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Microchip Technology AT27C020-55TU
- Part No.:
- AT27C020-55TU
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-TFSOP (0.724", 18.40mm Width)
- Datasheet:
-
AT27C020-55TU.pdf
- Description:
- IC EPROM 2MBIT PARALLEL 32TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,545
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Product details
Overview
AT27C020-55TU from Atmel is a 2-Mbit (256K × 8) one-time programmable EPROM with 55 ns read access time, 5V ±10% supply operation, and JEDEC-standard 32-lead TSOP package. It delivers TTL/CMOS-compatible I/O, rapid 100 µs/byte programming, and supports industrial temperature range (–40°C to +85°C) in embedded firmware storage applications.
For engineers reviewing the AT27C020-55TU datasheet, AT27C020-55TU pinout, AT27C020-55TU application, or AT27C020-55TU equivalent, key selection considerations include read timing (tACC = 55 ns), standby current (≤100 µA), dual-line control (CE/OE), OTP reliability for boot code, and TSOP footprint compatibility in space-constrained PCB layouts.
Technical Context
The AT27C020-55TU implements a parallel-addressed OTP memory architecture with 18 address lines (A0–A17) and 8 bidirectional data outputs (O0–O7), controlled by CE and OE for bus contention management. Its Rapid™ programming algorithm uses 13.0 V VPP and 6.5 V VCC during programming, with 100 µs PGM pulses and per-byte verify-reprogram loops.
It features integrated product identification (manufacturer code 0x1E, device code 0x86) accessed via A9 high-voltage mode (11.5–12.5 V), and includes ESD protection (2,000 V) and latch-up immunity (200 mA). Read-mode operation draws ≤8 mA typical ICC at 5 MHz, while standby current remains ≤100 µA with CE high.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2,097,152 bits (256K × 8) - stores full microcontroller boot firmware without external buffering |
| Read Access Time | 55 ns max - eliminates WAIT states in 5 MHz Z80, 8051, or 68K-based systems |
| Supply Voltage | 5V ±10% - compatible with legacy 5V logic rails and avoids level-shifting circuitry |
| Standby Current | 100 µA max - enables low-power retention in battery-backed or intermittent-power systems |
| Programming Speed | 100 µs/byte typical - reduces production programming cycle time vs. standard EPROMs |
| Operating Temp | –40°C to +85°C - qualified for industrial control, motor drives, and factory automation |
| VPP Programming Voltage | 13.0 V ±0.25 V - requires dedicated programming supply; not used in normal read operation |
Pinout & Package
AT27C020-55TU is supplied in a 32-lead Plastic Thin Small Outline Package (TSOP, Type 1, JEDEC MO-142 BD), 11.8 mm × 10.0 mm × 1.0 mm body, gull-wing leads, lead pitch 0.5 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address Inputs | 18-bit address bus interface; selects one of 256K bytes; A0 = LSB, A17 = MSB |
| O0–O7 | Data Outputs | 8-bit bidirectional data bus; outputs valid only when CE = OE = low during read |
| CE | Chip Enable | Active-low global enable; places outputs in high-Z when high, enabling multi-device bus sharing |
| OE | Output Enable | Active-low output gate; allows CE-controlled chip select while permitting output tri-state control |
| PGM | Program Strobe | Active-low pulse input during programming; triggers 100 µs write cycle when VPP = 13 V |
| VPP | Programming Voltage | 13.0 V input during programming only; must be applied after VCC and removed before VCC |
| VCC | Power Supply | +5V ±10% main supply; powers logic and outputs; supplies 8 mA typical in active read mode |
| GND | Ground | Reference return path for all signals and supplies; requires local 0.1 µF ceramic decoupling |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time with automatic verify-and-reprogram up to 10 pulses per byte |
| Integrated Product ID Code | Manufacturer ID (0x1E) and Device ID (0x86) readable via A9 high-voltage mode for automated programmer recognition |
| Dual-Line Control (CE/OE) | Independent chip and output enables allow flexible bus arbitration and eliminate contention in shared-memory systems |
| High-Reliability CMOS Process | 2,000 V HBM ESD rating and 200 mA latch-up immunity ensure robustness in manufacturing and field environments |
| Three JEDEC Packages | TSOP (AT27C020-55TU), PDIP (AT27C020-55PC), and PLCC (AT27C020-55JC) support design reuse across prototyping and volume production |
Applications
| Industrial PLC Firmware Storage | Legacy Microcontroller Boot ROM |
|---|---|
Use Scenario: Fixed-function programmable logic controllers require immutable, field-upgradeable firmware stored in nonvolatile memory. IC Role / Device Role / Timing Role: OTP EPROM providing boot code and configuration tables; accessed via parallel bus at system power-on reset. Use Value: 55 ns access ensures deterministic startup timing; industrial temp rating guarantees operation in cabinet-mounted enclosures up to 85°C. |
Use Scenario: 8-bit and 16-bit microcontrollers (e.g., 8051, Z80, 68HC11) rely on external ROM for initial program load and interrupt vectors. IC Role / Device Role / Timing Role: Primary boot memory mapped into CPU address space; CE/OE timing synchronized to CPU bus cycles. Use Value: TTL/CMOS compatibility eliminates level shifters; 256K capacity accommodates full application firmware without bank switching. |
| Automotive Instrument Cluster Calibration Data | Medical Device Diagnostic Firmware |
Use Scenario: Analog/digital instrument clusters store calibrated sensor offsets, display fonts, and UI logic in tamper-resistant memory. IC Role / Device Role / Timing Role: Nonvolatile storage for calibration constants and static UI assets; programmed once during final test. Use Value: OTP architecture prevents accidental overwrite in vehicle service; automotive-grade variants support –40°C to +125°C ambient. |
Use Scenario: Class II medical devices require traceable, unalterable diagnostic routines and safety-critical boot sequences. IC Role / Device Role / Timing Role: Secure firmware repository verified at power-up; accessed only by trusted host MCU during self-test. Use Value: High-reliability CMOS process and 200 mA latch-up immunity meet IEC 60601-1 EMC and safety requirements. |
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, 120 ns access, 5V, 28-pin PDIP/PLCC - slower, fewer pins, no TSOP option | Limited to legacy 28-pin sockets; lacks Rapid™ programming and ID code features | Use only if board layout restricts to 28-pin footprint and 120 ns timing is acceptable |
| MX27C256-12PC | 256K × 8, 120 ns, 5V, 28-pin PDIP - no PLCC/TSOP, no integrated ID, lower ESD rating (1,500 V) | No high-voltage ID read mode; requires external verification during programming | Select when cost is primary constraint and programming throughput is noncritical |
Compared with AM27C256B-120DC and MX27C256-12PC, the AT27C020-55TU offers faster 55 ns access, TSOP packaging for density-sensitive designs, Rapid™ programming for production efficiency, and electronic ID for automated programming - making it optimal for new industrial and automotive firmware storage where speed, footprint, and programming reliability matter.
