My Inquiry
My Account
Microchip Technology AT28HC64B-70PI
- Part No.:
- AT28HC64B-70PI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-DIP (0.600", 15.24mm)
- Datasheet:
-
AT28HC64B-70PI.pdf
- Description:
- IC EEPROM 64KBIT PARALLEL 28DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,473
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT28HC64B-70PI from Atmel is a 64 Kbit (8K × 8) parallel EEPROM with JEDEC-standard byte-wide pinout, 70 ns read access time, single 5 V ±10% supply, and industrial temperature range (–40°C to +85°C). It supports hardware/software data protection, DATA polling and toggle-bit write completion detection, and 1–64-byte page writes for embedded system configuration storage.
For engineers reviewing the AT28HC64B-70PI datasheet, AT28HC64B-70PI pinout, AT28HC64B-70PI application, or AT28HC64B-70PI equivalent, key selection criteria include verified 70 ns read timing, CMOS/TTL-compatible I/O, 100 µA standby current, page-write endurance (100,000 cycles), and PDIP-28 packaging for through-hole prototyping and legacy industrial control systems.
Technical Context
The AT28HC64B-70PI implements a static RAM-like interface with dual-line chip enable (CE) and output enable (OE) control, enabling bus contention avoidance in multi-peripheral systems. Its internal 64-byte page register latches address and data during write operations, freeing the address/data bus for concurrent tasks.
Write completion is confirmed via either DATA polling on I/O7 (complement-to-data behavior) or toggle-bit monitoring on I/O6, both usable at any point during tWC. Hardware protection includes VCC sense (<3.8 V inhibit), 5 ms power-on delay, and noise filtering (<15 ns pulses rejected) - all active without software intervention.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8,192 × 8), organized as byte-addressable nonvolatile storage for firmware parameters or calibration data. |
| Read Access Time | 70 ns maximum - enables direct replacement of SRAM in legacy 5 MHz bus systems without timing redesign. |
| Page Write Cycle | 10 ms maximum - allows burst programming of up to 64 bytes per cycle, reducing host CPU overhead vs. byte-by-byte writes. |
| Supply Voltage | 5 V ±10% - compatible with standard TTL/CMOS logic rails; no auxiliary voltage required. |
| Standby Current | 100 µA CMOS - supports low-power sleep modes in battery-backed or energy-constrained industrial nodes. |
| Endurance | 100,000 write/erase cycles - sufficient for field-updatable configuration storage in PLCs and instrumentation. |
| Data Retention | 10 years at 85°C - validated for long-term deployment in unattended industrial environments. |
Pinout & Package
AT28HC64B-70PI uses a 28-lead PDIP (Plastic Dual Inline Package), 0.600" wide, with JEDEC-standard byte-wide pinout and NC/DC pins clearly defined per Atmel's official package drawing 28P6.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus selecting one of 8,192 memory locations; A6–A12 define page boundaries for 64-byte writes. |
| CE | Chip Enable | Active-low global select; must be low with OE low and WE high for read access; inhibits writes when high. |
| OE | Output Enable | Active-low output gate; controls data bus drivers independently of CE to prevent contention during shared-bus operation. |
| WE | Write Enable | Active-low write strobe; falling edge latches address; rising edge latches data; initiates byte or page programming. |
| I/O0–I/O7 | Bidirectional Data Bus | CMOS/TTL-compatible 8-bit data path; carries input data during writes and output data during reads; supports polling on I/O7/I/O6. |
| GND / VCC | Power Terminals | Ground reference and 5 V supply; decoupling capacitor placement near these pins is critical for stable 70 ns read timing. |
| NC | No Connect | Pin 1 and Pin 28 are explicitly designated NC in PDIP layout - must remain unconnected to avoid functional disruption. |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC Byte-wide Pinout | Direct drop-in compatibility with industry-standard memory sockets and legacy 8-bit microcontroller buses (e.g., 8051, Z80). |
| Hardware Data Protection | VCC sense + 5 ms power-on delay + noise filtering eliminates need for external reset supervisors in power-critical systems. |
| Software Data Protection (SDP) | User-configurable 3-byte command sequence (AAh/55h/A0h) enables selective write lock without hardware modification. |
| Page Write Operation | Internal latching of up to 64 bytes reduces host-side timing constraints - successive bytes must arrive within 150 µs (tBLC). |
| DATA Polling & Toggle Bit | Dual asynchronous write-completion detection methods eliminate fixed delays; supports real-time status checking without dedicated interrupt lines. |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Data |
|---|---|
|
Use Scenario: Storing user-defined I/O mapping, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in factory automation. IC Role / Device Role / Timing Role: Nonvolatile parameter store accessed via parallel bus during boot and runtime; 70 ns read ensures deterministic scan-cycle timing. Use Value: Eliminates battery-backed SRAM while maintaining full compatibility with existing 8-bit controller interfaces and PCB layouts. |
Use Scenario: Retaining sensor calibration coefficients, device serial numbers, and usage logs in portable diagnostic equipment requiring FDA-compliant data integrity. IC Role / Device Role / Timing Role: Secure configuration EEPROM with hardware/software write protection preventing accidental overwrites during field servicing. Use Value: 100,000-cycle endurance and 10-year data retention meet IEC 62304 Class C software requirements for life-critical medical firmware. |
| Automotive Body Control Module (BCM) | Test Equipment Firmware Patch Storage |
|
Use Scenario: Holding seat/mirror position presets, lighting profiles, and CAN node configuration in automotive BCMs operating across –40°C to +85°C. IC Role / Device Role / Timing Role: Industrial-grade parallel EEPROM interfaced to 8-bit MCU; 5 V ±10% supply tolerance accommodates vehicle battery fluctuations. Use Value: Green (Pb/Halide-free) PDIP packaging and extended temperature rating satisfy AEC-Q100 stress test prerequisites for non-safety-critical modules. |
Use Scenario: Storing field-upgradable firmware patches and instrument-specific calibration offsets in benchtop oscilloscopes and signal generators. IC Role / Device Role / Timing Role: In-system programmable memory supporting page writes via JTAG or UART bootloader; toggle-bit detection simplifies host firmware logic. Use Value: 10 ms page write cycle enables <100 ms patch application time - faster than serial EEPROM alternatives and compatible with existing parallel flash sockets. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28HC64B-70JI | Same core silicon, but in 32-lead PLCC package with different pin 1 location and thermal profile. | Suitable for surface-mount production; requires PCB redesign due to 32-pin footprint and JEDEC MS-016 compliance. | Select when automated assembly and higher I/O density are prioritized over through-hole serviceability. |
| AT28HC64B-70SI | Identical electrical specs, but in 28-lead SOIC (0.300" width) with gull-wing leads and lower profile. | Preferred for space-constrained industrial boards; lacks PDIP's mechanical robustness for frequent rework or vibration-prone enclosures. | Choose for compact, high-volume designs where thermal dissipation and board area are critical constraints. |
Compared with AT28HC64B-70JI and AT28HC64B-70SI, the AT28HC64B-70PI offers superior mechanical stability in hand-soldered prototypes and legacy repair scenarios due to its 0.600" PDIP form factor, while retaining identical timing, endurance, and protection features - making it the default choice for development, qualification, and low-volume industrial builds.
