My Inquiry
My Account
Microchip Technology AT27C020-55PU
- Part No.:
- AT27C020-55PU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-DIP (0.600", 15.24mm)
- Datasheet:
-
AT27C020-55PU.pdf
- Description:
- IC EPROM 2MBIT PARALLEL 32DIP
- Quantity:
- Payment:
- Shipping:
Inventory:471
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT27C020-55PU from Atmel is a 256K × 8-bit, one-time programmable EPROM (OTP EPROM) with 55 ns read access time, 5V ±10% supply operation, and CMOS/TTL-compatible I/O. It delivers low active current (25 mA max at 5 MHz) and ultra-low standby current (100 µA max), enabling reliable firmware storage in microprocessor systems without wait states. Used in industrial control firmware boot memory and legacy embedded BIOS storage.
For engineers reviewing the AT27C020-55PU datasheet, AT27C020-55PU pinout, AT27C020-55PU application, or AT27C020-55PU equivalent, key selection factors include verified 55 ns tACC timing, PDIP-32 package compatibility, rapid 100 µs/byte programming, integrated product ID code, and industrial temperature range (-40°C to +85°C) compliance.
Technical Context
The AT27C020-55PU implements a parallel-addressed OTP EPROM architecture with dual-line control (CE and OE) for bus contention prevention. Its address space spans A0–A17 (18-bit), supporting 262,144 bytes, and uses VPP = 12.0 V ±0.5 V during programming with PGM strobe control.
It features two distinct operating modes: standard read (VPP = VCC) and rapid programming (VPP = 13.0 V ±0.25 V, VCC = 6.5 V ±0.25 V). Product identification is accessed via A9 high-voltage enable (11.5–12.5 V) and A0 toggling to select manufacturer (0x1E) or device code (0x86).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 256K × 8 bits (2,097,152 bits); supports full 8-bit data bus interface without byte masking. |
| Read access time | 55 ns max (tACC); eliminates WAIT states in 5 MHz Z80, 80C86, and 68000-based systems. |
| VCC supply | 5 V ±10%; single-supply operation simplifies power design versus multi-rail EPROMs. |
| Standby current | 100 µA max (ISB1); enables low-power retention in battery-backed or intermittent-read systems. |
| Programming speed | 100 µs/byte typical; reduces production programming cycle time by >90% vs. legacy 10 ms/byte EPROMs. |
| ESD protection | 2,000 V HBM; meets industrial handling requirements without external protection diodes. |
| Latchup immunity | 200 mA; prevents destructive latchup under transient overvoltage or ground bounce. |
Pinout & Package
AT27C020-55PU is supplied in a 32-lead plastic dual inline package (PDIP), 0.600" wide (JEDEC 32P6), with 0.100" lead pitch and matte tin finish. Pin 1 identifier is a beveled corner; leads are gull-wing formed for through-hole mounting.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address inputs | 18-bit address bus; fully decoded to access any of 262,144 bytes without external demultiplexing. |
| O0–O7 | Data outputs | True TTL/CMOS-compatible 8-bit bidirectional data bus; drives standard logic loads directly. |
| CE | Chip enable | Active-low global enable; disables outputs and reduces ICC to ISB when high, preventing bus contention. |
| OE | Output enable | Active-low output gate; allows CE-controlled chip selection while permitting shared data bus timing control. |
| PGM | Program strobe | Active-low pulse input; initiates 100 µs programming window synchronized with address and VPP. |
| VPP | Programming voltage | 12.0 V ±0.5 V input; must be applied simultaneously with or after VCC and removed simultaneously or before VCC. |
| GND | Ground reference | Signal and power return; requires local 0.1 µF ceramic decoupling per device per datasheet Figure 3-1. |
| VCC | Power supply | 5 V ±10% main supply; powers core logic and I/O; supplies up to 25 mA during active read cycles. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid programming algorithm | 100 µs/byte typical; enables full 256K-byte programming in <26 seconds, reducing test floor dwell time. |
| Integrated product ID code | Manufacturer ID (0x1E) and device ID (0x86) readable via A9 high-voltage mode; ensures automated programmer compatibility. |
| Two-line control (CE/OE) | Independent chip and output gating; permits interleaved memory access and avoids bus conflicts in multi-device systems. |
| Industrial temperature range | -40°C to +85°C operation; validated across full range for use in motor drives, PLCs, and instrumentation. |
| Green (Pb/halide-free) packaging | RoHS-compliant matte tin lead finish; satisfies EU Directive 2011/65/EU without requiring process requalification. |
Applications
| Industrial Firmware Storage | Legacy Microprocessor Boot ROM |
|---|---|
|
Use Scenario: Storing fixed firmware for programmable logic controllers (PLCs) and CNC motion controllers where field updates are rare but reliability is critical. IC Role / Device Role / Timing Role: Nonvolatile boot memory mapped to CPU address space; provides deterministic 55 ns instruction fetch latency. Use Value: Eliminates mechanical wear and write endurance limits of EEPROM; retains data >20 years without refresh. |
Use Scenario: Providing boot code for Z80, 8086, and 68000-based industrial computers deployed before flash memory adoption. IC Role / Device Role / Timing Role: Primary ROM in reset vector mapping; operates at full system clock speed without wait-state insertion. Use Value: Matches vintage CPU timing budgets; supports direct execution from address lines A0–A17 without glue logic. |
| Automotive ECU Calibration Memory | Medical Device Configuration Storage |
|
Use Scenario: Holding calibrated sensor lookup tables and actuator trim values in engine control units certified for -40°C to +125°C operation. IC Role / Device Role / Timing Role: Read-only configuration store accessed during startup; isolated from runtime software writes. Use Value: Immune to accidental overwrite or corruption; withstands automotive load dump transients due to 200 mA latchup immunity. |
Use Scenario: Storing FDA-approved device calibration constants and safety-critical initialization parameters in Class II medical analyzers. IC Role / Device Role / Timing Role: Immutable parameter repository; accessed once at power-on and verified via checksum before operation. Use Value: Meets IEC 62304 traceability requirements; product ID code enables audit-ready version verification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C256B-70PU | 32K × 8-bit (256 Kbit), 70 ns access, same PDIP-32 package, no VPP pin required (5 V-only programming) | Lower density; suitable for smaller boot images; lacks rapid programming and ID code features | Select when firmware size ≤32 KB and simplified programming infrastructure is prioritized over speed and traceability |
| MX27C256-12PC | 32K × 8-bit, 120 ns access, 5 V-only, no PGM/VPP pins, CMOS-only I/O (not TTL-compatible) | Slower timing; incompatible with TTL bus drivers; no product ID or rapid programming | Choose only for cost-sensitive, non-TTL legacy systems where 120 ns latency is acceptable and traceability is not required |
Compared with AT27C020-55PU, AT27C256B-70PU offers simpler 5 V programming but sacrifices density and rapid programming; MX27C256-12PC reduces cost and pin count but compromises speed, TTL compatibility, and firmware traceability-making AT27C020-55PU the only option supporting full 256 KB, 55 ns, and ID-code–enabled production line verification.
