27C512-20 - 512Kbit EPROM 200ns CMOS 64Kx8 | Fujitsu
Référence : 27C512-20 ✗ Fin de vie| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $6.5 | $6,50 |
| 10 | $5.85 | $58,50 |
| 100 | $5.2 | $520,00 |
| 500 | $4.68 | $2 340,00 |
| 1 000 | $4.1 | $4 100,00 |
27C512-20 Présentation
An EPROM (Erasable Programmable Read-Only Memory) is a non-volatile semiconductor memory that retains programmed data permanently until erased by ultraviolet light through a quartz window. Within the memory hierarchy, EPROM sits alongside OTP ROM and mask ROM as firmware storage, preceding modern Flash devices. The 27C512 family is the 512 Kbit member of the industry-standard 27xx series, organized as 64K addresses of 8 bits each.
Key features of the 27C512-20 include the 200 ns address access time, low CMOS power consumption in standby mode, asynchronous operation requiring no clock, and a JEDEC-standard pinout shared across the 27C512 family from multiple manufacturers. The 3-state outputs allow direct bus connection with other memory or peripheral devices on a shared data bus.
The CMOS process keeps active and standby currents low compared with bipolar NMOS predecessors, which matters in battery-backed and embedded controller systems. The ceramic LCC package with UV-erase window allows repeated reprogramming during development, unlike OTP variants, though programming voltage and algorithm must follow the manufacturer datasheet.
Typical applications include legacy embedded controller firmware storage, industrial equipment BIOS and boot code, arcade and retro-computing game cartridges, and telecom line-card configuration memory where 5V-only, JEDEC-pinout non-volatile storage is required.
Designers should verify program voltage (VPP) requirements and programming pulse timing before inserting the device into a programmer, as programming algorithms differ between CMOS EPROM families even when the read-mode pinout is identical.
This page synthesizes cross-reference data, drop-in alternatives from multiple manufacturers, and practical design notes not consolidated in any single manufacturer datasheet.
Alternatives de remplacement direct pour 27C512-20 — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec 27C512-20 (même facteur de forme et même empreinte) — différant par Memory Type, Package, Organization, Access Time, Erase Method.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
M27C512-20XF1
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AT27C512R-70PU
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
TC57512AD
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
M5M27C512AK
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
W27C512-45
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
GLS27SF512
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
27C512-20/K
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
27C512-20 Valeurs maximales et caractéristiques électriques
| Type de mémoire | UV EPROM |
| Technology | CMOS |
| Density | 512 Kbit (524,288 bits) |
| Organisation de la mémoire | 64K x 8 |
| Maximum Access Time | 200 ns |
| Supply Voltage (VCC) | 5 V |
| Outputs | 3-state |
| Operation | Asynchronous |
| Boîtier | CQCC32 / LCC32 (ceramic, UV window) |
| Type de montage | Surface Mount |
| Erase Method | Ultraviolet light |
| Interface | Parallel |
| Word Size | 8 bit |
| Address Count | 65,536 words |
Configuration des broches de 27C512-20
| Broche 1 | A15 — Address input bit 15 |
| Broche 2 | A12 — Address input bit 12 |
| Broche 3 | A7 — Address input bit 7 |
| Broche 4 | A6 — Address input bit 6 |
| Broche 5 | A5 — Address input bit 5 |
| Broche 6 | A4 — Address input bit 4 |
| Broche 7 | A3 — Address input bit 3 |
| Broche 8 | A2 — Address input bit 2 |
| Broche 9 | A1 — Address input bit 1 |
| Broche 10 | A0 — Address input bit 0 |
| Broche 11 | Q0 — Data output bit 0 (3-state) |
| Broche 12 | Q1 — Data output bit 1 (3-state) |
| Broche 13 | Q2 — Data output bit 2 (3-state) |
| Broche 14 | GND — Ground |
| Broche 15 | Q3 — Data output bit 3 (3-state) |
