27C512-15FA - 512Kbit CMOS UV EPROM 150ns CDIP-28 | ASI
MPN: 27C512-15FA β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.8 | $1.80 |
| 10 | $1.75 | $17.50 |
| 100 | $1.7 | $170.00 |
| 200 | $1.696 | $339.20 |
| 1,000 | $1.65 | $1,650.00 |
Drop-in alternatives for 27C512-15FA β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
27C512-20
β Drop-Inβ In Stock
$4.1 / Unit
View Datasheet β27C512-15F6
β Drop-Inπ Reference alternative (not in catalog)
AM27C512-150DC
β Drop-Inπ Reference alternative (not in catalog)
27C512-15
β Drop-Inπ Reference alternative (not in catalog)
M27C512-15F1
β Drop-Inπ Reference alternative (not in catalog)
27C512-15FA Maximum Ratings & Electrical Characteristics
| Memory Size | 512 Kbit (64K x 8) |
| Organization | 65,536 x 8 bit |
| Memory Type | CMOS UV EPROM (UVPROM) |
| Access Time | 150 ns |
| Supply Voltage | 5 V (typical operating) |
| Package | CDIP-28 (ceramic DIP, 0.600 in / 15.24 mm, UV window) |
| Number of Terminals | 28 |
| Technology | CMOS |
| Mounting Type | Through Hole |
| Temperature Grade | Commercial |
| Erase Method | Ultraviolet light (quartz window) |
| Programming Method | Standard EPROM programmer (elevated VPP) |
| Interface Type | Parallel |
27C512-15FA Pin Configuration
| Pin 1 | A15 β Address input bit 15 (highest address line for 64K x 8 organization) |
| Pin 2 | A12 β Address input bit 12 |
| Pin 3 | A7 β Address input bit 7 |
| Pin 4 | A6 β Address input bit 6 |
| Pin 5 | A5 β Address input bit 5 |
| Pin 6 | A4 β Address input bit 4 |
| Pin 7 | A3 β Address input bit 3 |
| Pin 8 | A2 β Address input bit 2 |
| Pin 9 | A1 β Address input bit 1 |
| Pin 10 | A0 β Address input bit 0 (LSB) |
| Pin 11 | O0 β Data output bit 0 (LSB) |
| Pin 12 | O1 β Data output bit 1 |
| Pin 13 | O2 β Data output bit 2 |
| Pin 14 | GND β Ground reference |
| Pin 15 | O3 β Data output bit 3 |
| Pin 16 | O4 β Data output bit 4 |
| Pin 17 | O5 β Data output bit 5 |
| Pin 18 | O6 β Data output bit 6 |
| Pin 19 | O7 β Data output bit 7 (MSB) |
| Pin 20 | /CE β Chip enable (active low) - device select / program control |
| Pin 21 | A10 β Address input bit 10 |
| Pin 22 | /OE/VPP β Output enable (active low) / programming supply voltage |
| Pin 23 | A11 β Address input bit 11 |
| Pin 24 | A9 β Address input bit 9 |
| Pin 25 | A8 β Address input bit 8 |
| Pin 26 | A13 β Address input bit 13 |
| Pin 27 | A14 β Address input bit 14 |
| Pin 28 | VCC β Power supply (+5 V typical) |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this digital IC. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
27C512-15FA is suitable for 6 applications: Legacy Industrial Equipment Firmware, Arcade Game and Retro-Computer Boards, BIOS and Boot ROM Storage, Telecommunications Line Cards, Test and Measurement Instrument Firmware, Automotive and Machinery ECU Repair.
Legacy Industrial Equipment Firmware
The 27C512-15FA fits firmware storage in legacy industrial controllers, PLCs and motor-drive boards that were designed around windowed 28-pin EPROM sockets and cannot migrate to surface-mount flash without PCB redesign. Its 150 ns access time matches the bus timing of 8/16-bit microprocessors from that era, and the 64K x 8 organization maps directly onto a single 64 KB code space segment. The ceramic package with UV window lets field engineers erase and reload firmware during updates, then permanently cover the window for deployment. Because supply comes from active legacy-stock channels, it remains a practical repair part for equipment with 20+ year service lives.
Recommended
Arcade Game and Retro-Computer Boards
Retro computing and arcade restoration communities rely on the 27C512-15FA to replace failed or corrupt program ROMs in 1980s/90s game PCBs and home computers. The 512-Kbit (64K x 8) density exactly matches banked game code images, and the standard 28-pin pinout drops directly into original sockets. Its 150 ns access time covers the 1-2 MHz-class processor timing of classic boards with margin. The UV window allows hobbyists to iterate on ROM-hack images with a low-cost EPROM eraser and programmer, then label the window for final installation, keeping original hardware authentic and code-swappable.