Availability
AT27C020-55PU is available at Aetrix Electronics and suitable for industrial firmware storage, legacy microprocessor boot ROM, and automotive ECU calibration memory requiring stable component supply and long-term obsolescence management.
Supply support for AT27C020-55PU 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 U.S.-based semiconductor company specializing in microcontrollers, nonvolatile memory, and secure authentication ICs for industrial, automotive, and consumer applications.
The AT27C020 belongs to Atmel's OTP EPROM product line, designed specifically for high-reliability, low-volume firmware storage in systems where field reprogrammability is unnecessary but data integrity and timing predictability are essential.
FAQ
What is the maximum operating temperature range for the AT27C020-55PU?
The AT27C020-55PU is rated for industrial temperature operation from -40°C to +85°C. This range is validated per datasheet Section 7 ordering information and Table 5-2, ensuring reliable read performance and data retention under sustained thermal stress in factory automation and outdoor equipment environments. The AT27C020-55PU does not support extended automotive (-40°C to +125°C) operation unless explicitly ordered as the -55AU variant.
Does the AT27C020-55PU require a separate programming voltage (VPP) during normal read operation?
No, the AT27C020-55PU operates with only a single 5 V ±10% supply (VCC) during normal read mode. VPP is required exclusively during programming and verification cycles, where it must be set to 12.0 V ±0.5 V. During read, VPP may be tied to VCC per datasheet Table 5-3 Note 2, and the AT27C020-55PU draws only 25 mA max active current and 100 µA max standby current under those conditions.
How is the product identification code accessed on the AT27C020-55PU?
The AT27C020-55PU product identification code is accessed by asserting A9 at 11.5–12.5 V (VID) while holding A1–A17 low, then toggling A0: low for manufacturer ID (0x1E), high for device ID (0x86). This mode is defined in datasheet Table 5-1 and Figure 5-1, and requires compatible programming hardware capable of precise A9 voltage control. The AT27C020-55PU integrates this feature to enable automated programmer recognition and firmware version auditing.
Can the AT27C020-55PU be used as a drop-in replacement for the AT27C010 or AT27C040?
No, the AT27C020-55PU is not a drop-in replacement for AT27C010 (128K×8) or AT27C040 (512K×8) due to differences in address bus width (A0–A17 vs. A0–A16 or A0–A18) and timing parameters. While all share the same PDIP-32 package footprint, the AT27C020-55PU requires 18 address lines and exhibits 55 ns access time-distinct from the 70 ns or 90 ns specs of other family members. System-level validation of address decoding and timing margins is mandatory before substitution.
What decoupling capacitance is required for stable operation of the AT27C020-55PU?
The AT27C020-55PU requires a minimum 0.1 µF high-frequency ceramic capacitor between VCC and GND, placed as close as possible to the device pins, per datasheet Section 3. For systems with multiple EPROMs, an additional 4.7 µF bulk electrolytic capacitor should be located near the power entry point. These values prevent transient voltage excursions during CE switching and ensure stable 55 ns read timing; omitting them risks data corruption or nonconformance to AC specifications.
AT27C020-55PU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-DIP (0.600", 15.24mm)
- Packaging:
- Tube
- Product Status:
- Active
- 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:
- 55 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 32-PDIP
AT27C020-55PU FAQ
1.How can I place an order for AT27C020-55PU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C020-55PU 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 AT27C020-55PU reliable?
The price and inventory of AT27C020-55PU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C020-55PU is usually 5 days.
3.What payment methods are accepted for AT27C020-55PU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C020-55PU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C020-55PU?
AT27C020-55PU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C020-55PU 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 AT27C020-55PU?
For technical support, including AT27C020-55PU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C020-55PU requirements.
6.How does Aetrix verify that AT27C020-55PU is sourced from the original manufacturer or authorized distributors?
All AT27C020-55PU 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 AT27C020-55PU meets industry standards.
7.What is the process for return or replacement of AT27C020-55PU?
All AT27C020-55PU units undergo pre-shipment inspection (PSI). If there is an issue with AT27C020-55PU, 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 AT27C020-55PU part is unused and in its original packaging.
Return procedure for AT27C020-55PU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT27C020-55PU 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…
