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Microchip Technology AT28HC64B-70TU
- Part No.:
- AT28HC64B-70TU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
AT28HC64B-70TU.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,304
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Product details
Overview
AT28HC64B-70TU from Atmel is a 64 Kbit (8K × 8) parallel EEPROM with JEDEC-standard byte-wide pinout, 70 ns read access time, hardware/software data protection, and page write capability supporting up to 64-byte writes in ≤10 ms. It operates from a single 5 V ±10% supply and targets firmware storage, configuration memory, and calibration data retention in industrial control systems.
For engineers reviewing the AT28HC64B-70TU datasheet, AT28HC64B-70TU pinout, AT28HC64B-70TU application, or AT28HC64B-70TU equivalent, key selection criteria include verified 70 ns read timing, CMOS/TTL-compatible I/O, industrial temperature range (–40°C to +85°C), page write endurance (100,000 cycles), and green (Pb/halide-free) TSOP packaging.
Technical Context
The AT28HC64B-70TU implements a parallel interface with dual-line chip enable (CE) and output enable (OE) control for bus contention avoidance, and supports both byte and page write modes using internal address/data latching. Its write cycle completion is detectable via DATA polling on I/O7 or toggle-bit behavior on I/O6.
Hardware data protection includes VCC sense (<3.8 V inhibit), 5 ms power-on delay, noise filtering on WE/CE (<15 ns rejection), and write-inhibit logic (OE low, CE high, or WE high). Software Data Protection (SDP) is user-configurable via a 3-byte command sequence to addresses 1555H/0AAAH/1555H.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8,192 × 8), organized as byte-addressable nonvolatile storage |
| Read Access Time | 70 ns maximum - enables direct replacement of SRAM in legacy 5 MHz bus systems |
| Page Write Cycle | ≤10 ms maximum - allows burst programming of up to 64 bytes without external timing control |
| VCC Supply | 5 V ±10% - compatible with standard TTL/CMOS logic rails and eliminates need for auxiliary voltage regulators |
| Standby Current | 100 µA CMOS - reduces system power budget during idle states in battery-backed applications |
| Endurance | 100,000 write/erase cycles - supports field-updatable calibration tables with multi-year service life |
| Data Retention | 10 years at 85°C - ensures long-term integrity of stored parameters in unpowered industrial environments |
Pinout & Package
AT28HC64B-70TU is packaged in a 28-lead Thin Small Outline Package (TSOP, Type I, 8 × 13.4 mm), RoHS-compliant and Pb/halide-free per ordering code suffix "TU".
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus selecting one of 8,192 byte locations; A6–A12 define page boundaries for 64-byte writes |
| I/O0–I/O7 | Bidirectional Data Bus | Byte-wide parallel interface; I/O7 provides DATA polling feedback, I/O6 delivers toggle-bit write status |
| CE | Chip Enable | Active-low device select; must be low with OE low and WE high for read access |
| OE | Output Enable | Active-low output gate; controls tri-state buffer to prevent bus contention during shared-memory operation |
| WE | Write Enable | Active-low write strobe; initiates byte or page write when CE is low and OE is high |
| VCC | Power Supply | +5 V ±10% main supply; powers core logic and I/O buffers |
| GND | Ground Reference | Signal and power return path; decoupling required within 10 mm of VCC pin |
| NC | No Connect | Unbonded pins (positions 1, 14, 27, 28 in TSOP top view); must remain floating |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC Byte-wide Pinout | Ensures drop-in compatibility with legacy SRAM and EPROM sockets in existing PCB layouts |
| Internal 64-byte Page Register | Eliminates need for external address/data latches during multi-byte writes, reducing BOM count |
| DATA Polling & Toggle Bit | Provides two independent, hardware-verified methods to detect write completion without timer overhead |
| Software Data Protection (SDP) | Allows selective lock/unlock of entire memory array via 3-byte command sequence, preventing accidental firmware corruption |
| Extra 64-byte ID Area | Dedicated memory block (1FC0H–1FFFH) accessible at 12 V on A9 for unique device serialization or calibration metadata |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Memory |
|---|---|
Use Scenario: Storing I/O mapping, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Nonvolatile configuration register accessed via parallel bus during boot and runtime reconfiguration. Use Value: 100,000-cycle endurance and 10-year data retention ensure parameter integrity across decades of maintenance-free operation in harsh thermal environments. | Use Scenario: Holding sensor offset/gain coefficients and regulatory compliance logs in portable diagnostic equipment requiring traceable calibration history. IC Role / Device Role / Timing Role: Secure, software-protected memory block used during device power-up and periodic self-test sequences. Use Value: SDP-enabled write locking prevents unauthorized modification of calibration data, while 70 ns read speed supports real-time correction during signal acquisition. |
| Telecom Base Station Bootloader Storage | Automotive Body Control Module Settings |
Use Scenario: Hosting bootloader firmware and fail-safe recovery images in outdoor wireless infrastructure units operating across –40°C to +85°C ambient ranges. IC Role / Device Role / Timing Role: Parallel-boot memory mapped into CPU address space; accessed during cold start before DRAM initialization. Use Value: Single 5 V supply simplifies power architecture, and industrial temperature rating guarantees reliable boot execution under extreme environmental stress. | Use Scenario: Retaining seat/mirror position presets, lighting profiles, and CAN node configuration in vehicle body control units subject to repeated power cycling. IC Role / Device Role / Timing Role: Low-power standby memory retaining user preferences during ignition-off periods. Use Value: 100 µA CMOS standby current minimizes battery drain over extended parking durations without compromising write reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ST M28W640ECB90N6 | 64 Mbit (8M × 8), 90 ns access, 3.3 V core with 5 V tolerant I/O, no page write mode | Higher density but slower read; lacks page write and SDP - suited for static firmware storage only | Select when migrating to 3.3 V systems and density >64 Kbit is required; not pin-compatible |
| Microchip 28C64B-25/J | 64 Kbit, 250 ns access, 5 V only, no software protection, no DATA polling, SOIC-28 package | Lower performance and fewer features; suitable only for cost-sensitive, non-critical legacy designs | Choose only if 70 ns timing and advanced write verification are unnecessary; pinout differs in NC placement |
Compared with ST M28W640ECB90N6 and Microchip 28C64B-25/J, the AT28HC64B-70TU uniquely balances fast 70 ns reads, robust 100,000-cycle endurance, and dual hardware/software write protection - making it optimal for industrial systems demanding both speed and data integrity assurance.
