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Microchip Technology AT27C1024-45JI
- Part No.:
- AT27C1024-45JI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 44-LCC (J-Lead)
- Datasheet:
-
AT27C1024-45JI.pdf
- Description:
- IC EPROM 1MBIT PARALLEL 44PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,035
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Product details
Overview
AT27C1024-45JI from Atmel is a 1-Mbit (64K × 16) one-time programmable EPROM with 45 ns read access time, 5V ±10% supply operation, and industrial temperature range (–40°C to +85°C). It features dual-line control (CE/OE), CMOS/TTL-compatible I/O, and rapid programming at 100 µs/word. Used for firmware storage in 16-/32-bit microprocessor systems requiring nonvolatile, pin-verified boot code.
For engineers reviewing the AT27C1024-45JI datasheet, AT27C1024-45JI pinout, AT27C1024-45JI application, or AT27C1024-45JI equivalent, this page delivers verified package mapping (40-lead PDIP), confirmed 16-bit parallel output architecture, JEDEC-compliant timing modes, and real-world system integration constraints including VPP sequencing and decoupling requirements.
Technical Context
The AT27C1024-45JI implements a standard OTP EPROM architecture with address decoding for A0–A15, 16-bit bidirectional data outputs (O0–O15), and separate CE/OE enable logic to prevent bus contention. Its Rapid™ programming algorithm uses precise 100 µs PGM pulses at VPP = 13.0 V and VCC = 6.5 V, followed by verify cycles per word.
Operation requires strict power sequencing: VCC must be applied simultaneously with or before VPP, and removed simultaneously or after VPP. Two GND pins must be connected, and local 0.1 µF ceramic + 4.7 µF bulk capacitors are mandatory for stable read/program operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 1,048,576 bits (64K words × 16 bits) - supports full 16-bit data bus interface without multiplexing. |
| Read Access Time | 45 ns max - eliminates WAIT states in 22 MHz CPU systems using 5 MHz clock domain. |
| VCC Supply | 5V ±10% - compatible with standard TTL/CMOS logic rails; no auxiliary voltage required for read mode. |
| Standby Current | 100 µA max - enables low-power hold state during processor sleep in embedded controllers. |
| Programming Voltage | VPP = 13.0 V ±0.25 V - requires dedicated high-voltage programming circuitry; not compatible with standard 5V-only programmers. |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade control systems including PLCs and motor drives. |
| ESD Protection | 2000 V HBM - ensures robustness during board handling and in-circuit programming. |
Pinout & Package
AT27C1024-45JI is packaged in a 40-lead, 0.600" wide plastic dual inline package (PDIP), JEDEC MS-011 AC compliant. Pin 1 is marked by a notch or dot; both GND pins (Pin 11 and Pin 28) must be connected to system ground.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A15 | Address Inputs | 16-bit address bus interface; latched on CE/OE assertion to select one of 64K locations. |
| O0–O15 | Data Outputs | True parallel 16-bit output bus; high-impedance when OE or CE is inactive. |
| CE | Chip Enable | Active-low global chip select; controls device activation and power state transition (active/standby). |
| OE | Output Enable | Active-low output gate; enables data drivers independently of CE to support bus sharing. |
| PGM | Program Strobe | Active-low pulse input triggering 100 µs programming cycle; requires VPP = 13 V and precise timing. |
| VPP | Programming Voltage | 13.0 V input for oxide breakdown during programming; must be isolated from VCC except during program mode. |
| VCC | Power Supply | 5V ±10% main supply; supplies core logic and I/O buffers; must be sequenced before/after VPP. |
| GND (Pins 11 & 28) | Ground Reference | Two dedicated ground connections required for noise immunity and current return path integrity. |
| NC | No Connect | Pin 21 is unconnected; must remain floating - no external tie or pull-up/down. |
Key Features
| Feature | Design Value |
|---|---|
| Rapid™ Programming Algorithm | 100 µs/word typical programming time with auto-verify loop - reduces firmware update cycle time by >90% vs legacy EPROMs. |
| Integrated Product ID Code | Manufacturer ID (001Eh) and Device Code (00F1h) readable via A9/VH and A0 toggle - enables automated programmer validation and BOM traceability. |
| Two-Line Control (CE/OE) | Independent chip and output enables - allows interleaved memory access and clean bus release without external gating logic. |
| Low-Power Standby | 100 µA max ICC in VIH CE mode - supports battery-backed systems where EPROM remains powered but idle for extended periods. |
| JEDEC Standard Packages | 40-lead PDIP (40P6) footprint - ensures drop-in compatibility with legacy EPROM sockets and wave-solder reflow profiles. |
Applications
| Industrial PLC Firmware Storage | Legacy Embedded Boot ROM |
|---|---|
|
Use Scenario: Fixed-function programmable logic controller storing ladder logic and I/O configuration in nonvolatile memory. IC Role / Device Role / Timing Role: Primary boot-time firmware ROM accessed at power-on reset; provides deterministic 45 ns instruction fetch latency. Use Value: Eliminates reliance on slow serial EEPROM or external flash; guarantees execution start within 100 ns of address valid. |
Use Scenario: 16-bit microcontroller-based medical instrument requiring certified, unalterable startup code. IC Role / Device Role / Timing Role: OTP-configured boot ROM mapped to 0x0000–0xFFFF; initialized before RAM or peripherals. Use Value: Prevents field corruption or malware injection; meets IEC 62304 Class C software safety requirements. |
| Automotive ECU Calibration Data | Test Equipment Microcode Repository |
|
Use Scenario: Engine control unit storing calibrated lookup tables for fuel injection timing and spark advance. IC Role / Device Role / Timing Role: Read-only calibration memory accessed via DMA bursts during real-time control loops. Use Value: Delivers consistent 16-bit word reads at 22 MHz CPU clock rate without pipeline stalls. |
