25AA1024T-I/SM - 1Mbit SPI EEPROM 1.8V SOIJ-8 | Microchip
部品番号: 25AA1024T-I/SM ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $3.1 | $3.10 |
| 10 | $2.78 | $27.80 |
| 100 | $2.45 | $245.00 |
| 500 | $2.18 | $1,090.00 |
| 1,000 | $1.92 | $1,920.00 |
25AA1024T-I/SM 概要
A serial EEPROM is a type of non-volatile memory that retains stored data without power and communicates serially over a few wires rather than a parallel bus. EEPROMs occupy the memory hierarchy tier between battery-backed SRAM and Flash: they offer byte-level write granularity (unlike Flash which typically requires page/sector erases), unlimited read cycles, and write endurance of up to 1 million cycles per byte. They are commonly used as parameter, configuration, calibration, and event-log storage in embedded systems.
Key features of the 25AA1024T-I/SM include a 256-byte page write buffer for efficient sequential writes, hardware write-protect (WP), hold pin for pausing serial communication mid-transaction, software write-protection for the upper quarter of memory, and built-in power-on reset (POR) plus write enable latch (WEL). It also supports page, sector (64 KB) and chip erase commands borrowed from Flash for fast bulk clearing, although these are not required for normal byte/page writes.
Internally, the device uses a CMOS EEPROM array with a charge-pump write circuit and an SPI mode 0 and mode 3 compatible interface. Page write time is up to 5 ms with full status polling via the WIP/WEL bits in the STATUS register. Compared to MRAM or FRAM, the 25AA1024 trades write speed for the lowest cost-per-bit and widest ecosystem support in non-volatile storage.
Typical applications include storing user preferences and calibration constants in consumer electronics, asset tracking records in industrial nodes, firmware revision tags in medical devices, and data logging in automotive subsystems. It is well suited to systems that need reliable, low-power, byte-writeable non-volatile storage accessible from a microcontroller via SPI.
When designing with this part, place a 100 nF decoupling capacitor close to VCC, keep SPI traces short, and tie CS, WP and HOLD high through a pull-up resistor when unused to prevent unintended writes. Note that byte writes take up to 5 ms - factor this into your real-time write budget.
This page synthesizes verified distributor pricing, drop-in alternatives, and practical design notes for the 25AA1024T-I/SM beyond what is shown in the manufacturer datasheet.
ドロップイン代替品: 25AA1024T-I/SM — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: 25AA1024T-I/SM （同一形状・フットプリント） — 相違点: Data Retention, Endurance, Interface, Memory Size, Memory Type.
クイック比較ツール — 並列比較する代替部品を選択:
25LC1024T-I/SM
✅ ドロップイン📋 参考代替品（カタログ未掲載）
25AA1024T-E/SM
✅ ドロップイン📋 参考代替品（カタログ未掲載）
25AA1024-I/SM
✅ ドロップイン📋 参考代替品（カタログ未掲載）
25AA512T-I/SM
✅ ドロップイン📋 参考代替品（カタログ未掲載）
25AA1024T-I/MF
✅ ドロップイン📋 参考代替品（カタログ未掲載）
25AA1024T-I/SM 最大定格＆電気的特性
| メモリタイプ | Non-Volatile EEPROM (Serial) |
| メモリサイズ | 1 Mbit (1024 Kbit) |
| Memory Organization | 128K x 8 |
| インターフェース | SPI (Mode 0 and Mode 3) |
| 最大クロック周波数 | 20 MHz |
| Supply Voltage (VCC) | 1.8 V to 5.5 V |
| 動作温度範囲 | -40C to +85C (Industrial) |
| Page Size | 256 bytes |
| Endurance | 1,000,000 write cycles per byte (typical) |
| Data Retention | >200 years |
| パッケージ | 8-pin SOIJ |
| 実装タイプ | Surface Mount |
| Packaging Form | Tape & Reel (T suffix) |
| Write Protection | Hardware WP pin + software quarter-array protect |
| Special Features | Hold pin, POR, WEL, page/sector/chip erase commands |
| RoHS ステータス | Compliant |
25AA1024T-I/SM ピン構成
| ピン 1 | CS — Chip Select input, active low |
| ピン 2 | SO — Serial Data Output (MISO) |
| ピン 3 | WP — Write Protect, active high |
| ピン 4 | VSS — Ground |
| ピン 5 | SI — Serial Data Input (MOSI) |
| ピン 6 | SCK — Serial Clock |
| ピン 7 | HOLD — Hold input, pauses serial communication active low |
| ピン 8 | VCC — Power supply (1.8 V to 5.5 V) |
主な用途
25AA1024T-I/SM の用途: 7 件s: Industrial Sensor Calibration Storage, Consumer Device Settings and Preferences, Medical Device Event and Audit Log, Automotive Subsystem Parameter Storage, Networking and IoT Module Identity Storage, Test and Measurement Data Log Buffers, Display and Lighting Configuration Storage.
