:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 120 ns
- Voltage - Supply:
- 2.7V ~ 3.6V, 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOIC
AT27BV256-12RI FAQ
1.How can I place an order for AT27BV256-12RI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27BV256-12RI 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 AT27BV256-12RI reliable?
The price and inventory of AT27BV256-12RI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27BV256-12RI is usually 5 days.
3.What payment methods are accepted for AT27BV256-12RI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27BV256-12RI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27BV256-12RI?
AT27BV256-12RI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27BV256-12RI 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 AT27BV256-12RI?
For technical support, including AT27BV256-12RI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27BV256-12RI requirements.
6.How does Aetrix verify that AT27BV256-12RI is sourced from the original manufacturer or authorized distributors?
All AT27BV256-12RI 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 AT27BV256-12RI meets industry standards.
7.What is the process for return or replacement of AT27BV256-12RI?
All AT27BV256-12RI units undergo pre-shipment inspection (PSI). If there is an issue with AT27BV256-12RI, 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 AT27BV256-12RI part is unused and in its original packaging.
Return procedure for AT27BV256-12RI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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