Availability
AT27C020-55TU is available at Aetrix Electronics and suitable for industrial control systems, legacy microcontroller boot applications, and automotive instrumentation requiring stable component supply and long-term obsolescence management.
Supply support for AT27C020-55TU 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) designed high-reliability nonvolatile memory and microcontrollers for industrial, automotive, and embedded markets before its 2016 acquisition.
The AT27C020 belongs to Atmel's 27C-series OTP EPROM family, engineered for firmware storage in systems where code immutability, 5V compatibility, and JEDEC-standard packaging are essential - especially in cost-sensitive, high-volume industrial electronics.
FAQ
What is the maximum operating temperature range for the AT27C020-55TU?
The AT27C020-55TU is rated for industrial temperature operation from –40°C to +85°C. This range is confirmed in the Ordering Information table and DC Operating Conditions section of the datasheet. The "TU" suffix specifically denotes the TSOP package with industrial temperature grade. It does not support the automotive (–40°C to +125°C) or commercial (0°C to +70°C) ranges unless explicitly ordered with -JA or -JC suffixes.
Does the AT27C020-55TU require a separate programming voltage during normal read operation?
No, the AT27C020-55TU operates from a single 5V ±10% supply (VCC) during read mode. The VPP pin is only used during programming and must be held at 13.0 V ±0.25 V. During read, VPP may be tied to VCC or left unconnected per design - it has no functional role in read access. The datasheet explicitly states "VPP may be connected directly to VCC except during programming."
How many address and data lines does the AT27C020-55TU have?
The AT27C020-55TU has 18 address inputs (A0 through A17) and 8 data outputs (O0 through O7), matching its 256K × 8 organization (218 = 262,144 addresses × 8 bits = 2,097,152 bits). Pin diagrams confirm A0–A17 and O0–O7 are dedicated, unidirectional (inputs/outputs) in read mode, with no multiplexing or internal address latching.
Is the AT27C020-55TU pin-compatible with other 32-lead TSOP EPROMs like the 27C020 from other manufacturers?
No documented pin-to-pin compatibility exists between the AT27C020-55TU and generic "27C020" TSOP parts from other vendors. While pin count and outline match JEDEC MO-142 BD, signal assignments (e.g., PGM, VPP, A17 placement) and AC timing differ. Substitution requires validation of address mapping, control timing (tCE, tOE), and programming voltage requirements - not guaranteed across brands.
What decoupling capacitance is required for stable operation of the AT27C020-55TU?
The datasheet mandates a 0.1 µF high-frequency ceramic capacitor between VCC and GND, placed as close as possible to the AT27C020-55TU pins. For boards with multiple EPROMs, a 4.7 µF bulk electrolytic capacitor is also required near the power entry point. These values are specified in the "System Considerations" section to suppress transients during CE transitions and maintain VCC stability within datasheet limits.
AT27C020-55TU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-TFSOP (0.724", 18.40mm Width)
- Packaging:
- Tray
- 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:
- 55 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-TSOP
AT27C020-55TU FAQ
1.How can I place an order for AT27C020-55TU through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C020-55TU 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 AT27C020-55TU reliable?
The price and inventory of AT27C020-55TU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C020-55TU is usually 5 days.
3.What payment methods are accepted for AT27C020-55TU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C020-55TU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C020-55TU?
AT27C020-55TU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C020-55TU 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 AT27C020-55TU?
For technical support, including AT27C020-55TU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C020-55TU requirements.
6.How does Aetrix verify that AT27C020-55TU is sourced from the original manufacturer or authorized distributors?
All AT27C020-55TU 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 AT27C020-55TU meets industry standards.
7.What is the process for return or replacement of AT27C020-55TU?
All AT27C020-55TU units undergo pre-shipment inspection (PSI). If there is an issue with AT27C020-55TU, 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 AT27C020-55TU part is unused and in its original packaging.
Return procedure for AT27C020-55TU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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