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Microchip Technology AT29C020-90JC
- Part No.:
- AT29C020-90JC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT29C020-90JC.pdf
- Description:
- IC FLASH 2MBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
AT29C020-90JC from Atmel is a 2-megabit (256K × 8) 5-volt-only Flash memory IC organized as 262,144 bytes, featuring 70 ns read access time, 10 ms sector program cycle time, 10,000 write/erase endurance, and dual 8K-byte boot blocks with independent programming lockout - used in embedded system firmware storage and BIOS code retention.
For engineers reviewing the AT29C020-90JC datasheet, AT29C020-90JC pinout, AT29C020-90JC application, or AT29C020-90JC equivalent, key selection considerations include sector-based reprogramming timing, hardware/software data protection mechanisms, boot block lockout behavior, and PLCC-32 package compatibility with legacy socketed designs.
Technical Context
The AT29C020-90JC implements sector-erase-and-program architecture with 1024 × 256-byte sectors, internal address/data latches for full-sector loading, and automatic erase-before-program sequencing controlled by an on-chip timer. It supports both hardware- and software-initiated chip erase via 6-byte command sequences.
Its dual boot blocks (first and last 8K bytes) support independent lockout activation using a 7-command algorithm; once enabled, locked blocks prevent all erase/program operations and disable chip-erase functionality. Data polling (I/O7 complement) and toggle-bit (I/O6) methods provide real-time program cycle completion detection without external timing dependencies.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 2 Mbit (262,144 × 8), enabling full BIOS or bootloader storage in single-package solution |
| Read Access Time | 90 ns max - defines minimum bus cycle time for CPU read operations under commercial temperature range |
| Sector Program Time | 10 ms typical - sets minimum interval between successive sector writes during firmware updates |
| Endurance | >10,000 program/erase cycles per sector - supports field-upgradable firmware with long service life |
| Supply Voltage | 5 V ±10% - eliminates need for dedicated programming voltage, simplifying power design |
| Standby Current | 100 µA (CMOS, 0°C–70°C) - enables low-power retention in battery-backed systems |
| Operating Range | 0°C to +70°C - validated for commercial-grade industrial control and PC peripheral applications |
| Package | 32-lead PLCC (J-lead) - surface-mount compatible with through-hole socket adapters and legacy rework workflows |
Pinout & Package
AT29C020-90JC uses a 32-lead Plastic J-Leaded Chip Carrier (PLCC) package with standard JEDEC MS-016, Variation AE footprint. Pin 1 identifier is a corner notch; body dimensions are 12.47 mm × 14.96 mm × 3.35 mm (max height).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address Inputs | 18-bit address bus supporting full 256K-byte addressing; A0–A7 select byte within sector, A8–A17 select sector |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel interface; I/O7 used for DATA polling, I/O6 for toggle-bit status monitoring |
| CE | Chip Enable | Active-low global device select; must be low for read, program, or identification modes |
| OE | Output Enable | Active-low output control; high during program cycles to prevent bus contention |
| WE | Write Enable | Active-low command strobe; falling edge latches address/data during byte load and program initiation |
| NC | No Connect | Two unconnected pins (Pin 1 and Pin 32 in PLCC top view) - must remain floating, not tied to VCC/GND |
| VCC | Power Supply | +5 V ±10% main supply; powers core logic and I/O buffers; requires local 0.1 µF decoupling |
| GND | Ground Reference | Signal and power ground return; shared with system PCB ground plane for noise immunity |
Key Features
| Feature | Design Value |
|---|---|
| Single 5V Reprogramming | Eliminates need for 12V programming supplies - reduces BOM count and layout complexity in embedded hosts |
| Hardware Data Protection | VCC sense (3.8V threshold), 5ms power-on delay, and noise filtering (<15 ns pulses rejected) prevent spurious writes during brown-out or EMI events |
| Software Data Protection | Three-command sequence (AAh/55h/A0h) enables/disables write access - allows runtime-controlled firmware update gating |
| Boot Block Lockout | Independent enable/disable of lower (0x00000–0x01FFF) and upper (0x3E000–0x3FFFF) 8K blocks - secures boot code against accidental overwrite |
| DATA Polling & Toggle Bit | Real-time program status via I/O7 complement or I/O6 toggling - removes dependency on fixed timing delays in host firmware |
| CMOS/TTL Compatibility | VIH = 2.0 V min, VIL = 0.8 V max, VOH = 2.4 V min at -400 µA - interoperable with 5V microcontrollers and FPGAs without level shifters |
Applications
| Industrial PLC Firmware Storage | Legacy PC BIOS Retention |
|---|---|
Use Scenario: Storing configuration logic and motion control algorithms in programmable logic controllers where field updates occur infrequently but require absolute reliability. IC Role / Device Role / Timing Role: Nonvolatile firmware storage with sector-level reprogrammability; boot block lockout protects startup routines from corruption during partial updates. Use Value: 10,000-cycle endurance ensures >10-year service life with quarterly firmware patches; 90 ns read speed meets real-time scan cycle timing budgets. | Use Scenario: Holding BIOS code in desktop motherboards and add-in cards requiring socketed, field-replaceable memory with proven legacy compatibility. IC Role / Device Role / Timing Role: EPROM-replacement Flash memory accessed identically to standard ROM during POST; CE/OE dual-control prevents bus conflicts during DMA transfers. Use Value: PLCC-32 package fits existing ZIF sockets; 5V-only operation avoids redesign of 5V-only motherboard power rails. |
| Medical Device Bootloader | Automotive Infotainment Update Cache |
Use Scenario: Securing certified bootloader code in Class II medical instruments where regulatory compliance mandates immutable startup firmware. IC Role / Device Role / Timing Role: Dual boot block lockout isolates verified bootloader (lower 8K) from updatable application partition (remaining 248K); lockout state detectable via software identification mode. Use Value: FE/FF readback at 00002H/3FFF2H provides runtime verification of lockout status - satisfies IEC 62304 traceability requirements. | Use Scenario: Caching over-the-air (OTA) firmware images in automotive head units prior to validation and installation, requiring robust sector erase before write. IC Role / Device Role / Timing Role: High-reliability intermediate storage with hardware write inhibit (VCC sense) preventing corruption during vehicle ignition cycling or battery transients. Use Value: 100 µA standby current minimizes parasitic drain on 12V battery; 10 ms sector program time enables rapid image staging during parking-mode updates. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM29LV020B-90JC | 3.0 V–3.6 V supply only; 90 ns access; 100,000 endurance; no boot block lockout | Requires 3.3 V rail; lacks hardware-secured boot region; higher endurance suits frequent OTA updates | Select when migrating to 3.3 V systems and boot security is handled externally |
| MX29LV020CTI-90G | 3.0 V–3.6 V supply; 90 ns access; 100,000 endurance; top/bottom boot block with WP# pin control | Uses dedicated write-protect pin instead of software lockout; different command set for sector erase | Choose for simplified hardware-based protection and compatibility with MXIC reference designs |
Compared with AM29LV020B-90JC and MX29LV020CTI-90G, the AT29C020-90JC uniquely supports 5 V-only operation and software-configurable boot block lockout - critical for maintaining compatibility with legacy 5 V control systems and enabling flexible, firmware-defined security policies.
