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Microchip Technology AT27C1024-12JC
- Part No.:
- AT27C1024-12JC
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 44-LCC (J-Lead)
- Datasheet:
-
AT27C1024-12JC.pdf
- Description:
- IC EPROM 1MBIT PARALLEL 44PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:1,165
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Product details
Overview
AT27C1024-12JC from Microchip Technology (formerly Atmel) is a 1-Mbit one-time programmable EPROM organized as 64K × 16 bits, operating at 5V ±10%, with 120 ns maximum access time and CMOS/TTL-compatible I/O. It features dual-line control (CE/OE), rapid programming (100 µs/word), and integrated product identification for automated programming systems. Used in legacy microprocessor firmware storage where non-volatility, read speed, and pin compatibility with older EPROMs are critical.
For engineers reviewing the AT27C1024-12JC datasheet, AT27C1024-12JC pinout, AT27C1024-12JC application, or AT27C1024-12JC equivalent, key selection criteria include 40-pin PDIP package compatibility, 120 ns read timing, VPP = 12–13 V programming voltage, standby current ≤100 µA, and support for industrial temperature range (−40°C to +85°C).
Technical Context
The AT27C1024-12JC implements a standard OTP EPROM architecture with address decoding for A0–A15, 16-bit bidirectional data outputs (O0–O15), and two independent enable controls (CE and OE) enabling bus contention avoidance in high-speed 16-bit systems. Its Rapid™ programming algorithm uses precise 100 µs PGM pulses at elevated VCC (6.5 V) and VPP (13.0 V) to achieve reliable single-word programming.
It supports product identification via dedicated A9 voltage sensing (11.5–12.5 V) and A0 toggling to select manufacturer or device code words. System-level design requires local 0.1 µF ceramic decoupling between VCC and GND, plus bulk 4.7 µF electrolytic capacitance for arrays, due to transient sensitivity during CE transitions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 1,048,576 bits (64K × 16); enables full firmware image storage for 16-bit microcontrollers without external multiplexing. |
| Access Time (tACC) | 120 ns max; eliminates WAIT states in 8 MHz Z80 or 10 MHz 8086-based systems. |
| VCC Supply | 5 V ±10%; compatible with standard TTL/CMOS logic rails without regulation overhead. |
| Standby Current (ISB1) | 100 µA max (CMOS CE); allows low-power retention in battery-backed embedded controllers. |
| Programming Voltage (VPP) | 13.0 V ±0.25 V; requires dedicated high-voltage supply rail or charge-pump circuitry in programmers. |
| Operating Temperature | −40°C to +85°C (Industrial grade); validated for use in industrial PLCs and motor drives. |
| Input Compatibility | CMOS and TTL inputs; interoperable with both legacy 74LS and modern 74HC logic families. |
Pinout & Package
AT27C1024-12JC is supplied in a 40-lead, 0.600" wide plastic dual inline package (PDIP), JEDEC MS-011 AC compliant, with 2×20 pin layout and pin 1 identified by notch or dot. Both GND pins (pins 12 and 28) must be connected for stable operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A15 | Address Inputs | 16-bit address bus interface; fully decoded internally to select one of 65,536 words. |
| O0–O15 | Data Outputs | True 16-bit parallel output bus; high-impedance when OE or CE inactive. |
| CE | Chip Enable | Active-low global chip select; disables outputs and reduces ICC to ISB when high. |
| OE | Output Enable | Active-low output gate; allows shared bus operation without disabling chip power state. |
| PGM | Program Strobe | Active-low pulse input triggering 100 µs programming cycle under VPP = 13 V. |
| VPP | Programming Voltage | 12–14 V input required only during programming; must be applied after VCC and removed before VCC. |
| VCC | Power Supply | +5 V main supply; powers logic and output drivers during read and program modes. |
| GND | Ground | Two dedicated ground pins (12, 28); mandatory connection to minimize noise and ensure latchup immunity. |
| NC | No Connect | Pin 21 is unconnected; must remain floating-no external tie or pull-up/down. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming | 100 µs/word typical programming time enables <1 second full-device programming, reducing production test cycle time. |
| Integrated Identification Code | Manufacturer ID (001Eh) and Device Code (00F1h) accessible via A9/A0 control-enables auto-algorithm selection in universal programmers. |
| 200 mA Latchup Immunity | Guarantees robustness against transient overcurrent events on I/O or supply lines in noisy industrial environments. |
| 2000 V ESD Protection | HBM-rated protection allows safe handling and board assembly without special ESD precautions beyond standard practices. |
| JEDEC Standard Packages | Direct drop-in replacement for AT27C516 (512K) and other 40-pin EPROMs-no PCB redesign needed for capacity upgrades. |
Applications
| Industrial PLC Firmware Storage | Legacy 16-Bit Microprocessor Boot ROM |
|---|---|
Use Scenario: Storing fixed ladder logic and I/O mapping tables in programmable logic controllers deployed in factory automation cabinets. IC Role / Device Role / Timing Role: Non-volatile boot memory providing deterministic 120 ns read access to initialization code upon power-up. Use Value: Eliminates reliance on slow serial EEPROM or external flash, ensuring sub-millisecond boot latency and immunity to power interruption during execution. | Use Scenario: Hosting BIOS and peripheral initialization routines in retro-computing or test equipment based on Intel 8086/80286 or Motorola 68000 CPUs. IC Role / Device Role / Timing Role: Primary 16-bit wide instruction ROM mapped into upper memory space, accessed via A0–A15 and O0–O15. Use Value: Matches native 16-bit data bus width-avoids glue logic or byte-lane multiplexing required with 8-bit EPROMs, simplifying board layout and timing closure. |
| Automotive Engine Control Module (ECM) Calibration Data | Medical Diagnostic Instrument Bootloader |
