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Microchip Technology AT27BV256-70JU
- Part No.:
- AT27BV256-70JU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT27BV256-70JU.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:192
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Product details
Overview
AT27BV256-70JU from Microchip Technology (formerly Atmel) is a 32K × 8-bit, one-time programmable EPROM with 70 ns read access time, dual-voltage operation (2.7–3.6 V or 4.5–5.5 V), and industrial temperature range (−40°C to +85°C). It serves as a low-power, battery-friendly OTP memory in portable instrumentation, legacy industrial controllers, and embedded boot ROM applications where non-volatility and pin compatibility with AT27C256R are critical.
For engineers reviewing the AT27BV256-70JU datasheet, AT27BV256-70JU pinout, AT27BV256-70JU application, or AT27BV256-70JU equivalent, this page delivers verified technical context, JEDEC-compliant PLCC-32 package details, rapid programming behavior (100 µs/byte), standby current (<1 µA typical at 3V), and TTL/LVBO interface compatibility - all essential for legacy system refresh, battery-powered design, and drop-in replacement validation.
Technical Context
The AT27BV256-70JU implements a CMOS-based OTP EPROM architecture with two-line control (CE/OE), enabling bus contention avoidance in multi-device systems. Its dual-supply capability supports unregulated battery use (2.7–3.6 V) and standard 5 V ±10% operation, while maintaining TTL-level outputs at 3.0 V and LVBO compliance at 2.7 V.
It features integrated product identification (0x1E8C), rapid programming via 100 µs CE pulses at VCC = 6.5 V / VPP = 13.0 V, and robust reliability specs: 2,000 V HBM ESD protection and 200 mA latchup immunity. Programming requires no external high-voltage generator beyond standard EPROM programmers compatible with AT27C256R.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 262,144 bits (32K × 8), fixed OTP configuration - no erase capability; suitable for immutable firmware or calibration data storage. |
| Read access time | 70 ns max at VCC = 2.7–3.6 V or 4.5–5.5 V - enables direct interfacing with 14 MHz microcontrollers without wait states. |
| Supply voltage range | 2.7–3.6 V (unregulated battery) or 4.5–5.5 V (standard logic rail) - eliminates need for LDO regulation in portable designs. |
| Standby current | 20 µA max (CMOS mode), <1 µA typical at 3.0 V - extends battery life in always-on monitoring systems. |
| Active power dissipation | 29 mW max at 5 MHz / VCC = 3.6 V - consumes ~20% of equivalent 5 V EPROMs, reducing thermal load in dense PCB layouts. |
| Input/output compatibility | JEDEC LVTTL and LVBO compliant - interoperates with both 3.3 V microcontrollers and legacy 5 V TTL peripherals without level shifters. |
| Programming speed | 100 µs/byte typical - reduces production programming time vs. older EPROMs; uses same equipment as AT27C256R. |
Pinout & Package
AT27BV256-70JU is housed in a 32-lead plastic J-leaded chip carrier (PLCC-32), JEDEC MS-016 Variation AE compliant, with lead finish matte tin. Pins 1 and 17 are NC (no connect); package dimensions: 12.45 mm × 14.98 mm × 3.35 mm (D × E × A).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address inputs | 15-bit address bus supporting full 32K-word addressing; TTL/LVCMOS-compatible thresholds ensure reliable decoding across supply ranges. |
| O0–O7 | Data outputs | 8-bit bidirectional data bus (output-only during read); VOH/VOL meet TTL spec at VCC ≥ 2.7 V, enabling direct connection to 5 V logic. |
| CE | Chip enable | Active-low primary device select; controls entry into standby mode when high - critical for power gating in multi-EPROM systems. |
| OE | Output enable | Active-low output gate; allows shared bus operation by disabling outputs independently of CE state. |
| VCC | Power supply | Primary supply pin accepting 2.7–3.6 V or 4.5–5.5 V; requires 0.1 µF ceramic decoupling capacitor per device. |
| VPP | Programming voltage | 13.0 V ±0.25 V input during programming only; must be applied simultaneously with VCC and isolated from read-mode operation. |
| GND | Ground reference | Common return path for VCC and VPP; layout requires low-inductance connection to minimize transient noise during CE transitions. |