Availability
AT29C020-90JC is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy PC BIOS retention, medical device bootloader, and automotive infotainment update cache requiring stable component supply across extended product lifecycles.
Supply support for AT29C020-90JC 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 nonvolatile memory, microcontrollers, and secure authentication ICs for industrial and embedded markets.
The AT29C020-90JC belongs to Atmel's legacy 5V Flash memory product line, designed specifically for drop-in replacement of EPROMs in cost-sensitive, long-lifecycle applications where 5V system architecture and socketed upgradeability remain essential.
FAQ
What is the maximum operating temperature range for the AT29C020-90JC?
The AT29C020-90JC is rated for commercial temperature operation from 0°C to +70°C, as indicated by the "C" suffix in its ordering code. It is not qualified for industrial (-40°C to +85°C) use - for that, the AT29C020-90JI variant must be selected. This range ensures reliable performance in office equipment, consumer PCs, and non-extreme industrial enclosures where ambient heat buildup is controlled.
Does the AT29C020-90JC support true random-access reads like an EPROM?
Yes, the AT29C020-90JC supports true random-access reads identical to standard EPROMs: when CE and OE are low and WE is high, the addressed byte appears on I/O0–I/O7 within 90 ns. Its dual-line CE/OE control allows flexible bus arbitration - for example, holding OE high while CE toggles enables fast sequential reads without bus contention, matching classic EPROM timing behavior.
How does the boot block lockout feature work on the AT29C020-90JC?
The AT29C020-90JC contains two independent 8K-byte boot blocks - one at addresses 0x00000–0x01FFF (lower) and another at 0x3E000–0x3FFFF (upper). Lockout is enabled via a 7-command software algorithm; once activated, neither block can be erased or programmed. Status is readable at 00002H (lower) and 3FFF2H (upper): FEh means unlocked, FFh means locked. The AT29C020-90JC retains lockout state across power cycles.
Can the AT29C020-90JC be programmed in-system without removing it from the PCB?
Yes, the AT29C020-90JC is explicitly designed for in-system programming (ISP) using only 5 V. Sector programming requires no external high-voltage signals: commands are issued via standard WE/CE/OE strobes and address/data bus transactions. Host firmware initiates byte loads, sector erases, and software protection - making the AT29C020-90JC suitable for field-upgradable embedded systems without requiring socket removal or external programmers.
What package type does the AT29C020-90JC use, and is it RoHS-compliant?
The AT29C020-90JC uses a 32-lead Plastic J-Leaded Chip Carrier (PLCC) package, designated "32J" in Atmel's ordering matrix. Per Atmel's 2002 documentation and Microchip's legacy compliance records, this variant was manufactured prior to RoHS Directive 2002/95/EC enforcement and contains leaded solder in its J-leads; it is not RoHS-compliant. For RoHS-compliant alternatives, consult Microchip's current AT29 series or consider migration to MX29LV020C-family devices.
AT29C020-90JC 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:
- FLASH
- Technology:
- FLASH
- Memory Size:
- 2Mbit
- Memory Organization:
- 256K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 10ms
- Access Time:
- 90 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (13.97x11.43)
AT29C020-90JC FAQ
1.How can I place an order for AT29C020-90JC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT29C020-90JC 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 AT29C020-90JC reliable?
The price and inventory of AT29C020-90JC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT29C020-90JC is usually 5 days.
3.What payment methods are accepted for AT29C020-90JC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT29C020-90JC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT29C020-90JC?
AT29C020-90JC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT29C020-90JC 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 AT29C020-90JC?
For technical support, including AT29C020-90JC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT29C020-90JC requirements.
6.How does Aetrix verify that AT29C020-90JC is sourced from the original manufacturer or authorized distributors?
All AT29C020-90JC 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 AT29C020-90JC meets industry standards.
7.What is the process for return or replacement of AT29C020-90JC?
All AT29C020-90JC units undergo pre-shipment inspection (PSI). If there is an issue with AT29C020-90JC, 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 AT29C020-90JC part is unused and in its original packaging.
Return procedure for AT29C020-90JC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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