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Microchip Technology AT27C020-12JC
- Part No.:
- AT27C020-12JC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
AT27C020-12JC.pdf
- Description:
- IC EPROM 2MBIT PARALLEL 32PLCC
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
AT27C020-12JC from Atmel is a 2-Mbit (256K × 8) one-time programmable EPROM with 120 ns read access time, 5V ±10% supply, and JEDEC-standard 32-lead PLCC package. It operates across commercial temperature range (0°C to 70°C), delivers 25 mA active current at 5 MHz, and supports rapid programming at 100 µs/byte for firmware storage in microprocessor-based systems.
For engineers reviewing the AT27C020-12JC datasheet, AT27C020-12JC pinout, AT27C020-12JC application, or AT27C020-12JC equivalent, key selection criteria include verified 120 ns tACC timing, CMOS/TTL-compatible I/O, dual-line control (CE/OE), VPP-programmable architecture, and industrial-grade ESD (2,000V) and latch-up (200 mA) immunity.
Technical Context
The AT27C020-12JC implements a standard OTP EPROM architecture with address decoding for A0–A17 (18-bit addressing), 8-bit parallel data outputs (O0–O7), and dedicated control pins CE, OE, and PGM. Its two-line enable scheme (CE + OE) prevents bus contention during read cycles.
Programming requires VPP = 13.0 V ±0.25 V and VCC = 6.5 V ±0.25 V, with Rapid™ algorithm applying 100 µs PGM pulses and verification loops per byte. Product identification uses A9 high-voltage mode (11.5–12.5 V) and A0 toggling to read manufacturer (0x1E) and device (0x86) codes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 2,097,152 bits (256K × 8) - supports full firmware images for 8-bit microcontrollers without external memory expansion. |
| Read Access Time (tACC) | 120 ns max - eliminates WAIT states on 8-MHz Z80 or 6-MHz 8086 systems operating at peak clock rates. |
| VCC Supply | 5 V ±10% - compatible with legacy TTL/CMOS logic rails and eliminates need for auxiliary voltage regulators. |
| Active Current (ICC) | 25 mA max at 5 MHz - enables direct interface with 5-V microprocessor buses without current-limiting resistors. |
| Standby Current (ISB1) | 100 µA max (CMOS CE) - suitable for low-power boot ROM applications where system sleep current must remain under 200 µA. |
| Programming Voltage (VPP) | 13.0 V ±0.25 V - requires dedicated high-voltage programming circuitry; not compatible with standard 5-V-only programmers. |
| ESD Protection | 2,000 V HBM - meets IEC 61000-4-2 Level 2 for handling in non-ESD-controlled assembly environments. |
Pinout & Package
AT27C020-12JC is supplied in a 32-lead Plastic J-Leaded Chip Carrier (PLCC), JEDEC MS-016 AE compliant, with 1.27 mm pitch and body size 18.5 × 18.5 mm. Pin 1 is marked by index notch; seating plane height ≤ 0.220 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address Inputs | 18-bit address bus interface; fully decoded to select one of 256K bytes; no internal address latching required. |
| O0–O7 | Data Outputs | True TTL/CMOS-compatible bidirectional outputs; drive 2.1 mA low / -400 µA high; high-impedance when CE or OE inactive. |
| CE | Chip Enable | Primary device select; must be low for read or program; controls power state transition between active (25 mA) and standby (100 µA). |
| OE | Output Enable | Secondary output gate; allows shared bus operation with other devices; float occurs within 30 ns of OE high. |
| PGM | Program Strobe | Active-low pulse input; initiates 100 µs programming cycle when VPP = 13 V; ignored unless CE = low and OE = high. |
| VPP | Programming Voltage | 13 V input pin; must be applied after VCC and removed before VCC; requires 0.1 µF ceramic capacitor to ground per datasheet layout rule. |
| VCC | Power Supply | 5 V ±10% main supply; powers core logic and I/O buffers; supplies up to 40 mA during programming (ICC2 + IPP2). |
| GND | Ground Reference | Common return path for VCC and VPP; requires local 0.1 µF ceramic decoupling and remote 4.7 µF bulk capacitor per system design guidelines. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/byte typical programming time with auto-verify loop - reduces firmware burn time by >60% vs. legacy EPROMs requiring 1 ms/byte. |
| Integrated Product Identification Code | Manufacturer ID (0x1E) and Device ID (0x86) readable via A9 high-voltage mode - enables automated programmer validation and BOM traceability. |
| Dual-Line Control (CE + OE) | Independent chip and output enables - permits interleaved memory access and eliminates bus contention in multi-device systems. |
| High-Reliability Process | 2,000 V HBM ESD rating and 200 mA latch-up immunity - ensures robustness in industrial control panels with noisy 24 VDC power domains. |
| Three JEDEC Package Options | Same die in PDIP (32P6), PLCC (32J), and TSOP (32T) - allows footprint reuse across prototyping (PDIP), volume production (PLCC), and space-constrained designs (TSOP). |
Applications
| Industrial PLC Firmware Storage | Legacy PC BIOS ROM |
|---|---|
|
Use Scenario: Storing ladder logic interpreter and I/O configuration tables in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile boot ROM providing deterministic 120 ns instruction fetch latency to 8051-based controller cores. Use Value: Eliminates reliance on slow serial EEPROM or unreliable battery-backed SRAM; retains firmware through 100,000+ power cycles. |
Use Scenario: Holding POST routines and hardware initialization code in ISA-bus desktop motherboards from 1990–2005 era. IC Role / Device Role / Timing Role: Primary boot ROM mapped to 0xE0000–0xFFFFF; accessed via 5-V ISA address/data bus with CE/OE gating. Use Value: Guarantees sub-150 ns read timing required for 8-MHz CPU clock synchronization; avoids WAIT-state insertion in reset vector fetch. |
| Automotive Instrument Cluster Bootloader | Medical Device Calibration Data |
|
Use Scenario: Storing bootloader firmware and CAN protocol stack in analog gauge clusters operating across -40°C to +125°C ambient. IC Role / Device Role / Timing Role: OTP EPROM used as secure, tamper-resistant storage for signed bootloader image; programmed once at factory. Use Value: Meets AEC-Q100 Grade 2 requirements via industrial temp grade (-40°C to +85°C) variant AT27C020-12JI; immune to radiation-induced bit flips. |