| Broche 16 | Q4 — Data output bit 4 (3-state) |
| Broche 17 | Q5 — Data output bit 5 (3-state) |
| Broche 18 | Q6 — Data output bit 6 (3-state) |
| Broche 19 | Q7 — Data output bit 7 (3-state) |
| Broche 20 | /E — Chip enable (active low) |
| Broche 21 | A10 — Address input bit 10 |
| Broche 22 | /OE/VPP — Output enable (active low) / programming voltage |
| Broche 23 | A11 — Address input bit 11 |
| Broche 24 | A9 — Address input bit 9 |
| Broche 25 | A8 — Address input bit 8 |
| Broche 26 | A13 — Address input bit 13 |
| Broche 27 | A14 — Address input bit 14 |
| Broche 28 | NC — Not connected (per JEDEC 27C512 PLCC32 layout) |
| Broche 29 | NC — Not connected |
| Broche 30 | NC — Not connected |
| Broche 31 | NC — Not connected |
| Broche 32 | VCC — Power supply, 5 V |
Applications typiques
27C512-20 convient pour 6 applications: Legacy Embedded Controller Firmware, Arcade Game and Retro-Computing Cartridges, Industrial Equipment BIOS and Boot Code, Development and Prototype Firmware Storage, Telecom and Network Card Configuration Memory, Automotive and Test Equipment Firmware.
Legacy Embedded Controller Firmware
The 27C512-20 stores boot and application firmware in 8-bit microcontroller systems built around 5V buses, where its 64K x 8 organization maps directly to a full 64 KB code space and the 200 ns access time meets classic 5-8 MHz CPU timing without wait states. Plugged into the JEDEC 27C512 socket with /CE tied to address decode and /OE to the CPU read strobe, the device provides deterministic, unalterable code storage. The UV window allows field revision during development, and CMOS standby current keeps idle system power low. Modern maintenance of such systems typically uses faster EPROM or Flash substitutes, but original-grade silicon preserves authentic timing margins.
Recommandé
Arcade Game and Retro-Computing Cartridges
Arcade PCBs and vintage home computers of the 1980s-90s use 27C512 sockets for game code and character ROMs. The 27C512-20's 64K x 8 capacity and 5V parallel interface match these boards exactly, and its ceramic LCC32 package suits surface-mounted or socketed cartridge positions. According to the eharmon EPROM cross-reference, hobbyists commonly mix original EPROMs with W27C512 EEPROM or GLS27SF512 Flash substitutes in these sockets for easier reprogramming during multi-game mod kits. When restoring to factory condition, the -20 grade's 200 ns speed matches original timing on 12 MHz-class 68000 and Z80 buses without introducing wait-state or bus-contention issues.
Recommandé
Industrial Equipment BIOS and Boot Code
PLC controllers, CNC machines, medical devices, and telecom line cards of that era store BIOS, monitor, and diagnostic code in 27C512 sockets. The 27C512-20's non-volatile CMOS EPROM retains code through power cycles and decades of storage, with 3-state outputs permitting multiple memories on a shared 8-bit bus via /CE address decoding. Its 200 ns access time is conservative but adequate for the 4-8 MHz processor clocks typical of such equipment. Because the part is obsolete, service organizations qualifying replacements should verify M27C512 or AT27C512R pin-to-pin equivalence and confirm programming-voltage compatibility of their EPROM programmers before swapping devices.
Recommandé
Development and Prototype Firmware Storage
The ceramic package's ultraviolet window makes the 27C512-20 suitable for iterative firmware development: code is erased with a UV lamp in minutes and reprogrammed, unlike OTP variants which are single-use. The JEDEC pinout lets the same target board accept development EPROMs and production OTP or Flash devices interchangeably. The 200 ns grade supports conventional microprocessor buses of legacy designs, while the single 5V read supply simplifies bench setups - only programming equipment needs the higher VPP. Engineers should verify their programmer supports the CMOS 27C512 algorithm, since NMOS-era algorithms can overstress CMOS dies during programming pulses.
