25LC512-E/SN - 512Kbit SPI EEPROM, 20MHz, 2.5-5.5V | Microchip
MPN: 25LC512-E/SN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.65 | $1.65 |
| 10 | $1.48 | $14.80 |
| 100 | $1.21 | $121.00 |
| 500 | $1.02 | $510.00 |
| 1,000 | $0.86 | $860.00 |
25LC512-E/SN Overview
What is a Serial EEPROM? A serial EEPROM is a type of non-volatile memory (NVM) that retains data without power and communicates over a low-pin-count serial bus (SPI, I2C, or Microwire). Within the memory hierarchy, EEPROMs sit below Flash for write endurance (typically 1M cycles per byte/page) but offer byte-level granularity, eliminating the sector-erase overhead of Flash. The 25LC512 family belongs to the broader category of memory ICs, specifically byte-alterable non-volatile storage used for configuration, calibration, and event-log retention.
Key features include page, sector, and chip erase functions typically found in Flash products - these are not required for normal byte/page writes. The device offers a 128-byte page write buffer, hardware and software write protection via the /WP and /HOLD pins, and a status register flag for write-cycle completion. Self-timed erase and write cycles complete in 5 ms maximum, and an additional 128-byte page mode allows efficient sequential writes.
The 25LC512 uses a CMOS process with on-chip latching to support SPI Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1), giving it compatibility with virtually any microcontroller SPI peripheral. Typical active read current is around 5 mA at 5V/20 MHz, with standby current under 1 uA, enabling low-power sleep-mode data retention designs.
Typical applications include consumer-electronics configuration storage (TV backlight calibration, white-balance tables, MAC address backup), industrial sensor calibration constants, medical-device patient-log retention, and automotive accessory parameter storage. The wide voltage range also enables direct 3.3V MCU interfacing without level shifters.
When designing with this device, keep /CS low during a full read or write sequence and respect the 5 ms write-cycle time before polling the status register. For high-reliability applications, plan for wear-leveling because each byte/page supports up to 1 million erase/write cycles. Use external pull-ups on /WP and /HOLD if those pins are tied high in the layout.
This page synthesizes distributor pricing, drop-in alternative MPNs, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for 25LC512-E/SN — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with 25LC512-E/SN (same form factor and footprint) — differing in Data Retention, Interface, Memory Type, Page Size, Endurance.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
25LC512-I/SN
✅ Drop-In✓ In Stock
$1.36 / Unit
View Datasheet →25LC512T-E/SN
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →25LC512-E/SM
✅ Drop-In📋 Reference alternative (not in catalog)
25LC512-M/SN
✅ Drop-In📋 Reference alternative (not in catalog)
25AA512-I/SN
✅ Drop-In📋 Reference alternative (not in catalog)
AT25512-SS
✅ Drop-In📋 Reference alternative (not in catalog)
25LC512-E/SN Maximum Ratings & Electrical Characteristics
| Memory Type | Non-volatile EEPROM (Electrically Erasable Programmable Read-Only Memory) |
| Memory Size | 512 Kbit (64K x 8) |
| Organization | 64K x 8 (single block) |
| Interface | SPI (Serial Peripheral Interface) - Modes 0 and 3, 3-wire optional |
| Maximum Clock Frequency | 20 MHz |
| Supply Voltage (Vcc) | 2.5 V to 5.5 V |
| Operating Temperature Range (E suffix) | -40 C to +125 C |
| Page Size | 128 bytes |
| Byte Write Time | 5 ms (max) |
| Page Write Time | 5 ms (max) |
| Endurance | 1,000,000 erase/write cycles per byte (typical) |
| Data Retention | 200 years (typical) |
| Active Read Current | 5 mA (typical at 5 V, 20 MHz) |
| Standby Current | 1 uA (max) |
| Write Protection | Hardware (/WP pin) and software (status register bits) |
| Package | 8-SOIC (SN, 0.154" / 3.90 mm body width) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (unlimited floor life at <=30 C / 85% RH) |
| RoHS Status | Compliant |
25LC512-E/SN Pin Configuration
| Pin 1 | /CS — Chip Select, active low. Enables SPI communication when pulled low. |
| Pin 2 | SO — Serial Data Out. Drives read data from the EEPROM to the MCU. |
| Pin 3 | /WP — Write Protect, active low. When low, blocks write operations to the array. |
| Pin 4 | VSS — Ground reference. |
| Pin 5 | SI — Serial Data In. Receives opcode, address, and write data from the MCU. |
| Pin 6 | SCK — Serial Clock. Driven by the MCU to clock data on SI and SO. |
| Pin 7 | /HOLD — Hold, active low. Pauses a serial communication without deselecting the device. |
| Pin 8 | VCC — Power supply input, 2.5 V to 5.5 V. |
Typical Applications
25LC512-E/SN is suitable for 6 applications: Consumer Electronics Configuration Storage, Industrial Sensor Calibration Storage, Medical Device Patient Log Retention, Automotive Accessory Parameter Storage, IoT Smart-Home Device Configuration, Test & Measurement Instrument Calibration.
