My Inquiry
My Account
Microchip Technology AT27BV256-70TU
- Part No.:
- AT27BV256-70TU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
AT27BV256-70TU.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,996
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT27BV256-70TU 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-voltage operation (2.7–3.6V or 4.5–5.5V), and JEDEC-standard 28-pin TSOP packaging. It delivers TTL-compatible outputs at 3.0V and supports LVBO interface compliance at 2.7V, enabling direct integration into portable instrumentation and embedded controllers.
For engineers reviewing the AT27BV256-70TU datasheet, AT27BV256-70TU pinout, AT27BV256-70TU application, or AT27BV256-70TU equivalent, key selection criteria include unregulated battery voltage support, rapid 100 µs/byte programming, 20 µA max standby current at 3.6V, JEDEC-compliant TSOP footprint, and compatibility with standard AT27C256R system designs.
Technical Context
The AT27BV256-70TU implements a CMOS OTP EPROM architecture with two-line control (CE/OE), supporting fast random-access reads and Rapid™ programming via VPP = 13.0V. Its dual-supply capability enables seamless operation across 3V and 5V host environments without level-shifting circuitry.
It features integrated product identification code (Manufacturer ID: 0x1E, Device ID: 0x8C), 2,000V ESD protection, and 200 mA latchup immunity. The device requires external 0.1 µF ceramic decoupling between VCC and GND to suppress transients during CE switching.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 262,144 bits (32K × 8), fixed OTP configuration - no rewrites, ideal for firmware boot code storage |
| Read Access Time | 70 ns max at VCC = 2.7–3.6V - enables real-time execution in 8-bit microcontroller systems |
| Supply Voltage Range | 2.7V–3.6V (unregulated battery) or 4.5V–5.5V - eliminates need for voltage regulation in portable designs |
| Standby Current | 20 µA max at VCC = 3.6V - extends battery life in always-on embedded monitoring devices |
| Programming Speed | 100 µs/byte typical - reduces production programming time versus legacy 5V EPROMs |
| Output Compatibility | TTL-level outputs at VCC = 3.0V; LVBO-compliant at 2.7V - interoperable with mixed-voltage logic families |
| Operating Temperature | -40°C to +85°C - qualified for industrial-grade environmental resilience |
Pinout & Package
AT27BV256-70TU is supplied in a 28-lead plastic thin small outline package (TSOP), JEDEC standard Type 1, 8.1 mm × 13.7 mm body, 0.55 mm pitch. Pin 1 marked by index notch; pins are gull-wing surface-mount terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus - selects one of 32,768 bytes; compatible with Z80, 8051, and 68K family address mapping |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus - drives TTL loads directly at 3.0V VCC without buffer stages |
| CE | Chip Enable | Active-low chip select - controls device activation; transient suppression required on this line per design guidelines |
| OE | Output Enable | Active-low output gate - enables data bus drive only when both CE and OE are asserted |
| VCC | Power Supply | Primary supply input - must be applied before/with VPP during programming; decoupling mandatory |
| GND | Ground Reference | Signal and power return - shared reference for all I/O and internal logic |
| VPP | Programming Voltage | 13.0V ± 0.25V programming supply - isolated from VCC during normal read operation |
| NC | No Connect | Unbonded pins (e.g., A12 in TSOP top view) - must remain floating, not tied to any net |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical - cuts programming time by >5× vs. conventional EPROMs, improving manufacturing throughput |
| Dual-Voltage Read Operation | Supports 2.7–3.6V and 4.5–5.5V supplies - allows single BOM for 3V and 5V system variants |
| Integrated Product ID Code | Manufacturer ID 0x1E / Device ID 0x8C - enables automatic algorithm selection in industry-standard programmers |
| JEDEC Pin Compatibility | Pin-for-pin match with AT27C256R - permits drop-in replacement in existing 28-pin SOIC/TSOP layouts |
| Low-Power CMOS Design | 20 µA max standby at 3.6V - reduces quiescent power in battery-backed memory retention circuits |
Applications
| Portable Data Logger | Industrial PLC Firmware Storage |
|---|---|
Use Scenario: Battery-powered environmental sensor node logging temperature/humidity every 10 seconds with wake-on-interrupt operation. IC Role / Device Role / Timing Role: OTP EPROM storing immutable boot loader and calibration constants; accessed only at power-up and reset. Use Value: Unregulated 2.7–3.6V operation eliminates DC-DC converter, reducing bill-of-materials and PCB area while maintaining 70 ns boot code fetch latency. |
Use Scenario: Fixed-function controller in factory automation cabinet requiring field-upgradeable but tamper-proof firmware image. IC Role / Device Role / Timing Role: Non-volatile program memory holding ladder logic interpreter and I/O configuration tables. Use Value: Industrial temperature range (-40°C to +85°C) and 200 mA latchup immunity ensure reliability in electrically noisy plant-floor environments. |
| Medical Diagnostic Handheld | Legacy System Emulation Module |
Use Scenario: Portable ultrasound probe with embedded DSP requiring certified, unalterable signal processing firmware. IC Role / Device Role / Timing Role: Secure boot ROM verified at power-on; outputs drive 3.3V FPGA configuration bus. Use Value: TTL-compatible outputs at 3.0V VCC enable direct interfacing with FPGA I/O banks without level translators, simplifying layout. |
Use Scenario: Retrofit adapter board emulating discontinued AT27C256R in vintage test equipment using modern PCB fabrication. IC Role / Device Role / Timing Role: Pin-compatible memory replacement preserving original timing margins and socket footprint. Use Value: Identical 28-pin TSOP package and 70 ns tACC allow zero-layout-change upgrade path with full functional equivalence in read mode. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C256R-70PU | 5V-only operation (4.5–5.5V); no 2.7–3.6V support; same 70 ns speed and 28-pin PDIP package | Requires regulated 5V supply; unsuitable for battery-powered systems with unregulated rails | Select when legacy 5V-only systems demand identical form-factor and timing, and battery operation is not required. |
| AT27LV256A-70PU | 3V-only operation (2.7–3.6V); lacks 5V compatibility; uses same Rapid™ programming but no VPP pin - programmed at VCC | Cannot operate in dual-voltage hosts; incompatible with 5V system slots or mixed-voltage backplanes | Select only for new 3V-only designs where 5V interoperability is unnecessary and simplified programming voltage is preferred. |
Compared with AT27C256R-70PU and AT27LV256A-70PU, the AT27BV256-70TU uniquely bridges 3V and 5V domains - enabling single-firmware deployment across portable and desktop platforms - while retaining pin compatibility and programming tooling alignment with both alternatives.