Recommandé
Telecom and Network Card Configuration Memory
Line cards, modems, and network interface boards from the late 1980s and 1990s use 27C512 devices for configuration tables, DSP boot code, and protocol firmware. The 27C512-20's 64K x 8 parallel organization, 5V-only read operation, and 3-state bus outputs integrate directly into these card designs, with the ceramic LCC32 providing a durable, socketed surface-mount option. The 200 ns access time comfortably serves the slower bus cycles of these subsystems. For telephony equipment still in service, replacement strategy matters: ST M27C512 and Microchip AT27C512R remain the lowest-risk drop-ins, while Flash substitutes enable field updates without desoldering.
Recommandé
Automotive and Test Equipment Firmware
Engine control units, diagnostic testers, and bench instruments of the EPROM era hold calibration tables and firmware in 27C512 sockets. The 27C512-20's absolute non-volatility, 5V CMOS read interface, and wide availability during that period made it a default choice, and its 64K x 8 capacity matches the memory map window allocated in typical 8/16-bit controllers. The 200 ns access time suits the modest clock rates of these ECUs and testers. Tune shops modifying such ECUs today commonly install socketed EPROMs or Flash replacements (SST27SF512, W27C512) for repeatable reprogramming of calibration maps during iterative testing.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour 27C512-20 — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | M27C512-20XF1 | AT27C512R-70PU | W27C512-45 | GLS27SF512 |
|---|---|---|---|---|---|
| Package | CQCC32 / LCC32 (ceramic) | PLCC32 - same footprint | DIP28 / PLCC32 family | DIP28 / PLCC32 | DIP28 / PLCC32 |
| Brand | Fujitsu | STMicroelectronics | Microchip Technology | Winbond | Greenliant |
| Organization | 64K x 8 | 64K x 8 | 64K x 8 | 64K x 8 | 64K x 8 |
| Max Access Time | 200 ns | 200 ns | 70 ns (faster) | 45-120 ns (faster) | 70 ns (faster) |
| Supply Voltage | 5 V | 5 V | 5 V read | 5 V read | 5 V read |
| Erase Method | UV (ceramic window) | UV or OTP variant | OTP (PU) / UV window variants | Electrical (EEPROM) | Electrical (Flash) |
| Lifecycle Status | Obsolete | Active / mature | Active | Legacy / surplus | Active |
| In-System Reprogrammable | No (UV lamp required) | No (UV lamp required) | No (OTP/UV only) | Yes (electrical) | Yes (electrical/Flash) |
Principaux différenciateurs
- Authentic Fujitsu silicon for restoration-grade repairs (vs M27C512-20XF1)
- UV-erasable ceramic window allows repeated reuse (vs AT27C512R-70PU)
- Slower 200 ns grade limits use on fast buses (vs W27C512-45)
Notes de conception
Verify the programmer algorithm before programming. CMOS 27C512 devices require different VPP levels and pulse widths than NMOS 27xx EPROMs; using an NMOS algorithm can overstress the CMOS die. Confirm the exact suffix (-20, -20/L, -20/J, -20/K) package and speed options against the Fujitsu datasheet before creating a programming file, and never erase/program the original device in valuable vintage boards - program a known replacement instead, as recommended by EPROM repair guides.
When substituting a faster device (AT27C512R at 45-70 ns, W27C512 at 45 ns) into a board designed for the 200 ns 27C512-20, bus timing generally improves, but check output-enable and chip-enable access timing against the host CPU strobes. On boards with slow address decoding or wait-state logic tuned for 200 ns, faster devices are safe; the reverse substitution (slower in place of fast) requires wait states and is the usual failure mode.
The ceramic LCC32/PLCC32 footprint differs mechanically from DIP28: confirm your board uses the 32-pad PLCC/LCC land pattern with pin 1 at the notched corner matching the JEDEC orientation. For socketed retro-computing applications, use a quality machined-pin PLCC socket to avoid contact-resistance drift. Decouple VCC (pin 32) to GND (pin 14) with a 0.1 uF ceramic capacitor placed within a few millimeters of the package.
Informations de conformité
Part predates RoHS/REACH (obsolete ceramic-package EPROM); no published compliance data found in provided sources.