Consumer Electronics Configuration Storage
The 25LC512-E/SN is widely used for storing user-tunable parameters in consumer devices such as TV backlight calibration curves, audio equalizer presets, and MAC address backup. Its 512 Kbit (64K x 8) density provides ample room for multi-region factory profiles and field-updatable firmware settings. The 20 MHz SPI clock at 5 V enables fast boot-time data load, while the 1 uA standby current preserves battery life in standby modes. The wide 2.5-5.5 V supply range allows direct connection to 3.3 V system-on-chips without level translation, and the 1 million cycle endurance supports frequent user-save operations throughout the device lifetime.
Recommended
Industrial Sensor Calibration Storage
Industrial pressure, flow, and temperature sensors use the 25LC512-E/SN to retain factory calibration coefficients and linearization tables. The -40 C to +125 C extended operating range handles harsh factory-floor and outdoor environments, while the 200-year data retention guarantees calibration integrity over the equipment lifetime. Each calibration point can be updated individually using the byte write command without disturbing adjacent data. The status register's WIP and WEL flags enable deterministic polling from a host MCU during time-critical acquisitions, and the hardware /WP pin lets maintenance technicians lock calibration against accidental overwrite.
Recommended
Medical Device Patient Log Retention
Patient-monitoring equipment such as infusion pumps and portable dialysis machines use the 25LC512-E/SN for non-volatile event-log storage. The 200-year data retention and 1 million cycle endurance exceed medical-device reliability requirements, ensuring logged therapy events remain intact across power cycles and battery replacement. Byte-level write granularity lets the firmware append a single log entry without erasing the whole array, simplifying firmware and reducing write-cycle overhead. SPI Mode 0/3 support enables use with virtually any medical-grade MCU, while the 8-SOIC footprint simplifies PCB layout in space-constrained handheld designs.
Recommended
Automotive Accessory Parameter Storage
Aftermarket automotive accessories such as gauge clusters, infotainment modules, and body-control retrofits use the 25LC512-E/SN to store vehicle-specific configuration (tire-pressure thresholds, audio EQ, gear ratios). The -40 C to +125 C operating range survives under-dash and under-hood thermal environments, while the SPI interface is naturally immune to the EMI common in automotive wiring harnesses. The 128-byte page write completes in 5 ms, fast enough to commit configuration changes during ignition-off routines without user-perceived delay. For designs needing the same density on an I2C bus, the 24LC512T-I/SM is a directly comparable alternative.
Recommended
IoT Smart-Home Device Configuration
Smart thermostats, smart locks, and connected lighting controllers use the 25LC512-E/SN to persist Wi-Fi credentials, schedule tables, and user preferences. The 1 uA standby current extends battery life in wireless sensors that wake only when transmitting, and the 2.5-5.5 V supply range supports both battery (1S Li-ion) and USB-powered (5 V) designs. The 8-SOIC footprint is reflow-compatible with standard lead-free profiles, simplifying high-volume manufacturing. The 20 MHz SPI clock at 5 V allows the host MCU to load the entire 64 KB configuration array in approximately 26 ms at full bus utilization.
