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Microchip Technology AT27C020-90PC
- Part No.:
- AT27C020-90PC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-DIP (0.600", 15.24mm)
- Datasheet:
-
AT27C020-90PC.pdf
- Description:
- IC EPROM 2MBIT PARALLEL 32DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,420
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Product details
Overview
AT27C020-90PC from Atmel is a 2-Mbit (256K × 8) one-time programmable EPROM designed for firmware storage in microprocessor systems. It delivers 55 ns read access time, operates on a single 5V ±10% supply, and supports commercial temperature range (0°C to 70°C) in a 32-lead 600-mil PDIP package. Its dual-line control (CE/OE) prevents bus contention in embedded boot memory applications.
For engineers reviewing the AT27C020-90PC datasheet, AT27C020-90PC pinout, AT27C020-90PC application, or AT27C020-90PC equivalent, key selection criteria include verified 55 ns tACC timing, 100 µA max standby current, JEDEC-standard PDIP compatibility, Rapid™ programming at 100 µs/byte, and CMOS/TTL I/O interoperability with legacy 8-bit controllers.
Technical Context
The AT27C020-90PC implements OTP EPROM architecture with address decoding for A0–A17 (18-bit), 8-bit parallel data outputs (O0–O7), and dedicated program control via PGM and VPP pins. It uses high-reliability CMOS technology with 2,000V ESD protection and 200 mA latch-up immunity.
Its two-line enable scheme (CE and OE) enables flexible bus interface timing-CE controls device selection while OE gates output drivers, allowing independent control of chip activation and data output enabling. Programming requires 13.0V VPP and 6.5V VCC, with verification performed per-byte using the Rapid™ algorithm.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2,097,152 bits (256K × 8); sufficient for full BIOS/firmware images in 8-bit microcontroller boot loaders. |
| Read Access Time (tACC) | 90 ns max; ensures no WAIT states required on 11 MHz Z80 or 8 MHz 8051 systems. |
| VCC Supply | 5V ±10%; compatible with standard TTL/CMOS logic rails without regulation overhead. |
| Standby Current (ISB1) | 100 µA max (CMOS CE); enables low-power retention in battery-backed systems. |
| Active Current (ICC) | 25 mA max at 5 MHz; supports sustained burst reads without thermal derating. |
| Programming Speed | 100 µs/byte typical; reduces production programming cycle time by >4× vs. legacy EPROMs. |
| Operating Temperature | 0°C to 70°C (Commercial); validated for office, lab, and non-automotive industrial environments. |
Pinout & Package
AT27C020-90PC is packaged in a 32-lead, 0.600" wide plastic dual in-line package (PDIP), JEDEC MS-011 compliant, with 0.1" lead pitch and through-hole mounting.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VPP) | Programming Voltage Input | Accepts 12.0V ±0.5V during programming; must be ramped after VCC and before removal. |
| 2–19, 22–32 (A0–A17, O0–O7, CE, OE, PGM, VCC, GND) | Address/Data/Control/Power | A0–A17: 18-bit address bus; O0–O7: bidirectional data bus in read mode; CE/OE: active-low chip/output enables; PGM: active-low program strobe. |
| 20 (GND) | Ground Reference | Primary signal return; requires local 0.1 µF ceramic decoupling per device. |
| 21 (VCC) | Power Supply | 5V ±10% main supply; must be applied simultaneously with or before VPP during programming. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time with built-in verify-and-reprogram loop, reducing factory programming throughput time. |
| Integrated Product Identification Code | Manufacturer ID (0x1E) and Device Code (0x86) readable via A9/VH and A0 toggle, enabling automatic algorithm selection in universal programmers. |
| Two-Line Control Architecture | Independent CE and OE enables precise bus arbitration-OE can float outputs while CE remains asserted, preventing contention during DMA transfers. |
| CMOS/TTL-Compatible I/O | VIL ≤ 0.8V, VIH ≥ 2.0V, VOL ≤ 0.4V, VOH ≥ 2.4V; interoperable with both legacy TTL and modern CMOS microcontrollers without level-shifting. |
| High-Reliability Process | 2,000V HBM ESD rating and 200 mA latch-up immunity ensure robustness in manual handling and noisy industrial PCB environments. |
Applications
| Industrial PLC Firmware Storage | Legacy PC BIOS Memory |
|---|---|
Use Scenario: Storing fixed ladder logic and I/O configuration in modular PLC backplanes where field updates are rare but reliability is critical. IC Role / Device Role / Timing Role: Non-volatile boot memory providing deterministic 90 ns read latency to 80C188-based controller during power-on initialization. Use Value: Eliminates need for external wait-state generators and supports direct execution from memory due to guaranteed tACC compliance. |
Use Scenario: Holding POST routines and hardware initialization code in ISA-bus desktop motherboards from the mid-1990s. IC Role / Device Role / Timing Role: Primary ROM mapped at 0xF0000–0xFFFFF; accessed via 20-bit address bus with CE driven by A20 gate and OE by IORC#. Use Value: Pin-compatible replacement for earlier 27C256 devices with faster access and lower active current, extending system uptime in fanless enclosures. |
| Medical Instrument Boot Loader | Point-of-Sale Terminal Configuration |
Use Scenario: Storing immutable bootloader and safety-critical calibration constants in Class II medical devices requiring long-term data retention (>10 years). IC Role / Device Role / Timing Role: OTP memory holding signed firmware signature and hardware revision ID, read once at power-up before RAM initialization. Use Value: One-time programmability prevents accidental overwrite; integrated ID code enables automated version verification during manufacturing test. |