Recommended
BIOS and Boot ROM Storage
Older motherboards, embedded single-board computers, and telecommunications line cards used 28-pin EPROMs for BIOS and boot code. The 27C512-15FA provides 64 KB of boot code with 150 ns access, sufficient for zero-wait-state fetch at 8-16 MHz bus clocks when combined with processor cache behavior. The parallel interface requires no serial configuration, so a failed BIOS chip can be swapped in seconds during board-level repair. The ceramic windowed package supports repeated re-flashing during development; for deployed units the window is covered, making the device read-only for the remainder of its service life.
Recommended
Telecommunications Line Cards
Carrier and PBX line cards from the 1990s commonly stored firmware and lookup tables in 512-Kbit windowed EPROMs. The 27C512-15FA's 5 V parallel interface and 150 ns access time match the EPROM sockets and timing chains designed into these cards, and its commercial temperature grade suits central-office environments. UV erasability allowed carriers to update feature sets by swapping programmed devices during maintenance windows rather than replacing entire cards. Given the long deployment lifetimes of telecom infrastructure, active sourcing of 27C512 family parts remains essential for sustaining installed bases and avoiding full card redesigns.
Recommended
Test and Measurement Instrument Firmware
Bench instruments such as oscilloscopes, logic analyzers, and signal generators from the EPROM era store calibration routines and UI firmware in 28-pin windowed devices. The 27C512-15FA's deterministic 150 ns access time and non-volatile 64K x 8 storage suit firmware that executes directly from the EPROM without preload RAM. Its UV window supports factory re-programming when calibration code revisions ship, and service manuals from that era routinely list 27C512 sockets for replacement. Restoring these instruments with a correctly programmed 27C512-15FA preserves original functionality and calibration workflows.
Recommended
Automotive and Machinery ECU Repair
Engine ECUs, transmission controllers, and industrial machinery control boards from the 1980s-90s often hold fuel/spark maps and control code in a single 27C512 socket. The 27C512-15FA's 150 ns access time meets the processor timing of these controllers, and its ceramic windowed package allows tuners to iterate on calibrations with UV erasure between dyno runs before sealing the final map under an opaque label. Because many of these ECUs remain in service in classic vehicles and installed machinery, windowed 27C512 devices are the standard replacement part for keeping these systems operational.
Recommended
Recommended Products Summary
Engineering reference data for 27C512-15FA β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 27C512-20 | 27C512-15F6 | AM27C512-150DC | 27C512-15 |
|---|---|---|---|---|---|
| Package | CDIP-28 (UV window) | CDIP-28 (UV window) | 28-CDIP (0.600 in, window) | CDIP-28 | CDIP-28 |
| Brand | ASI | ASI | STMicroelectronics | AMD | Macronix International |
| Memory Organization | 64K x 8 (512 Kbit) | 64K x 8 (512 Kbit) | 64K x 8 (512 Kbit) | 64K x 8 (512 Kbit) | 64K x 8 (512 Kbit) |
| Access Time | 150 ns | 200 ns | 150 ns | 150 ns | 150 ns |
| Technology | CMOS UV EPROM | CMOS UV EPROM | CMOS UV EPROM | CMOS UV EPROM | CMOS EPROM |
| UV Erase Window | Yes | Yes | Yes | Yes | Yes |
| Temperature Grade | Commercial | Commercial | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
| Unit Price (1 pc, as of 2026-09-13) | $1.80 | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- 150 ns access time with UV re-erasability (vs 27C512-20)
- Same pinout and speed at potentially lower cost (vs 27C512-15F6)
- Documented multi-vendor availability (vs AM27C512-150DC)
Design Notes
The 27C512-15FA is a through-hole 0.600-inch (15.24 mm) wide 28-pin ceramic DIP. Verify the PCB footprint width before ordering: many legacy boards used 0.600-inch EPROM sockets, but some designs used narrower 0.300-inch sockets for smaller 27-series parts. Use a machined-pin or dual-wipe socket for field-replaceable firmware; avoid direct soldering if future UV erasure is anticipated, since desoldering a 28-pin ceramic package risks pad damage.
Never leave the quartz erase window exposed in service. UV components in sunlight or fluorescent light can partially erase over weeks to months, causing intermittent bit errors that mimic hardware faults. Apply an opaque, UV-opaque label over the window after final programming. Also confirm the speed grade on the marking: a -20 (200 ns) part substituted for a -15 (150 ns) part will fail only under worst-case bus timing, producing intermittent crashes that are hard to diagnose.
Although 150 ns access time is generous by modern standards, keep address-line trace lengths on large memory boards within the original design's timing budget, and decouple VCC with a 0.1 uF ceramic capacitor close to pin 28 with a short return path to pin 14. EPROM outputs drive full CMOS levels, but long un-terminated buses from that era can ring; series damping resistors (22-47 ohm) on data lines are an optional improvement in repaired boards.
Compliance Information
Distributor data (IC Components Limited) lists the Lead Free Status / RoHS Status field as unspecified for this part. Ceramic DIP legacy memory devices are frequently RoHS-exempt; request a compliance certificate from the supplier.