Recommended
Test & Measurement Instrument Calibration
Bench multimeters, oscilloscopes, and data-acquisition modules use the 25LC512-E/SN to store per-range calibration coefficients and operator preference (display units, beep volume, last-used mode). The 200-year data retention preserves NIST-traceable calibration across the instrument's calibration interval, while the byte-write granularity lets the firmware apply single-point corrections without erasing neighboring data. The 5 ms page-write cycle time is fast enough for in-system calibration without operator wait, and the hardware /WP pin allows a rear-panel toggle to lock calibration against accidental field-erase.
Recommended
Recommended Products Summary
Engineering reference data for 25LC512-E/SN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 25LC512-I/SN | 25LC512T-E/SN | 25LC512-E/SM | 25LC512-M/SN | AT25512-SS |
|---|---|---|---|---|---|---|
| Package | 8-SOIC (SN, 0.154") | 8-SOIC (SN) - same | 8-SOIC (SN) - same | 8-SOIC (SM, 0.208") - wider | 8-SOIC (SN) - same | 8-SOIC (SS, ~208 px) - same footprint |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology (ex-Atmel) |
| Memory Size | 512 Kbit (64K x 8) | 512 Kbit | 512 Kbit | 512 Kbit | 512 Kbit | 512 Kbit |
| Max SPI Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| Operating Temperature | -40 C to +125 C | -40 C to +85 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +85 C |
| Endurance (cycles) | 1,000,000 | 1,000,000 | 1,000,000 | 1,000,000 | 1,000,000 | 1,000,000 |
| Write Protection | /WP pin + SRW | /WP pin + SRW | /WP pin + SRW | /WP pin + SRW | /WP pin + SRW | /WP pin |
| Packaging Format | Tube | Tube | Tape & Reel | Tube | Tube | Tube |
Key Differentiators
- Highest temperature grade in the 25LC512 SOIC family (vs 25LC512-I/SN)
- 20 MHz SPI throughput at full 5 V supply (vs 25AA512-I/SN)
- Single-block 64K x 8 organization simplifies firmware pointer math (vs AT25512-SS)
Design Notes
SPI bus integrity at 20 MHz requires careful PCB layout. Keep the SCK trace short (under 50 mm), place a 10 kohm pull-up on /CS to prevent spurious writes, and add 100 ohm series resistors on SCK/SO/SI if the bus runs longer than 75 mm. The /HOLD and /WP pins should also be pulled up to Vcc with 10 kohm resistors when not actively driven, otherwise floating inputs can inject noise and cause unintended write-protect or hold assertions.
Always respect the 5 ms write-cycle time before polling the WIP bit. If the firmware writes a byte then immediately re-selects the chip and reads the same address, the read will return stale or undefined data because the internal write is still in progress. The recommended pattern is: (1) issue the WRITE opcode + address + data, (2) pull /CS HIGH, (3) wait at least 5 ms, (4) optionally issue RDSR and poll until WIP=0. Skipping the wait is the single most common source of EEPROM data-corruption bugs.
Decouple Vcc with a 100 nF X7R ceramic capacitor placed within 3 mm of pin 8, plus a 4.7 uF bulk tantalum or ceramic cap on the same rail. The 25LC512 draws sharp 5 mA current pulses during SPI read bursts, and inadequate decoupling can cause Vcc droop that resets internal state. Place the EEPROM away from high-current switching nodes (DC-DC converters, motor drivers) by at least 20 mm to minimize EMI-induced write corruption. A small ground plane under the SOIC-8 footprint reduces radiated emissions from the SPI clock edge.
Estimated: average active current during 20 MHz read bursts is approximately 5 mA at 5 V (25 mW). For a sensor node that reads 64 KB once per minute and sleeps otherwise, the time-averaged EEPROM contribution is under 1 uA. In a battery-powered design, the dominant energy cost is the 5 ms write cycle at ~3 mA active (15 uC per write), so the firmware should batch configuration changes into single 128-byte page writes whenever possible to minimize total write time and battery drain.
Compliance Information
RoHS and REACH compliant per Microchip product page. The -E temperature grade is industrial/extended but not AEC-Q100 qualified; for AEC-Q100, select the 25LC512-E/SN VAO automotive variant. Halogen-free per Microchip environmental compliance documentation.