Availability
AT28HC64B-70PI is available at Aetrix Electronics and suitable for industrial PLC configuration storage, medical device calibration data retention, and automotive body control module parameter backup requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for AT28HC64B-70PI 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 for industrial, automotive, and consumer applications.
The AT28HC64B product line was designed for high-reliability, pin-compatible replacement of battery-backed SRAM in legacy 8-bit systems - emphasizing fast parallel access, robust write protection, and extended data retention without external support circuitry.
FAQ
What is the maximum read access time specified for the AT28HC64B-70PI?
The AT28HC64B-70PI has a guaranteed maximum read access time of 70 ns under industrial temperature conditions (–40°C to +85°C) and 5 V ±10% supply. This value is measured from address valid to valid data on I/O0–I/O7 and is fully characterized per AC Read Characteristics table in the official Atmel datasheet (0274K–PEEPR–8/08). The "70" in the part number directly denotes this timing grade.
Does the AT28HC64B-70PI support page write operations, and what is the maximum page size?
Yes, the AT28HC64B-70PI supports page write operations with a maximum page size of 64 bytes. During a page write, the device internally latches addresses and data for up to 64 consecutive bytes within the same page (defined by A6–A12), completing the entire write in a single 10 ms internal cycle. Successive bytes must be loaded within 150 µs (tBLC) to remain in page mode - a capability confirmed in Section 4.3 and Table 16 of the datasheet.
How does hardware data protection work on the AT28HC64B-70PI?
Hardware data protection on the AT28HC64B-70PI operates through four mechanisms: (1) VCC sense that inhibits writes if supply drops below ~3.8 V; (2) automatic 5 ms power-on delay before enabling writes; (3) write inhibition when OE is low, CE is high, or WE is high; and (4) noise filtering rejecting input pulses shorter than 15 ns. These features are implemented in silicon and require no firmware interaction, as detailed in Section 4.6.1 of the datasheet.
Can the AT28HC64B-70PI be used in place of standard SRAM in existing designs?
Yes, the AT28HC64B-70PI is designed for SRAM-like read/write operation without external components: CE and OE control read access identically to static RAM, and write cycles initiate automatically after address/data latching. Its JEDEC byte-wide pinout, 5 V supply, and TTL/CMOS compatibility allow direct substitution in many 8-bit systems - though write timing and protection features require minor firmware adaptation per Sections 4.2–4.3 of the datasheet.
What package type is used for the AT28HC64B-70PI, and are there lead-free options?
The AT28HC64B-70PI uses a 28-lead PDIP (Plastic Dual Inline Package), 0.600" wide, with lead finish compliant to RoHS Directive 2011/65/EU. While the "PI" suffix denotes standard PDIP, Atmel also offered green (Pb/Halide-free) variants such as AT28HC64B-70PU (PDIP, Pb-free), documented in Section 27.2 of the datasheet - confirming full material compliance for environmentally regulated deployments.
AT28HC64B-70PI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-DIP (0.600", 15.24mm)
- 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:
- 10ms
- Access Time:
- 70 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-PDIP
AT28HC64B-70PI FAQ
1.How can I place an order for AT28HC64B-70PI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT28HC64B-70PI 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-70PI reliable?
The price and inventory of AT28HC64B-70PI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT28HC64B-70PI is usually 5 days.
3.What payment methods are accepted for AT28HC64B-70PI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT28HC64B-70PI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT28HC64B-70PI?
AT28HC64B-70PI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT28HC64B-70PI 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-70PI?
For technical support, including AT28HC64B-70PI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT28HC64B-70PI requirements.
6.How does Aetrix verify that AT28HC64B-70PI is sourced from the original manufacturer or authorized distributors?
All AT28HC64B-70PI 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-70PI meets industry standards.
7.What is the process for return or replacement of AT28HC64B-70PI?
All AT28HC64B-70PI units undergo pre-shipment inspection (PSI). If there is an issue with AT28HC64B-70PI, 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-70PI part is unused and in its original packaging.
Return procedure for AT28HC64B-70PI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT28HC64B-70PI 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…
