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Microchip Technology AT27BV256-90TC
- Part No.:
- AT27BV256-90TC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
AT27BV256-90TC.pdf
- Description:
- IC EPROM 256KBIT PARALLEL 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,676
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Product details
Overview
AT27BV256-90TC from Atmel is a 256K-bit (32K × 8) one-time programmable EPROM optimized for low-voltage portable systems, featuring 90 ns read access time, dual-voltage operation (2.7–3.6V or 4.5–5.5V), and JEDEC-standard 28-lead TSOP packaging. It serves as nonvolatile program storage in battery-powered embedded controllers and legacy microprocessor systems requiring pin compatibility with AT27C256R.
For engineers reviewing the AT27BV256-90TC datasheet, AT27BV256-90TC pinout, AT27BV256-90TC application, or AT27BV256-90TC equivalent, key selection criteria include its unregulated battery-voltage support, rapid 100 µs/byte programming, TTL/LVBO interface compatibility, and industrial temperature range (-40°C to +85°C) in TSOP package.
Technical Context
The AT27BV256-90TC implements a CMOS OTP EPROM architecture with two-line control (CE/OE), enabling bus contention avoidance in shared-memory systems. Its dual-supply capability allows direct interfacing with both 3.3V logic and 5V TTL without level shifters, while maintaining <1 µA typical standby current at 3V.
It uses Atmel's Rapid™ Programming Algorithm with 100 µs CE pulses and integrated product identification code (Manufacturer ID: 1Eh, Device ID: 8Ch) for automated programmer recognition. Programming requires VCC = 6.5V and VPP = 13.0V, with strict sequencing (VCC applied before/with VPP).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256 Kbit (32K × 8) - supports full 8-bit data bus interface without multiplexing |
| Read Access Time | 90 ns max at VCC = 2.7–3.6V - meets timing for 11 MHz CPU bus cycles |
| Supply Voltage Range | 2.7V–3.6V or 4.5V–5.5V - eliminates need for voltage regulation in battery-powered designs |
| Standby Current | 20 µA max (CMOS mode) - extends battery life in sleep-mode portable equipment |
| Programming Speed | 100 µs/byte typical - reduces production programming time vs. standard 5V EPROMs |
| Operating Temperature | -40°C to +85°C - qualified for industrial-grade embedded applications |
| Package | 28-lead TSOP (Type 1) - surface-mount compatible with high-density PCB layouts |
Pinout & Package
AT27BV256-90TC is housed in a 28-lead plastic thin small outline package (TSOP), Type 1, compliant with JEDEC MO-153. Pin pitch is 0.5 mm, body width 7.62 mm, and total length 17.9 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word addressing; TTL/LVBO compatible |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus outputs; VOH ≥ VCC − 0.1V at 20 µA ensures robust TTL-level drive |
| CE | Chip Enable | Active-low chip select; controls device activation and power state transitions |
| OE | Output Enable | Active-low output gate; enables data output without affecting internal state |
| VCC | Power Supply | Primary supply input for read/standby modes; accepts 2.7–3.6V or 4.5–5.5V |
| VPP | Programming Voltage | 13.0V ± 0.25V input required only during programming; must be sequenced with VCC |
| GND | Ground Reference | Signal and power ground; requires 0.1 µF ceramic decoupling capacitor per device |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time with automatic verify/reprogram loop up to 10 pulses per byte |
| Dual-Voltage Read Operation | Operates natively at 2.7–3.6V (LVBO) or 4.5–5.5V (TTL), eliminating external regulators in mixed-voltage systems |
| Integrated Product ID Code | Manufacturer ID (1Eh) and Device ID (8Ch) accessible via A9/VH and A0 toggle - enables auto-detection by industry-standard programmers |
| High-Reliability Process | 2000V HBM ESD protection and 200 mA latchup immunity - suitable for manufacturing and field environments |
| JEDEC Pin Compatibility | Pin-for-pin compatible with AT27C256R - allows drop-in replacement in existing 5V designs with no layout change |
Applications
| Industrial Control Firmware Storage | Portable Medical Device Boot ROM |
|---|---|
Use Scenario: Storing firmware for PLC I/O modules operating in harsh factory environments with wide ambient temperature swings. IC Role / Device Role / Timing Role: Nonvolatile boot memory providing deterministic 90 ns read access to initialize real-time control logic on power-up. Use Value: Industrial temperature rating (-40°C to +85°C) and 200 mA latchup immunity ensure reliable operation under electrical noise and thermal stress. | Use Scenario: Holding calibration and safety-critical startup code in handheld glucose meters powered by single-cell lithium batteries. IC Role / Device Role / Timing Role: Low-voltage OTP EPROM delivering stable 3.3V-compatible read access without regulation overhead. Use Value: 2.7–3.6V native operation and <1 µA typical standby current maximize battery runtime between charges. |
| Legacy Microprocessor System Upgrade | Embedded Test Equipment Configuration Memory |
Use Scenario: Replacing obsolete 5V EPROMs in aging 80C88-based test fixtures while retaining existing PCB layout. IC Role / Device Role / Timing Role: Pin-compatible drop-in replacement for AT27C256R with identical SOIC/TSOP footprint and control signaling. Use Value: JEDEC-compliant pinout and TTL-level outputs at 5V allow seamless integration without redesign or signal conditioning. | Use Scenario: Storing instrument-specific calibration constants and self-test routines in benchtop oscilloscopes with modular firmware. IC Role / Device Role / Timing Role: One-time programmable configuration store accessed during power-on initialization sequence. Use Value: Rapid 100 µs/byte programming enables efficient factory calibration and traceable device serialization via ID code. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C256R-90PC | 5V-only operation (4.5–5.5V); no low-voltage mode; same 90 ns speed and 28-pin PDIP package | Limited to regulated 5V systems; unsuitable for battery-powered or dual-supply designs | Select when legacy 5V board space and through-hole assembly are required |
| AT27LV256A-90JC | 3V-only operation (2.7–3.6V); PLCC-32 package; identical Rapid™ programming and ID code | Requires PLCC socket or rework; lacks 5V compatibility for mixed-host environments | Select when PLCC form factor and pure 3V design are prioritized over TSOP density |
Compared with AT27C256R-90PC and AT27LV256A-90JC, the AT27BV256-90TC uniquely supports both 3V and 5V hosts in the compact 28-lead TSOP, making it the only option for space-constrained, dual-voltage portable upgrades.