| NC | No connect | Pins 1, 17, and several internal pads (e.g., A11, A12 positions) are unused - must remain unconnected per JEDEC PLCC-32 footprint. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid programming algorithm | 100 µs/byte typical programming time with automatic verify-reprogram loop - cuts production burn-in time by >5× vs. conventional EPROMs. |
| Dual-voltage read operation | Single device supports both 3 V battery rails and 5 V host systems - eliminates BOM duplication for field-upgradable modules used across platforms. |
| Integrated product ID code | Fixed 16-bit identifier (0x1E8C) accessible via A9/A0 toggling - enables automated programmer recognition and prevents incorrect algorithm selection. |
| Low-power standby mode | <1 µA typical ICC at 3.0 V - enables years-long operation on coin-cell batteries in maintenance-free sensor nodes or tamper-evident loggers. |
| JEDEC PLCC-32 packaging | Industry-standard surface-mount footprint with 1.27 mm pitch - ensures compatibility with legacy reflow profiles and avoids redesign when replacing AT27C256R. |
Applications
| Portable Medical Instrumentation | Industrial PLC Firmware Storage |
|---|---|
|
Use Scenario: Battery-powered handheld blood glucose meters requiring immutable calibration tables and firmware that survive 10+ years without refresh. IC Role / Device Role / Timing Role: OTP EPROM storing factory-trimmed ADC coefficients and boot code; accessed during power-up initialization with 70 ns latency. Use Value: Eliminates need for EEPROM write endurance management or external voltage regulators - reduces BOM cost and increases long-term reliability. |
Use Scenario: DIN-rail mounted programmable logic controllers using fixed ladder logic stored in non-volatile memory, operating continuously in factory environments. IC Role / Device Role / Timing Role: Boot ROM holding startup sequence and safety-critical control routines; read during cold start with guaranteed timing under −40°C to +85°C. Use Value: Industrial temperature rating and 200 mA latchup immunity prevent field failures due to voltage transients on noisy plant-floor power rails. |
| Legacy Embedded System Refresh | Secure Boot Module for FPGA Configuration |
|
Use Scenario: Upgrading aging avionics test equipment where original AT27C256R parts are obsolete but PCB layout cannot be modified. IC Role / Device Role / Timing Role: Pin-compatible OTP replacement providing identical 32K × 8 organization and JEDEC PLCC-32 footprint. Use Value: Enables drop-in replacement without PCB rework or firmware changes - accelerates obsolescence mitigation with zero risk to flight-certified hardware. |
Use Scenario: FPGA-based communication gateway requiring tamper-resistant configuration bitstream storage before SRAM-based FPGA initialization. IC Role / Device Role / Timing Role: Secure, one-time-programmable source of golden configuration image; read once at power-on reset with deterministic 70 ns access. Use Value: Prevents unauthorized modification of FPGA bitstream - unlike flash or EEPROM, OTP memory cannot be rewritten in-system after programming. |
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 | 5 V only operation (4.5–5.5 V); no 2.7–3.6 V support; same 70 ns speed and PLCC-28 package (not pin-compatible with PLCC-32). | Requires board-level voltage regulation; unsuitable for battery-powered systems or mixed-voltage hosts. | Select only if legacy 5 V-only design mandates identical footprint and no low-voltage operation is needed. |
| AT27LV256A-70PU | 3 V operation only (2.7–3.6 V); lacks 5 V compatibility; uses PLCC-32 but has different programming voltage (12.5 V) and slower tACC (90 ns). | Cannot interface directly with 5 V TTL buses without level translation; incompatible with rapid programming algorithms of AT27BV256-70JU. | Choose only when strict 3 V system isolation is required and 5 V host interoperability is unnecessary. |
Compared with AT27C256R-70PU and AT27LV256A-70PU, the AT27BV256-70JU uniquely bridges 3 V and 5 V domains while retaining PLCC-32 mechanical compatibility and rapid programming - making it the sole option for dual-supply legacy upgrades without layout change or voltage translation.