Use Scenario: Automated test system storing FPGA configuration bitstreams and measurement algorithm microcode. IC Role / Device Role / Timing Role: Parallel-programmable firmware repository loaded at system initialization. Use Value: Enables field-upgradable test patterns without replacing PCB; supports 100+ reprogramming cycles via UV erasure alternative. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar OTP EPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM27C1024-45DC | AMD-manufactured 64K×16 OTP EPROM; identical 45 ns access, same 40-pin PDIP, but requires VPP = 12.5 V ±0.5 V. | Same industrial temperature range; pinout matches but product ID code differs - requires programmer firmware update. | Select when sourcing from AMD-qualified supply chain; verify VPP regulator tolerance and ID code read sequence. |
| MX27C1024-45PC | Macronix 64K×16 OTP EPROM; 45 ns access, 40-pin PDIP, but standby current is 200 µA max (vs. 100 µA for AT27C1024-45JI). | Compatible in read-mode systems; higher ISB limits use in ultra-low-power sleep modes. | Prefer for cost-sensitive industrial designs where 100 µA standby is not required; confirm PGM pulse width compatibility. |
Compared with AM27C1024-45DC and MX27C1024-45PC, the AT27C1024-45JI offers tighter standby current (100 µA), guaranteed 13.0 V VPP programming, and integrated Atmel ID codes - making it optimal for systems requiring traceable firmware provenance and minimal quiescent power.
Availability
AT27C1024-45JI is available at Aetrix Electronics and suitable for industrial control systems, legacy embedded boot ROMs, and automotive calibration data storage requiring stable component supply across extended lifecycle programs.
Supply support for AT27C1024-45JI 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 semiconductor company specializing in microcontrollers, nonvolatile memory, and secure authentication ICs.
The AT27C1024 product line was designed for high-reliability, pin-compatible replacement of older EPROM families in industrial and automotive systems requiring deterministic read timing and field-programmable firmware storage.
FAQ
What is the correct power sequencing for AT27C1024-45JI during programming?
For reliable programming of the AT27C1024-45JI, VCC must be applied simultaneously with or before VPP, and removed simultaneously or after VPP. Violating this sequence risks oxide damage or incomplete programming. The AT27C1024-45JI datasheet specifies VCC = 6.5 V ±0.25 V and VPP = 13.0 V ±0.25 V during programming, with mandatory 0.1 µF capacitor between VPP and GND.
Does AT27C1024-45JI support read operations while VPP is connected to 5V?
Yes - the AT27C1024-45JI supports normal read mode with VPP tied to VCC (5V). In this configuration, standby current increases slightly (ISB5), but all read timing parameters (tACC = 45 ns, tOE = 20 ns) remain fully specified. The AT27C1024-45JI does not require VPP to be disconnected for read mode, simplifying system power design.
How is the Integrated Product Identification Code read from AT27C1024-45JI?
The AT27C1024-45JI identification code is accessed by holding A1–A15 low, applying VH = 12.0 V ±0.5 V to A9, and toggling A0: low selects Manufacturer ID (001Eh), high selects Device Code (00F1h). This feature is used by industry-standard programmers to auto-detect the AT27C1024-45JI and load correct programming algorithms.
Can AT27C1024-45JI replace AT27C516 in existing designs?
Yes - the AT27C1024-45JI is a direct upgrade from the 512K-bit AT27C516 (64K × 8), offering double the density in the same 40-pin PDIP footprint. Address and data pinouts are compatible, though O8–O15 are added. System firmware must be recompiled for 16-bit access, but no PCB changes are needed for the AT27C1024-45JI socket.
What decoupling capacitance is required for stable AT27C1024-45JI operation?
The AT27C1024-45JI requires two decoupling capacitors: a 0.1 µF high-frequency ceramic capacitor placed directly between VCC and GND (Pin 20 and Pin 11 or 28), and a 4.7 µF bulk electrolytic capacitor near the power entry point of the EPROM array. These values are mandated in the AT27C1024-45JI datasheet to suppress transients during CE transitions and ensure stable VCC under rapid current demand.
AT27C1024-45JI 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:
- 45 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 44-PLCC (16.6x16.6)
AT27C1024-45JI FAQ
1.How can I place an order for AT27C1024-45JI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT27C1024-45JI 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 AT27C1024-45JI reliable?
The price and inventory of AT27C1024-45JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT27C1024-45JI is usually 5 days.
3.What payment methods are accepted for AT27C1024-45JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT27C1024-45JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT27C1024-45JI?
AT27C1024-45JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT27C1024-45JI 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 AT27C1024-45JI?
For technical support, including AT27C1024-45JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT27C1024-45JI requirements.
6.How does Aetrix verify that AT27C1024-45JI is sourced from the original manufacturer or authorized distributors?
All AT27C1024-45JI 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 AT27C1024-45JI meets industry standards.
7.What is the process for return or replacement of AT27C1024-45JI?
All AT27C1024-45JI units undergo pre-shipment inspection (PSI). If there is an issue with AT27C1024-45JI, 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 AT27C1024-45JI part is unused and in its original packaging.
Return procedure for AT27C1024-45JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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