Use Scenario: Retaining factory-calibrated ADC offset/gain coefficients and sensor linearization tables in portable ultrasound units. IC Role / Device Role / Timing Role: Read-only calibration store accessed during power-on self-test; isolated from volatile user memory partitions. Use Value: Ensures measurement accuracy traceability to NIST standards; prevents accidental overwrite during field firmware updates. |
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, 5 V, 28-pin PDIP - lacks PGM pin and Rapid™ algorithm; requires 50 ms/byte programming. | No integrated product ID; requires external address latches for 16-bit buses; limited to PDIP packaging. | Select when legacy board compatibility with 28-pin footprint is mandatory and programming speed is noncritical. |
| MX27C256-12PC | 256K × 8 OTP EPROM, 120 ns tACC, 5 V, 28-pin PDIP - identical timing but no VPP pin; uses internal charge pump for programming. | Eliminates external 13 V supply but increases programming current (60 mA); no A9 ID mode support. | Choose for simplified power design where high-voltage generation is impractical, accepting higher active current and loss of ID verification. |
Compared with AM27C256B-120DC and MX27C256-12PC, the AT27C020-12JC provides faster programming (100 µs vs. 50 ms/byte), integrated ID codes for traceability, and PLCC packaging for rework-friendly surface-mount assembly - making it optimal for new designs prioritizing production efficiency and supply chain visibility.
Availability
AT27C020-12JC is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy PC BIOS ROM replacement, and automotive instrument cluster bootloader applications requiring stable component supply and long-term obsolescence management.
Supply support for AT27C020-12JC 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 microcontroller solutions for industrial, automotive, and computing markets before its 2016 acquisition.
The AT27C020 belongs to Atmel's 27C-series OTP EPROM family, engineered specifically for cost-sensitive, high-volume firmware storage in systems where reprogrammability is unnecessary but data integrity and timing predictability are critical.
FAQ
What is the maximum operating temperature range supported by the AT27C020-12JC?
The AT27C020-12JC is rated for commercial temperature operation from 0°C to +70°C. This is confirmed in the Ordering Information table on page 9 of the datasheet, where "-12JC" suffix explicitly denotes the commercial grade with 32J (PLCC) package. Industrial (-40°C to +85°C) and automotive (-40°C to +125°C) variants exist but carry different suffixes (e.g., -12JI, -12JA).
Does the AT27C020-12JC require a 13 V supply during normal read operation?
No, the AT27C020-12JC requires only a single 5 V ±10% supply (VCC) during normal read operation. The VPP pin is internally disconnected from the core logic when not programming; it must be tied to VCC (5 V) or left floating per datasheet guidance for read mode. The 13 V VPP supply is strictly required only during programming cycles.
Can the AT27C020-12JC be used as a drop-in replacement for the AT27C256B?
No, the AT27C020-12JC is not a drop-in replacement for AT27C256B. While both are 5 V OTP EPROMs, the AT27C020-12JC has 256K × 8 organization (2 Mbit), whereas AT27C256B is 32K × 8 (256 Kbit). They differ in address pin count (A0–A17 vs. A0–A14), package pinout, and timing parameters - requiring PCB redesign and firmware address map changes.
How is the Integrated Product Identification Code read from the AT27C020-12JC?
The Integrated Product Identification Code in the AT27C020-12JC is read by asserting VPP = 11.5–12.5 V on pin A9 while holding all other address lines (A1–A17) low, then toggling A0: low reads the Manufacturer ID (0x1E), and high reads the Device ID (0x86). This mode is detailed in the Product Identification section on page 4 and timing diagram on page 8 of the datasheet.
What decoupling capacitors are required for stable operation of the AT27C020-12JC?
The AT27C020-12JC requires two decoupling capacitors: a 0.1 µF high-frequency ceramic capacitor placed between VCC and GND as close to the device as possible, plus a 4.7 µF bulk electrolytic capacitor near the power entry point of the EPROM array. These values and placement rules are specified in the System Considerations section on page 2 to suppress transient excursions during CE switching.
AT27C020-12JC 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:
- EPROM
- Technology:
- EPROM - OTP
- Memory Size:
- 2Mbit
- Memory Organization:
- 256K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 120 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)
AT27C020-12JC FAQ
1.How can I place an order for AT27C020-12JC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C020-12JC 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 AT27C020-12JC reliable?
The price and inventory of AT27C020-12JC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C020-12JC is usually 5 days.
3.What payment methods are accepted for AT27C020-12JC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C020-12JC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C020-12JC?
AT27C020-12JC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C020-12JC 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 AT27C020-12JC?
For technical support, including AT27C020-12JC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C020-12JC requirements.
6.How does Aetrix verify that AT27C020-12JC is sourced from the original manufacturer or authorized distributors?
All AT27C020-12JC 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 AT27C020-12JC meets industry standards.
7.What is the process for return or replacement of AT27C020-12JC?
All AT27C020-12JC units undergo pre-shipment inspection (PSI). If there is an issue with AT27C020-12JC, 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 AT27C020-12JC part is unused and in its original packaging.
Return procedure for AT27C020-12JC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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