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Microchip Technology AT27BV256-12TC
- Part No.:
- AT27BV256-12TC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
AT27BV256-12TC.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,819
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Product details
Overview
AT27BV256-12TC 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 (2.7V–3.6V or 4.5V–5.5V), and 20 µA max standby current at VCC = 3.6V. It serves as nonvolatile program storage in portable instrumentation and embedded controllers requiring unregulated battery voltage tolerance.
For engineers reviewing the AT27BV256-12TC datasheet, AT27BV256-12TC pinout, AT27BV256-12TC application, or AT27BV256-12TC equivalent, key selection criteria include its JEDEC-standard TSOP-28 package, Rapid™ programming algorithm (100 µs/byte), TTL/LVBO interface compatibility, and pin compatibility with AT27C256R for legacy design migration.
Technical Context
The AT27BV256-12TC implements a CMOS OTP EPROM architecture with two-line control (CE/OE), enabling bus contention avoidance in shared-memory systems. Its dual-voltage capability supports both 3.0V TTL-level outputs and 2.7V LVBO-compliant signaling without level-shifting circuitry.
Programming requires VCC = 6.5V and VPP = 13.0V with a 100 µs CE pulse width per byte, verified via integrated product identification code (Manufacturer ID = 0x1E, Device ID = 0x8C). The device uses standard 5V programming equipment and shares identical programming algorithms with AT27C256R and AT27LV256A.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32K × 8) - provides sufficient boot code or firmware storage for mid-complexity microcontroller systems |
| Read Access Time | 70 ns - enables direct execution from memory in 5 MHz–10 MHz CPU systems without wait states |
| Supply Voltage Range | 2.7V–3.6V or 4.5V–5.5V - eliminates need for regulated 5V supply in battery-operated designs |
| Standby Current | 20 µA max at 3.6V - extends battery life in always-on portable devices beyond 1 year on typical coin cells |
| Operating Temperature | -40°C to +85°C - qualified for industrial-grade embedded applications including automotive body control modules |
| Package | 28-Lead TSOP (Type 1) - surface-mount compatible with high-density PCB layouts and automated assembly |
| ESD Protection | 2,000V HBM - meets IEC 61000-4-2 Level 2 requirements for handheld device integration |
Pinout & Package
AT27BV256-12TC is housed in a 28-lead plastic thin small outline package (TSOP) with 0.55 mm pitch and 11.7 mm × 7.9 mm footprint. Pin 1 is marked by a notch or index area on the top surface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word addressing; driven by microcontroller address lines A0–A14 |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus; TTL-compatible outputs drive standard logic loads directly at 3.0V VCC |
| CE | Chip Enable | Active-low chip select; controls device activation and power state transition between active and standby modes |
| OE | Output Enable | Active-low output gate; isolates data bus during read cycles to prevent contention with other peripherals |
| VCC | Power Supply | Primary supply input; accepts 2.7V–3.6V or 4.5V–5.5V; requires 0.1 µF ceramic decoupling capacitor |
| GND | Ground Reference | Signal and power return path; must be connected to system ground plane with minimal impedance |
| VPP | Programming Voltage | 13.0V programming supply input; only active during programming; requires dedicated 0.1 µF VPP-to-GND capacitor |
| NC | No Connect | Pins 1, 17 (PLCC) are unconnected; not present in TSOP-28 package - no routing or termination required |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time reduces firmware update cycle duration by >80% vs. conventional EPROMs |
| Dual-Voltage Read Operation | Supports unregulated battery inputs down to 2.7V while maintaining TTL-compatible outputs - removes need for DC-DC regulation |
| JEDEC Pin Compatibility | Direct replacement for AT27C256R in existing 28-pin SOIC/PLCC layouts - enables drop-in upgrade to low-voltage operation |
| Integrated Product ID Code | Manufacturer ID (0x1E) and Device ID (0x8C) enable automatic algorithm selection in universal programmers - eliminates manual configuration errors |
| Low-Power Standby Mode | Typical 1 µA standby current at 3.0V allows continuous memory retention in energy-harvesting or wake-on-interrupt systems |
Applications
| Portable Medical Instrumentation | Industrial PLC Firmware Storage |
|---|---|
Use Scenario: Handheld blood glucose meters and portable ECG monitors powered by single-cell lithium batteries. IC Role / Device Role / Timing Role: Nonvolatile program memory storing calibration routines and sensor driver firmware; accessed during cold start and periodic self-test. Use Value: Unregulated 2.7V–3.6V operation eliminates buck converter, reducing BOM cost and board space while extending battery runtime by 30% over 5V EPROM solutions. |
Use Scenario: DIN-rail mounted programmable logic controllers deployed in factory automation environments. IC Role / Device Role / Timing Role: Boot ROM holding bootloader and real-time OS kernel; read at power-up and during firmware recovery sequences. Use Value: -40°C to +85°C temperature rating ensures reliable operation in unconditioned control cabinets; 2,000V ESD protection withstands industrial EMI exposure. |
| Legacy System Upgrade Path | Smart Sensor Node Memory |
Use Scenario: Retrofitting aging test equipment originally designed with AT27C256R EPROMs. IC Role / Device Role / Timing Role: Pin-compatible OTP replacement preserving existing PCB layout and programming infrastructure. Use Value: Identical programming algorithm and JEDEC pinout allow reuse of existing UV erasers, programmers, and firmware tools - zero requalification effort. |
Use Scenario: Wireless environmental sensors using intermittent duty cycling to conserve energy. IC Role / Device Role / Timing Role: Persistent storage for sensor calibration coefficients and network stack parameters; retained across deep-sleep cycles. Use Value: 20 µA max standby current enables multi-year operation on CR2032 batteries; rapid programming supports field firmware updates via low-power debug interfaces. |
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 (4.5V–5.5V); no low-voltage mode; 70 ns access; PLCC-32 package | Requires regulated 5V supply; incompatible with battery-powered systems below 4.5V | Select when upgrading legacy 5V-only systems where VCC regulation is already present and low-voltage operation is unnecessary |
| AT27LV256A-12JC | 3.3V-only operation (2.7V–3.6V); same 70 ns speed; PLCC-32 package; identical programming algorithm | Lacks 5V compatibility; cannot operate in dual-supply host systems or mixed-voltage backplanes | Select when designing new 3.3V-native systems with PLCC footprint constraints and no requirement for 5V interoperability |
Compared with AT27C256R-70PC and AT27LV256A-12JC, the AT27BV256-12TC uniquely bridges both voltage domains - enabling single-BOM support across 3V and 5V host platforms while retaining pin and programming compatibility with both families.