Availability
AT27BV256-70JU is available at Aetrix Electronics and suitable for portable medical instrumentation, industrial PLC firmware storage, legacy embedded system refresh, and secure FPGA boot modules requiring stable component supply across extended product lifecycles.
Supply support for AT27BV256-70JU 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 support for legacy Atmel memory products. The company specializes in microcontrollers, analog, and non-volatile memory solutions for industrial, automotive, and consumer markets.
The AT27BV256-70JU belongs to Atmel's OTP EPROM product line, designed specifically for cost-sensitive, high-reliability applications requiring immutable firmware storage in space-constrained, battery-operated, or harsh-environment systems.
FAQ
What is the maximum operating temperature range for the AT27BV256-70JU?
The AT27BV256-70JU is rated for industrial temperature operation from −40°C to +85°C. This specification is validated per JEDEC standards and applies across both 2.7–3.6 V and 4.5–5.5 V supply conditions. All AC timing parameters, including the 70 ns tACC, are guaranteed within this full range - critical for deployment in factory automation or outdoor telemetry equipment where ambient extremes occur.
Does the AT27BV256-70JU require external high-voltage circuitry for programming?
No, the AT27BV256-70JU does not require custom high-voltage circuitry. It uses standard EPROM programming equipment compatible with the AT27C256R, applying VPP = 13.0 V ±0.25 V and VCC = 6.5 V ±0.25 V during programming. The rapid algorithm (100 µs/byte) and integrated product ID ensure correct algorithm selection - eliminating need for external HV generators or firmware adaptation.
Is the AT27BV256-70JU pin-compatible with the AT27C256R?
The AT27BV256-70JU is functionally pin-compatible with the AT27C256R in terms of signal assignment (A0–A14, O0–O7, CE, OE, VCC, GND, VPP), but uses a 32-lead PLCC (PLCC-32) versus the AT27C256R's 28-lead PLCC (PLCC-28). Therefore, it is not mechanically pin-compatible - PCB layout revision is required to accommodate the larger 32-pin footprint, though signal mapping remains identical.
Can the AT27BV256-70JU operate reliably at 2.7 V supply voltage?
Yes, the AT27BV256-70JU is fully specified down to 2.7 V for read operations. At VCC = 2.7 V, tACC remains ≤70 ns, and standby current is <1 µA typical. Its LVBO compliance ensures stable TTL-level outputs even at minimum supply - enabling direct interface with 2.7 V microcontrollers without level shifters, ideal for single-cell lithium systems.
What decoupling capacitance is required for stable operation of the AT27BV256-70JU?
Each AT27BV256-70JU requires a 0.1 µF high-frequency ceramic capacitor placed between VCC and GND, mounted as close as possible to the device pins. For boards with multiple EPROMs, a 4.7 µF bulk electrolytic capacitor must also be added near the power entry point. These values are mandatory per Atmel's system design guidelines to suppress transients caused by CE switching and ensure datasheet-compliant timing and reliability.
AT27BV256-70JU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Active
- 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:
- 32-PLCC (13.97x11.43)
AT27BV256-70JU FAQ
1.How can I place an order for AT27BV256-70JU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27BV256-70JU 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 AT27BV256-70JU reliable?
The price and inventory of AT27BV256-70JU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27BV256-70JU is usually 5 days.
3.What payment methods are accepted for AT27BV256-70JU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27BV256-70JU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27BV256-70JU?
AT27BV256-70JU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27BV256-70JU 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 AT27BV256-70JU?
For technical support, including AT27BV256-70JU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27BV256-70JU requirements.
6.How does Aetrix verify that AT27BV256-70JU is sourced from the original manufacturer or authorized distributors?
All AT27BV256-70JU 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 AT27BV256-70JU meets industry standards.
7.What is the process for return or replacement of AT27BV256-70JU?
All AT27BV256-70JU units undergo pre-shipment inspection (PSI). If there is an issue with AT27BV256-70JU, 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 AT27BV256-70JU part is unused and in its original packaging.
Return procedure for AT27BV256-70JU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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