Availability
AT28HC64B-70TU is available at Aetrix Electronics and suitable for industrial PLCs, medical calibration systems, and telecom base station bootloaders requiring stable component supply, long-lifecycle support, and green packaging compliance.
Supply support for AT28HC64B-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 (now part of Microchip Technology) is a fabless semiconductor company specializing in microcontrollers, nonvolatile memory, and secure authentication ICs.
The AT28HC64B product line was designed for high-reliability, byte-erasable parallel EEPROM applications in industrial, telecom, and medical equipment where firmware update safety and long-term data retention are critical.
FAQ
What is the guaranteed read access time for AT28HC64B-70TU?
The AT28HC64B-70TU guarantees a maximum read access time of 70 ns under industrial temperature conditions (–40°C to +85°C) and 5 V ±10% supply. This specification is validated per AC Read Characteristics table in the official Atmel datasheet (0274L–PEEPR), enabling direct substitution for 55–70 ns SRAM in legacy bus architectures without timing redesign.
Does AT28HC64B-70TU support page write operations, and what is the maximum page size?
Yes, the AT28HC64B-70TU supports page write operations with a fixed page size of 64 bytes. The device uses an internal 64-byte latch to accept sequential data within a 150 µs window (tBLC), completing the full page write in ≤10 ms. All addresses in a given page write must share identical A6–A12 bits, while A0–A5 select individual bytes within that page.
How does hardware data protection work on AT28HC64B-70TU?
AT28HC64B-70TU implements four hardware safeguards: (1) VCC sense inhibits writes below ~3.8 V; (2) 5 ms power-on delay prevents early writes; (3) write inhibition occurs if OE is low, CE is high, or WE is high; and (4) input noise filtering rejects pulses <15 ns on WE/CE. These mechanisms collectively prevent spurious writes during power transitions or EMI events.
Can AT28HC64B-70TU be used in systems requiring 3.3 V logic levels?
No - the AT28HC64B-70TU requires a single 5 V ±10% supply and features CMOS/TTL-compatible inputs/outputs referenced to that 5 V rail. It is not 3.3 V tolerant; interfacing with 3.3 V microcontrollers requires level-shifting circuitry on all address, data, and control lines to avoid damage or unreliable operation.
What is the purpose of the extra 64-byte memory area in AT28HC64B-70TU?
The AT28HC64B-70TU includes an additional 64-byte EEPROM segment (addresses 1FC0H–1FFFH) accessible only when A9 is raised to 12.0 V ±0.5 V. This area is intended for permanent device identification, manufacturing traceability, or calibration metadata storage - physically isolated from main memory to prevent accidental overwrite during normal operation.
AT28HC64B-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:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 64Kbit
- Memory Organization:
- 8K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 10ms
- Access Time:
- 70 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSOP
AT28HC64B-70TU FAQ
1.How can I place an order for AT28HC64B-70TU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC64B-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 AT28HC64B-70TU reliable?
The price and inventory of AT28HC64B-70TU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28HC64B-70TU is usually 5 days.
3.What payment methods are accepted for AT28HC64B-70TU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC64B-70TU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC64B-70TU?
AT28HC64B-70TU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC64B-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 AT28HC64B-70TU?
For technical support, including AT28HC64B-70TU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC64B-70TU requirements.
6.How does Aetrix verify that AT28HC64B-70TU is sourced from the original manufacturer or authorized distributors?
All AT28HC64B-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 AT28HC64B-70TU meets industry standards.
7.What is the process for return or replacement of AT28HC64B-70TU?
All AT28HC64B-70TU units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC64B-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 AT28HC64B-70TU part is unused and in its original packaging.
Return procedure for AT28HC64B-70TU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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