Industrial Sensor Calibration Storage
Stores factory calibration constants, sensor trim values, and unit-identity records in industrial sensor nodes. The 25AA1024T-I/SM's 128K x 8 organization accommodates detailed per-channel calibration tables plus user-serviceable calibration history. Operating from 1.8 V to 5.5 V lets the same BOM serve 3.3 V MCU-based and 5 V PLC-based systems; the industrial -40C to +85C window matches process-control cabinet environments. The 1 million-cycle endurance supports frequent in-the-field re-calibration, and the 256-byte page write is fast enough to log a full calibration event in a single SPI transaction.
おすすめ
Consumer Device Settings and Preferences
Persists user preferences, language, last-mode, and network credentials in consumer appliances such as coffee machines, AV receivers, and white goods. The 1 Mbit capacity stores multilingual prompt tables and MAC address plus pairing tokens without external Flash. The 1.8 V lower rail enables single-cell Li-ion or 2x AA battery powered designs. Standby current below 1 uA is critical for battery-backed settings retention, and SPI Mode 0/3 compatibility matches essentially all Cortex-M and AVR controllers used in this segment.
おすすめ
Medical Device Event and Audit Log
Captures immutable audit records of device usage, dose events, or session timestamps in medical instruments, with the 25AA1024T-I/SM acting as a tamper-evident event buffer before offload. The wide -40C to +85C range covers clinical and laboratory environments, and the >200 year data retention ensures long-term forensic traceability. Hardware write-protect (WP) prevents firmware from re-writing critical audit records, while software quarter-array protect reserves the upper 256 Kbit for compliance logs. SPI access lets a co-processor or host MCU append records without bus contention.
おすすめ
Automotive Subsystem Parameter Storage
Provides non-volatile parameter and feature-flag storage for body, HMI, and aftermarket automotive ECUs. Although the 25AA1024T-I/SM itself is not AEC-Q100 qualified, the -40C to +85C industrial rating fits cabin and under-hood-near modules; for AEC-Q100 systems Microchip offers the 25AA1024T-E/SM extended-temperature variant in the same SOIJ-8 footprint. The 1 Mbit density accommodates CAN node configuration tables, mileage counters and seat-position memory. SPI Mode 0/3 bus compatibility aligns with all common automotive microcontrollers.
おすすめ
Networking and IoT Module Identity Storage
Stores MAC address, security keys, device certificates, and provisioning data in Wi-Fi, Bluetooth, and sub-GHz IoT modules. The 25AA1024T-I/SM's 1 Mbit capacity fits full X.509 device certificates plus OEM data, removing the need for a dedicated secure element in cost-sensitive designs. SPI bus up to 20 MHz lets a Cortex-M4 host fetch and verify certificates with negligible latency. Low standby current and 1.8 V operation let the module stay in deep-sleep with credentials intact over months on battery.
おすすめ
Test and Measurement Data Log Buffers
Buffers measurement records and instrument-state between offload cycles in handheld DMMs, oscilloscope probes, and process calibrators. The 25AA1024T-I/SM offers 1 Mbit for tens of thousands of samples, with each 256-byte page supporting efficient batch writes when logging bursts. The wide 1.8 V to 5.5 V supply matches lithium primary cells and USB-powered instruments. The >200 year retention protects logged data even when instruments sit idle in storage, and the hardware WP prevents accidental erasure during instrument power-down.