Availability
AT27BV256-12TC is available at Aetrix Electronics and suitable for portable medical instrumentation, industrial PLC firmware storage, legacy system upgrades, and smart sensor node memory requiring stable component supply and long-term lifecycle assurance.
Supply support for AT27BV256-12TC 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
Atmel Corporation (now part of Microchip Technology) is a semiconductor manufacturer specializing in microcontrollers, nonvolatile memory, and secure authentication ICs for industrial, automotive, and consumer applications.
The AT27BV256 product line was engineered to deliver battery-voltage-tolerant OTP EPROM functionality for portable and mixed-supply embedded systems, addressing the need for low-power, pin-compatible alternatives to legacy 5V EPROMs.
FAQ
What voltage ranges does the AT27BV256-12TC support during normal read operation?
The AT27BV256-12TC supports two distinct read voltage ranges: 2.7V to 3.6V for unregulated battery operation and 4.5V to 5.5V for standard 5V systems. It does not operate reliably between 3.6V and 4.5V. Both ranges deliver full 70 ns access time and TTL-compatible outputs, making the AT27BV256-12TC suitable for dual-supply host environments such as PCMCIA cards or modular instrumentation.
Is the AT27BV256-12TC pin-compatible with the AT27C256R, and what does that mean for PCB layout?
Yes, the AT27BV256-12TC is JEDEC-pin-compatible with the AT27C256R in matching packages - specifically, the TSOP-28 variant maps identically to the AT27C256R's SOIC-28 pinout. This means no PCB redesign is needed when replacing AT27C256R in existing 28-pin footprints. However, the AT27BV256-12TC requires different decoupling (0.1 µF VCC–GND) and lacks UV-erasability, so firmware update workflows must shift to one-time programming.
What programming voltage and equipment are required for the AT27BV256-12TC?
The AT27BV256-12TC requires VCC = 6.5V ± 0.25V and VPP = 13.0V ± 0.25V during programming, with a 100 µs CE pulse width per byte. It uses the same programming algorithms and equipment as the AT27C256R, including industry-standard EPROM programmers with VPP switching capability. A 0.1 µF capacitor must be placed between VPP and GND during programming to suppress transients, as specified in the AT27BV256-12TC datasheet.
Does the AT27BV256-12TC support identification codes, and how are they accessed?
Yes, the AT27BV256-12TC features an integrated product identification code: Manufacturer ID = 0x1E and Device ID = 0x8C. These are accessed by setting A9 = 12.0V (VH), A0 = VIH or VIL (to select Manufacturer or Device byte), and all other address lines A1–A14 = VIL, with CE = VIL and OE = VIL. This allows automatic device recognition in universal programmers, ensuring correct algorithm and voltage selection for the AT27BV256-12TC.
What is the maximum operating temperature range certified for the AT27BV256-12TC?
The AT27BV256-12TC is rated for industrial temperature operation from -40°C to +85°C, as confirmed by its ordering code suffix "I" variants (e.g., AT27BV256-12TI). The "TC" suffix denotes the TSOP-28 package but does not restrict temperature grade - the commercial (0°C to +70°C) and industrial (-40°C to +85°C) versions share identical electrical specifications except for thermal qualification testing. Always verify the full part number's temperature grade before deployment in extended-temperature environments.
AT27BV256-12TC 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:
- 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:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSOP
AT27BV256-12TC FAQ
1.How can I place an order for AT27BV256-12TC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27BV256-12TC 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 AT27BV256-12TC reliable?
The price and inventory of AT27BV256-12TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27BV256-12TC is usually 5 days.
3.What payment methods are accepted for AT27BV256-12TC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27BV256-12TC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27BV256-12TC?
AT27BV256-12TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27BV256-12TC 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 AT27BV256-12TC?
For technical support, including AT27BV256-12TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27BV256-12TC requirements.
6.How does Aetrix verify that AT27BV256-12TC is sourced from the original manufacturer or authorized distributors?
All AT27BV256-12TC 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 AT27BV256-12TC meets industry standards.
7.What is the process for return or replacement of AT27BV256-12TC?
All AT27BV256-12TC units undergo pre-shipment inspection (PSI). If there is an issue with AT27BV256-12TC, 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 AT27BV256-12TC part is unused and in its original packaging.
Return procedure for AT27BV256-12TC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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