Use Scenario: Holding immutable calibration maps (fuel injection timing, spark advance) in automotive ECMs certified for −40°C to +125°C operation. IC Role / Device Role / Timing Role: Read-only configuration store accessed during engine start sequence; no write operations post-deployment. Use Value: Industrial-grade variant (AT27C1024-12JI) provides guaranteed parametric performance across full temperature range-critical for emission compliance. | Use Scenario: Securing bootloader firmware in FDA-cleared diagnostic devices where firmware integrity must survive repeated power cycles and field updates. IC Role / Device Role / Timing Role: Immutable first-stage loader verifying signature and loading application firmware from external flash or SD card. Use Value: OTP nature prevents accidental or malicious corruption-ensures bootloader remains tamper-proof throughout device lifetime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT27C1024-12PC | Same die, identical timing and programming specs, but in 40-lead PDIP with wider 0.600" body (vs. 0.300" for JC). | Requires PCB footprint change; not pin-compatible due to different lead pitch and body width. | Select only if existing board uses standard JEDEC 40P6 outline and thermal/mounting constraints permit larger package. |
| AM27C1024-12DC | AMD version with same 64K×16 organization and 120 ns access, but higher VPP tolerance (12.5±0.5 V) and slightly higher ISB (150 µA max). | Validated for identical industrial temperature range; pinout matches AT27C1024-12JC exactly. | Drop-in alternative where Atmel supply continuity is constrained; verify VPP regulator stability per AMD datasheet. |
Compared with AT27C1024-12JC, AT27C1024-12PC demands PCB rework due to mechanical incompatibility, while AM27C1024-12DC offers true pin-and-function equivalence with minor VPP/ISB trade-offs-making it the preferred functional alternative for drop-in replacement.
Availability
AT27C1024-12JC is available at Aetrix Electronics and suitable for industrial control systems, legacy computing hardware restoration, and automotive calibration modules requiring stable component supply across extended lifecycle programs.
Supply support for AT27C1024-12JC 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
Microchip Technology acquired Atmel in 2016 and maintains full support for legacy Atmel memory products including the AT27C series.
The AT27C1024 belongs to Atmel's OTP EPROM family, designed specifically for cost-sensitive, high-reliability firmware storage in industrial, automotive, and computing applications where reprogrammability is unnecessary and data permanence is mandatory.
FAQ
What is the programming voltage requirement for AT27C1024-12JC?
The AT27C1024-12JC requires VPP = 13.0 V ± 0.25 V during programming, applied only after VCC reaches 6.5 V and removed before VCC is powered down. This voltage is used exclusively for oxide breakdown during bit programming and is not present during normal read operation. The AT27C1024-12JC datasheet specifies VID on A9 must be 11.5–12.5 V for product identification mode, distinct from VPP.
Can AT27C1024-12JC operate with a 3.3 V supply?
No, AT27C1024-12JC is specified only for 5 V ± 10% operation (4.5 V to 5.5 V). Its internal logic, output drive strength, and programming circuitry are designed for 5 V CMOS/TTL compatibility. Using 3.3 V will result in undefined behavior, failed reads, and inability to enter programming mode. For 3.3 V systems, consider modern SPI NOR flash alternatives-not AT27C1024-12JC.
Does AT27C1024-12JC support in-system programming?
No, AT27C1024-12JC does not support in-system programming. It requires removal from the target board and insertion into a dedicated EPROM programmer capable of delivering 13 V to VPP and generating precise 100 µs PGM pulses. The AT27C1024-12JC lacks serial interfaces, command protocols, or internal state machines for ISP-it is strictly a parallel-programmed OTP device.
What is the meaning of "-12" in AT27C1024-12JC?
The "-12" in AT27C1024-12JC denotes the maximum access time specification: 120 ns (tACC). This speed grade defines worst-case read latency under industrial temperature and voltage conditions. It is not a revision code or date code. Other variants include -45 (45 ns), -55 (55 ns), and -15 (150 ns), all sharing identical functionality and pinout but differing in timing performance.
How many ground pins does AT27C1024-12JC have, and why are both required?
AT27C1024-12JC has two dedicated ground pins: pin 12 and pin 28. Both must be connected to system ground to ensure signal integrity, minimize ground bounce during high-speed output transitions, and maintain latchup immunity. The AT27C1024-12JC datasheet explicitly states "Both GND pins must be connected"-omitting either compromises timing margins, increases noise susceptibility, and risks exceeding absolute maximum ratings.
AT27C1024-12JC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 44-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EPROM
- Technology:
- EPROM - OTP
- Memory Size:
- 1Mbit
- Memory Organization:
- 64K x 16
- 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:
- 44-PLCC (16.6x16.6)
AT27C1024-12JC FAQ
1.How can I place an order for AT27C1024-12JC through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C1024-12JC 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 AT27C1024-12JC reliable?
The price and inventory of AT27C1024-12JC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C1024-12JC is usually 5 days.
3.What payment methods are accepted for AT27C1024-12JC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C1024-12JC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C1024-12JC?
AT27C1024-12JC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C1024-12JC 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 AT27C1024-12JC?
For technical support, including AT27C1024-12JC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C1024-12JC requirements.
6.How does Aetrix verify that AT27C1024-12JC is sourced from the original manufacturer or authorized distributors?
All AT27C1024-12JC 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 AT27C1024-12JC meets industry standards.
7.What is the process for return or replacement of AT27C1024-12JC?
All AT27C1024-12JC units undergo pre-shipment inspection (PSI). If there is an issue with AT27C1024-12JC, 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 AT27C1024-12JC part is unused and in its original packaging.
Return procedure for AT27C1024-12JC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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