Availability
AT27BV256-90TC is available at Aetrix Electronics and suitable for industrial control firmware storage, portable medical device boot ROM, and legacy microprocessor system upgrades requiring stable component supply across extended lifecycle demands.
Supply support for AT27BV256-90TC 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 fabless semiconductor company specializing in microcontrollers, nonvolatile memory, and secure authentication ICs.
The AT27BV256 product line was designed for low-power, battery-operated embedded systems requiring reliable OTP storage with flexible voltage operation and rapid programming-targeting portable instrumentation, industrial controllers, and legacy system modernization.
FAQ
What is the maximum read access time specified for AT27BV256-90TC?
The AT27BV256-90TC has a maximum read access time of 90 ns when operated at VCC = 2.7–3.6V or 4.5–5.5V, as confirmed in the AC Characteristics table under the -90 speed grade. This value applies to tACC (address-to-output delay) and tCE (CE-to-output delay) under standard load conditions (CL = 100 pF). The -90 suffix directly denotes this 90 ns timing specification.
Does AT27BV256-90TC require a separate programming voltage supply?
Yes, AT27BV256-90TC requires VPP = 13.0V ± 0.25V during programming, applied to the dedicated VPP pin. VCC must also be raised to 6.5V ± 0.25V, and VCC must be applied simultaneously with or before VPP. During normal read/standby operation, only VCC (2.7–3.6V or 4.5–5.5V) is used; VPP is disconnected or grounded.
Is AT27BV256-90TC pin-compatible with AT27C256R?
Yes, AT27BV256-90TC is explicitly pin-compatible with JEDEC-standard AT27C256R, as stated in the Features section and confirmed by identical pin functions (A0–A14, O0–O7, CE, OE, VCC, GND, VPP) and matching 28-lead TSOP pinout. This allows direct replacement in existing AT27C256R designs without PCB modification.
What is the standby current consumption of AT27BV256-90TC at 3.3V?
At VCC = 3.6V and CMOS-mode standby (CE = VCC ± 0.3V), AT27BV256-90TC draws a maximum of 20 µA, with typical consumption less than 1 µA. This ultra-low standby current is critical for extending battery life in portable applications where the device spends extended periods in inactive state.
Can AT27BV256-90TC operate reliably at 2.7V supply voltage?
Yes, AT27BV256-90TC is fully specified for operation across 2.7V to 3.6V in read mode, including guaranteed 90 ns access time and valid VIH/VIL thresholds. Its "Unregulated Battery-Voltage™" design ensures stable functionality even as battery voltage declines, eliminating the need for voltage regulation in single-cell lithium or alkaline systems.
AT27BV256-90TC 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:
- 90 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
AT27BV256-90TC FAQ
1.How can I place an order for AT27BV256-90TC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27BV256-90TC 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 AT27BV256-90TC reliable?
The price and inventory of AT27BV256-90TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27BV256-90TC is usually 5 days.
3.What payment methods are accepted for AT27BV256-90TC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27BV256-90TC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27BV256-90TC?
AT27BV256-90TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27BV256-90TC 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 AT27BV256-90TC?
For technical support, including AT27BV256-90TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27BV256-90TC requirements.
6.How does Aetrix verify that AT27BV256-90TC is sourced from the original manufacturer or authorized distributors?
All AT27BV256-90TC 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 AT27BV256-90TC meets industry standards.
7.What is the process for return or replacement of AT27BV256-90TC?
All AT27BV256-90TC units undergo pre-shipment inspection (PSI). If there is an issue with AT27BV256-90TC, 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 AT27BV256-90TC part is unused and in its original packaging.
Return procedure for AT27BV256-90TC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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