Availability
AT27BV256-70TU is available at Aetrix Electronics and suitable for portable instrumentation, industrial PLC firmware storage, and medical handheld diagnostics requiring stable component supply with long-term lifecycle assurance.
Supply support for AT27BV256-70TU 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 U.S.-based semiconductor designer specializing in microcontrollers, non-volatile memory, and secure authentication ICs before its acquisition by Microchip Technology in 2016.
The AT27BV256-70TU belongs to Atmel's Battery-Voltage™ OTP EPROM product line, engineered specifically for direct integration into unregulated battery-powered systems without external voltage regulation or level translation.
FAQ
What voltage ranges does the AT27BV256-70TU support during normal read operation?
The AT27BV256-70TU supports two distinct read voltage ranges: 2.7V to 3.6V for unregulated battery applications and 4.5V to 5.5V for standard 5V systems. It does not operate reliably outside these bands in read mode, and VCC must be stable within tolerance during access. The AT27BV256-70TU achieves 70 ns access time across both ranges, with TTL-compatible outputs at 3.0V and LVBO compliance at 2.7V.
Is the AT27BV256-70TU pin-compatible with the AT27C256R?
Yes, the AT27BV256-70TU is JEDEC-pin-compatible with the AT27C256R in 28-pin SOIC and TSOP packages, including identical pin functions (A0–A14, O0–O7, CE, OE, VCC, GND, VPP). This allows direct substitution in existing layouts, though AT27BV256-70TU requires VPP = 13.0V for programming while AT27C256R uses 21V - programming equipment must be configured accordingly. The AT27BV256-70TU retains the same product ID code (0x1E/0x8C) for tool compatibility.
What decoupling capacitance is required for stable operation of the AT27BV256-70TU?
The AT27BV256-70TU requires a 0.1 µF high-frequency ceramic capacitor placed between VCC and GND, mounted as close as possible to the device pins. This is mandatory to suppress voltage transients caused by CE switching, which otherwise risk exceeding absolute maximum ratings. For multi-device arrays, a 4.7 µF bulk electrolytic capacitor should also be added near the power entry point. These values are specified in the AT27BV256-70TU datasheet Section "System Considerations" and apply regardless of operating voltage range.
Does the AT27BV256-70TU support programming at 3.3V or 5V?
No - programming the AT27BV256-70TU requires VCC = 6.5V ± 0.25V and VPP = 13.0V ± 0.25V, per the DC Programming Characteristics table. Normal read operation uses only VCC (2.7–3.6V or 4.5–5.5V); VPP is disconnected during read. The AT27BV256-70TU cannot be programmed at 3.3V or 5V. Programming must occur in dedicated equipment capable of delivering precise high-voltage pulses, and VCC must be applied simultaneously with or before VPP.
What is the meaning of "Battery-Voltage™" in the AT27BV256-70TU product name?
"Battery-Voltage™" denotes Atmel's proprietary qualification for operation across the full unregulated lithium or alkaline battery discharge curve (2.7V to 3.6V), eliminating the need for external voltage regulation. The AT27BV256-70TU maintains guaranteed 70 ns access time, TTL-compatible outputs at 3.0V, and sub-20 µA standby current across this range - a capability not found in standard 5V EPROMs or early 3V-only variants. This trademark reflects validated performance under real-world battery conditions, not just nominal voltage points.
AT27BV256-70TU 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:
- 70 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-TSOP
AT27BV256-70TU FAQ
1.How can I place an order for AT27BV256-70TU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27BV256-70TU 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 AT27BV256-70TU reliable?
The price and inventory of AT27BV256-70TU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27BV256-70TU is usually 5 days.
3.What payment methods are accepted for AT27BV256-70TU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27BV256-70TU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27BV256-70TU?
AT27BV256-70TU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27BV256-70TU 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 AT27BV256-70TU?
For technical support, including AT27BV256-70TU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27BV256-70TU requirements.
6.How does Aetrix verify that AT27BV256-70TU is sourced from the original manufacturer or authorized distributors?
All AT27BV256-70TU 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 AT27BV256-70TU meets industry standards.
7.What is the process for return or replacement of AT27BV256-70TU?
All AT27BV256-70TU units undergo pre-shipment inspection (PSI). If there is an issue with AT27BV256-70TU, 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 AT27BV256-70TU part is unused and in its original packaging.
Return procedure for AT27BV256-70TU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT27BV256-70TU Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
