My Inquiry
My Account
Microchip Technology AT28C64E-25JI
- Part No.:
- AT28C64E-25JI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT28C64E-25JI.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,313
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT28C64E-25JI from Atmel is a 64 Kbit (8K × 8) parallel EEPROM with JEDEC-standard byte-wide pinout, 250 ns read access time, 200 µs fast byte write cycle, and industrial temperature range (–40°C to +85°C). It operates from a single 5V ±10% supply, supports READY/BUSY and DATA polling for write completion detection, and is used in firmware storage, configuration memory, and boot code retention in embedded controllers.
For engineers reviewing the AT28C64E-25JI datasheet, AT28C64E-25JI pinout, AT28C64E-25JI application, or AT28C64E-25JI equivalent, key selection criteria include its 100,000-cycle endurance, CMOS standby current of 100 µA, self-timed write architecture, and compatibility with microprocessor buses without external timing logic.
Technical Context
The AT28C64E-25JI implements a self-timed byte write cycle with internal address/data latching and automatic clear-before-write logic. Its RDY/BUSY open-drain output and I/O7 data polling provide two independent methods to detect write completion without bus contention.
It features VCC sense (write inhibit below 3.8 V), 5 ms power-on delay before write enable, and triple-level write protection via CE/OE/WE control states. The device includes 32 bytes of dedicated identification EEPROM accessible at addresses 1FE0H–1FFFH using A9 = 12 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8,192 × 8), directly addressable as static RAM |
| Read Access Time | 250 ns - determines maximum CPU read speed without wait states |
| Byte Write Time | 200 µs - enables full memory rewrite in ≤1.6 seconds |
| Endurance | 100,000 write cycles - supports frequent field updates in industrial firmware |
| Data Retention | 10 years at 85°C - ensures long-term reliability in unpowered storage |
| Supply Voltage | 5 V ±10% - compatible with standard TTL/CMOS logic rails |
| Standby Current | 100 µA (CMOS mode) - enables low-power operation during idle periods |
Pinout & Package
AT28C64E-25JI is packaged in a 32-lead Plastic J-leaded Chip Carrier (PLCC), with pins 1 and 17 designated "DON'T CONNECT" per official pinout. Pin 1 is RDY/BUSY (open-drain) in functional configurations; pin 17 is NC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus for full 8K-word addressing |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface compatible with 8051, Z80, and 68K families |
| CE | Chip Enable | Active-low chip select; disables outputs and reduces current when high |
| OE | Output Enable | Active-low read control; enables data output only when CE is also low |
| WE | Write Enable | Active-low write strobe; initiates self-timed byte write on falling edge |
| RDY/BUSY | Open-Drain Status Output | Pulled low during write; released high when complete - supports wired-OR multi-device status lines |
| VCC, GND | Power Supply | Single 5 V supply; no separate VPP required for write/erase |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed byte write | Eliminates need for external write timing circuitry; frees CPU bus after address/data latch |
| Dual write completion detection | RDY/BUSY signal + I/O7 data polling - provides hardware and software handshaking options |
| VCC-sense write protection | Prevents inadvertent writes during power ramp-up or brownout (disabled below 3.8 V) |
| JEDEC-standard pinout | Drop-in replacement for industry-standard 28-pin EPROM/EEPROM sockets (with PLCC adapter) |
| User-accessible ID memory | 32-byte reserved area (1FE0H–1FFFH) for serialization, calibration, or firmware version tracking |
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 environments. IC Role / Device Role / Timing Role: Nonvolatile configuration register bank accessed via 8-bit parallel bus during boot and runtime parameter updates. Use Value: 100,000-cycle endurance ensures reliable reprogramming over 10+ years of daily maintenance cycles; 250 ns read time avoids CPU wait states in real-time scan cycles. |
Use Scenario: Holding sensor calibration coefficients, device serial numbers, and regulatory compliance flags in portable diagnostic equipment. IC Role / Device Role / Timing Role: Secure, tamper-resistant configuration store with write-protection enforced by VCC sensing and triple-control logic. Use Value: 10-year data retention at 85°C guarantees accuracy across sterilization cycles and extended shelf life; RDY/BUSY signaling prevents data corruption during battery-backed writes. |
| Telecom Line Card Boot Code | Automotive ECU Parameter Tables |
Use Scenario: Storing boot firmware and FPGA configuration bitstreams in carrier-grade line cards requiring hot-swap capability. IC Role / Device Role / Timing Role: Parallel boot ROM mapped into CPU address space; accessed during cold/warm reset sequences. Use Value: 200 µs byte write enables rapid field updates of minor patches without full flash erase; JEDEC pinout simplifies PCB reuse across legacy designs. |
Use Scenario: Retaining adaptive learning values (e.g., fuel trim, idle air control offsets) in engine control units exposed to wide thermal cycling. IC Role / Device Role / Timing Role: High-reliability parameter scratchpad with automatic clear-before-write to prevent partial writes during voltage transients. Use Value: Industrial temperature rating (–40°C to +85°C) and 100 µA standby current support operation in under-hood environments with intermittent power; DATA polling avoids added interrupt latency. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C64B-25JI | Slower write time (1 ms vs. 200 µs); 10K endurance vs. 100K | Lower-cost option where infrequent updates suffice | Select if firmware update frequency is <100×/year and cost sensitivity outweighs speed/reliability needs |
| MN65C6408-25PL | Same 64K × 8 organization, 250 ns access, but requires 12 V VPP for write; no RDY/BUSY pin | Lacks hardware busy signaling; relies solely on polling or fixed delays | Choose only if existing design already uses VPP infrastructure and can tolerate longer, less deterministic write timing |
Compared with AT28C64B-25JI and MN65C6408-25PL, the AT28C64E-25JI delivers superior write speed and endurance without external VPP, making it optimal for systems requiring robust, frequent in-field updates under industrial thermal stress.