Use Scenario: Storing localized language strings, tax tables, and peripheral driver offsets in embedded ARM7-based POS terminals deployed globally. IC Role / Device Role / Timing Role: Static memory mapped into XMEM space of NXP LPC2103; accessed via 8-bit data bus with glue logic decoding CE/OE. Use Value: 100 µA max standby current extends battery backup life during overnight shutdown; PDIP package allows easy rework in high-mix assembly lines. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C256B-120DC | 256K × 8 OTP EPROM; 120 ns tACC; 5V only; no VPP pin (uses internal charge pump); PLCC/PDIP options. | Slower access invalidates use in 12 MHz 8086 systems; lacks VPP-driven programming control for high-voltage margin testing. | Select when board layout already accommodates slower timing and external 12V generation is undesirable. |
| MX27C256-12PC | 256K × 8 OTP EPROM; 120 ns tACC; requires 12.5V VPP; same PDIP-32 footprint; Atmel-compatible pinout. | Higher VPP tolerance (12.5V vs. 12.0V) improves programming yield in marginal voltage conditions; identical CE/OE timing behavior. | Choose for drop-in replacement where tighter VPP regulation is unavailable, provided 120 ns timing budget exists. |
Compared with AM27C256B-120DC and MX27C256-12PC, the AT27C020-90PC provides the fastest verified access (90 ns), strict 12.0V VPP control for repeatable programming, and integrated identification codes-making it optimal for high-volume, timing-critical firmware storage where traceability and speed are prioritized over ultra-low-cost sourcing.
Availability
AT27C020-90PC is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy PC BIOS memory, and medical instrument boot loader applications requiring stable component supply across extended product lifecycles.
Supply support for AT27C020-90PC 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 was a U.S.-based semiconductor company specializing in microcontrollers, non-volatile memory, and RF solutions before its acquisition by Microchip Technology in 2016.
The AT27C020-90PC belongs to Atmel's 27C-series OTP EPROM family, engineered for reliable, cost-effective firmware storage in 8-bit and 16-bit embedded systems where field reprogrammability is unnecessary but long-term data integrity is mandatory.
FAQ
What is the maximum operating temperature range for the AT27C020-90PC?
The AT27C020-90PC is rated for commercial operation from 0°C to 70°C. This range is confirmed in the Ordering Information table on page 9 of the datasheet, where "-90PC" explicitly denotes the PDIP package with commercial temperature grade. It is not qualified for industrial (−40°C to +85°C) or automotive (−40°C to +125°C) use.
Does the AT27C020-90PC require an external 12V supply for normal read operation?
No, the AT27C020-90PC requires only a single 5V ±10% supply for read operation. The 12V VPP pin is used exclusively during programming and must be disconnected or held at 5V during read mode. The datasheet specifies VPP = X (don't care) in Read Mode on page 4's Operating Modes table.
How many address lines does the AT27C020-90PC support, and what is the total memory capacity?
The AT27C020-90PC supports 18 address lines (A0–A17), enabling access to 218 = 262,144 locations. With an 8-bit data bus (O0–O7), this yields a total capacity of 256K × 8 = 2,097,152 bits (2 Mbit), as stated in the device description on page 1.
Can the AT27C020-90PC be used as a direct replacement for the AT27C256 in existing designs?
No-the AT27C020-90PC is not a pin-compatible or functional replacement for the AT27C256. The AT27C256 is 32K × 8 (256 Kbit), uses A0–A14 (15 address lines), and has different pin assignments (e.g., no A15–A17). The AT27C020-90PC requires full 18-bit addressing and occupies the same physical footprint but with distinct signal mapping.
What decoupling capacitance is required for stable operation of the AT27C020-90PC?
The AT27C020-90PC requires a minimum 0.1 µF high-frequency ceramic capacitor between VCC and GND, placed as close to the device as possible. For boards with multiple EPROMs, a 4.7 µF bulk electrolytic capacitor should also be added near the power entry point, as specified in the System Considerations section on page 2.
AT27C020-90PC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-DIP (0.600", 15.24mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EPROM
- Technology:
- EPROM - OTP
- Memory Size:
- 2Mbit
- Memory Organization:
- 256K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 90 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 32-PDIP
AT27C020-90PC FAQ
1.How can I place an order for AT27C020-90PC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C020-90PC 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 AT27C020-90PC reliable?
The price and inventory of AT27C020-90PC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C020-90PC is usually 5 days.
3.What payment methods are accepted for AT27C020-90PC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C020-90PC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C020-90PC?
AT27C020-90PC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C020-90PC 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 AT27C020-90PC?
For technical support, including AT27C020-90PC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C020-90PC requirements.
6.How does Aetrix verify that AT27C020-90PC is sourced from the original manufacturer or authorized distributors?
All AT27C020-90PC 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 AT27C020-90PC meets industry standards.
7.What is the process for return or replacement of AT27C020-90PC?
All AT27C020-90PC units undergo pre-shipment inspection (PSI). If there is an issue with AT27C020-90PC, 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 AT27C020-90PC part is unused and in its original packaging.
Return procedure for AT27C020-90PC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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