おすすめ
Display and Lighting Configuration Storage
Stores gamma curves, color-calibration profiles, and lighting scene presets for LED drivers and small TFT/LCD displays. The 25AA1024T-I/SM provides 128 Kbytes of room for full 8-bit-per-pixel gamma tables plus per-channel trim values, all accessible via SPI from the same bus as the LED driver ICs. Industrial temperature rating suits both indoor commercial lighting and outdoor signage enclosures. The HOLD pin allows the display host to pause EEPROM access mid-transaction while the LED driver is updated.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: 25AA1024T-I/SM — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | 25LC1024T-I/SM | 25AA1024T-E/SM | 25AA1024-I/SM | 25AA512T-I/SM | 25AA1024T-I/MF |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SOIJ-8 | SOIJ-8 - same | SOIJ-8 - same | SOIJ-8 - same | SOIJ-8 - same | SOIJ-8 - same |
| Memory Size | 1 Mbit (128K x 8) | 1 Mbit (128K x 8) | 1 Mbit (128K x 8) | 1 Mbit (128K x 8) | 512 Kbit (64K x 8) | 1 Mbit (128K x 8) |
| VCC Range | 1.8 V to 5.5 V | 2.5 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Max SPI Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Temperature Range | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| Packaging Form | Tape & Reel | Tape & Reel | Tape & Reel | Tube | Tape & Reel | Tape & Reel |
| AEC-Q100 Automotive | Not qualified | Not qualified | Not qualified (extended temp) | Not qualified | Not qualified | Not qualified |
| Approx 1k Price (USD) | 1.92 | 1.85 | 2.10 | 2.00 | 1.65 | 1.92 |
主な差別化要因
- Lowest voltage operation in the 1 Mbit SOIJ-8 SPI EEPROM class （vs 25LC1024T-I/SM)
- Industrial -40C to +85C rating with same pinout （vs 25AA1024T-E/SM)
- 1 Mbit density doubles the storage of the next-smaller sibling （vs 25AA512T-I/SM)
設計ノート
Place a 100 nF X7R decoupling capacitor within 5 mm of the VCC pin. The SOIJ-8 pad pattern is identical to standard SOIC-8 - existing 25xxx-series PCB footprints are directly reusable. Keep the CS trace short and route it on an outer layer to minimize capacitive coupling to SCK. For high-noise environments, place a 10 kohm pull-up on CS, WP, and HOLD tied to VCC to prevent spurious writes during MCU reset.
Do not exceed 5.5 V on VCC - the device is not 5 V tolerant in absolute maximum. Always drive CS high after each SPI transaction so the internal state machine can finalize the write. During page writes, do not split the write across two CS low pulses - the internal buffer is cleared when CS goes high, and you will lose the unwritten bytes. Wait at least 5 ms (or poll WIP in the STATUS register) before initiating another write.
The SPI bus can run up to 20 MHz but only if traces are short (under 50 mm) and the bus is not loaded by many secondaries. For bus lengths beyond 100 mm, lower SCK to 10 MHz or add a 33 ohm series resistor near the master to dampen reflections. The HOLD pin allows the master to pause an in-flight read or write without deselecting the chip - useful when an interrupt preempts the SPI transfer.
Read current is typically 5 mA at 20 MHz and standby current is below 1 uA per the Microchip datasheet. The part is rated to operate from 1.8 V to 5.5 V - this is wider than the 2.5 V lower limit of the 25LC1024T variant. For battery-backed applications, disable the SPI clock and raise CS high to put the part in standby. There is no dedicated power-down pin; standby is purely SPI-state driven.
コンプライアンス情報
RoHS compliant per Microchip product page. Not AEC-Q100 qualified; for AEC-Q100 designs use the automotive-qualified variants per the latest Microchip cross-reference. Halogen-free status not explicitly listed in the verified web data.