Availability
AT28C64E-25JI is available at Aetrix Electronics and suitable for industrial PLC configuration storage, medical device calibration memory, and telecom line card boot code requiring stable component supply, long-lifecycle support, and guaranteed traceable sourcing.
Supply support for AT28C64E-25JI 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.
The AT28C64 family was designed as a drop-in parallel EEPROM replacement for UV-erasable EPROMs and early flash devices, targeting embedded systems needing simple, reliable, single-supply reprogrammable memory with microprocessor bus compatibility.
FAQ
What is the maximum operating temperature range for the AT28C64E-25JI?
The AT28C64E-25JI is rated for industrial temperature operation from –40°C to +85°C. This specification is confirmed in the DC and AC Operating Range table on page 4 of the official datasheet, and applies to all package variants including the 32J PLCC used in AT28C64E-25JI. The device maintains full functionality-including 250 ns read access and 200 µs write-across this entire range.
Does the AT28C64E-25JI require an external 12 V supply for programming?
No, the AT28C64E-25JI operates from a single 5 V ±10% supply for both read and write operations. A 12 V supply is only required for two optional functions: CHIP CLEAR (applied to OE) and accessing the 32-byte device identification memory (applied to A9). These are not needed for standard byte write or read operations, and the AT28C64E-25JI performs all normal writes autonomously at 5 V.
How does write protection work on the AT28C64E-25JI?
The AT28C64E-25JI implements three independent write protection mechanisms: (1) VCC sense - write is inhibited if VCC falls below ~3.8 V; (2) Power-on delay - a built-in 5 ms timer prevents writes until VCC stabilizes; and (3) Control-line enforcement - write cycles are blocked unless CE is low, OE is high, and WE transitions low. All three must be satisfied for a write to initiate.
Can the AT28C64E-25JI be used as a direct replacement for the AT28C64-25JI?
Yes, the AT28C64E-25JI is a functional and pin-compatible upgrade to the AT28C64-25JI. Both share identical pinout, timing, and electrical specifications, but the "E" variant offers enhanced endurance (100,000 vs. 10,000 cycles) and faster write time (200 µs vs. 1 ms). No PCB or firmware changes are required to migrate from AT28C64-25JI to AT28C64E-25JI.
What is the purpose of the RDY/BUSY pin on the AT28C64E-25JI?
The RDY/BUSY pin (Pin 1) on the AT28C64E-25JI is an open-drain output that actively pulls low during a byte write cycle and releases high upon completion. It enables hardware handshaking with the host microprocessor, allowing the system to pause other bus activity until the write finishes. This eliminates the need for fixed delays or polling loops, improving system efficiency and determinism in time-critical applications.
AT28C64E-25JI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tube
- 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:
- 200µs
- Access Time:
- 250 ns
- Voltage - Supply:
- 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)
AT28C64E-25JI FAQ
1.How can I place an order for AT28C64E-25JI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28C64E-25JI 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 AT28C64E-25JI reliable?
The price and inventory of AT28C64E-25JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28C64E-25JI is usually 5 days.
3.What payment methods are accepted for AT28C64E-25JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28C64E-25JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28C64E-25JI?
AT28C64E-25JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28C64E-25JI 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 AT28C64E-25JI?
For technical support, including AT28C64E-25JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28C64E-25JI requirements.
6.How does Aetrix verify that AT28C64E-25JI is sourced from the original manufacturer or authorized distributors?
All AT28C64E-25JI 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 AT28C64E-25JI meets industry standards.
7.What is the process for return or replacement of AT28C64E-25JI?
All AT28C64E-25JI units undergo pre-shipment inspection (PSI). If there is an issue with AT28C64E-25JI, 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 AT28C64E-25JI part is unused and in its original packaging.
Return procedure for AT28C64E-25JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28C64E-25JI 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…
