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Microchip Technology 25AA128XT-I/ST
- Part No.:
- 25AA128XT-I/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
25AA128XT-I/ST.pdf
- Description:
- IC EEPROM 128KBIT SPI 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,303
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Product details
Overview
25AA128XT-I/ST from Microchip Technology is a 128 Kbit SPI Serial EEPROM with 16,384 × 8-bit organization, 64-byte page size, and industrial temperature range (−40°C to +85°C). It operates from 1.8V–5.5V, supports up to 10 MHz clock at 4.5–5.5V, and delivers 5 µA standby current. It is used for nonvolatile parameter storage in microcontroller-based embedded systems requiring reliable, low-power data retention.
For engineers reviewing the 25AA128XT-I/ST datasheet, 25AA128XT-I/ST pinout, 25AA128XT-I/ST application, or 25AA128XT-I/ST equivalent, key selection criteria include VCC range compatibility (1.8–5.5V), TSSOP-8 package footprint, SPI timing compliance at target voltage/frequency, and hardware write protection via WP pin and STATUS register BP bits.
Technical Context
The 25AA128XT-I/ST implements a standard SPI Mode 0,0 interface with separate SI and SO lines, CS-controlled device selection, and HOLD pin for transaction suspension without reset. Its internal architecture includes an 8-bit instruction register, page latches, and high-voltage generator for EEPROM programming.
It supports byte and page writes (up to 64 bytes within one 64-byte boundary), self-timed internal write cycles (≤5 ms), and configurable block protection (none/1/4/1/2/all array) via BP0/BP1 bits in the nonvolatile STATUS register. Write enable latch (WEL) must be set via WREN before each write operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 128 Kbit (16,384 × 8-bit), sufficient for firmware calibration tables or device configuration data |
| Interface | SPI-compatible serial bus (Mode 0,0), enabling direct connection to MCU SPI peripherals without protocol translation |
| Max Clock Frequency | 10 MHz at VCC ≥ 4.5V - enables fast read/write throughput in power-constrained systems |
| Page Size | 64 bytes - defines maximum contiguous write length without crossing physical boundaries |
| Write Endurance | 1,000,000 erase/write cycles - supports long-term field deployment in logging or counter applications |
| Data Retention | >200 years at 25°C - ensures integrity of stored calibration or security keys over product lifetime |
| Supply Voltage | 1.8V–5.5V - compatible with both 3.3V and 5V logic domains and battery-powered designs |
Pinout & Package
25AA128XT-I/ST is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm pitch, JEDEC MO-153 compliant, and marked "25AA128T-I/ST" on top. The exposed pad is not electrically connected and may be left floating or tied to VSS for thermal enhancement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select Input | Active-low enable; deselecting forces SO into high-impedance to share SPI bus with other devices |
| SO | Serial Data Output | Tri-state output delivering read data on falling SCK edge; high-Z when CS high or HOLD active |
| WP | Write-Protect Pin | Hardware lock for STATUS register nonvolatile bits when WPEN=1; low = protection enabled |
| VSS | Ground Reference | Primary return path for all internal circuits and I/O drivers; must be low-impedance |
| SI | Serial Data Input | Latches instructions, addresses, and write data on rising SCK edge; sampled after CS assertion |
| SCK | Serial Clock Input | Synchronizes all SPI transfers; rising edge clocks input, falling edge updates SO |
| HOLD | Hold Input | Pauses ongoing SPI sequence (e.g., during MCU interrupt servicing); requires SCK low to assert |
| VCC | Supply Voltage | Power rail for core logic and EEPROM array; decoupling capacitor required near pin |
Key Features
| Feature | Design Value |
|---|---|
| Block Write Protection | Configurable via BP0/BP1 bits to protect none, upper 1/4, upper 1/2, or entire memory array - prevents accidental overwrite of critical firmware parameters |
| Hardware Write Protection | WP pin + WPEN bit combination enables system-level physical lockout of STATUS register writes - essential for secure boot configuration |
| Self-Timed Write Cycle | Internal 5 ms max write completion eliminates need for external delay timers or polling overhead in host firmware |
| HOLD Function | Enables mid-transaction pause/resume without retransmission - reduces MCU interrupt latency impact on EEPROM access |
| Low Standby Current | 5 µA at 5.5V/125°C - minimizes quiescent power in always-on sensor nodes or battery-backed systems |
Applications
| Industrial Sensor Calibration Storage | Medical Device Configuration Memory |
|---|---|
Use Scenario: Storing factory-calibrated sensor offset/gain coefficients and linearization tables in programmable logic controllers or environmental monitors. IC Role / Device Role / Timing Role: Nonvolatile parameter store accessed during power-up initialization and runtime correction routines via SPI. Use Value: Enables field-replaceable sensor modules with unique calibration data retained across power cycles and firmware updates. | Use Scenario: Holding user-configurable therapy settings, alarm thresholds, and device ID in portable infusion pumps or diagnostic handhelds. IC Role / Device Role / Timing Role: Secure, tamper-resistant configuration storage with hardware write protection preventing unauthorized setting changes. Use Value: Meets IEC 62304 safety requirements by isolating critical configuration data from main application flash and enabling audit-trail-capable updates. |
| Automotive Body Control Module NVM | Smart Energy Meter Firmware Parameters |
Use Scenario: Saving seat/mirror position presets, lighting profiles, and door lock configurations in AEC-Q100 qualified body control units. IC Role / Device Role / Timing Role: AEC-Q100 Grade 2 (−40°C to +105°C) EEPROM interfacing directly with CAN-connected MCU SPI port. Use Value: Provides automotive-grade reliability and >200-year data retention for infotainment personalization features without MCU internal flash wear-out. | Use Scenario: Storing tariff schedules, metering constants, and communication credentials in ANSI C12.22-compliant smart electricity meters. IC Role / Device Role / Timing Role: Tamper-evident, high-endurance NVM for regulatory-critical parameters updated infrequently but requiring absolute retention over 20+ year deployments. Use Value: Eliminates need for external backup batteries or supercapacitors due to 1M-cycle endurance and ultra-low 5 µA standby draw. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25LC128-I/ST | Requires minimum 2.5V VCC; lacks 1.8V operation; otherwise identical pinout, timing, and feature set | Not suitable for 1.8V logic systems; acceptable where supply is stable ≥2.5V | Select only if system VCC never drops below 2.5V; verify timing margins at actual operating voltage |
| AT25DF041A-SSH-T | 4 Mbit density, quad SPI support, 3.3V-only (2.7–3.6V), no HOLD pin, different command set | Higher density but incompatible interface and voltage; no direct replacement capability | Consider only for new designs needing larger capacity and faster throughput; requires full firmware and layout revision |
Compared with 25LC128-I/ST, the 25AA128XT-I/ST offers broader voltage flexibility (1.8–5.5V vs. 2.5–5.5V), making it preferable in mixed-voltage or battery-depleted scenarios; versus AT25DF041A-SSH-T, it provides pin- and command-compatible drop-in capability for legacy SPI EEPROM designs with lower power and proven qualification.
Availability
25AA128XT-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, automotive body control, and smart energy metering applications requiring stable component supply, long-term lifecycle support, and AEC-Q100-aligned reliability.
Supply support for 25AA128XT-I/ST 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
Microchip Technology Inc. is a leading provider of microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 25AA128XT-I/ST belongs to Microchip's 25XX128 family of SPI Serial EEPROMs, designed specifically for robust, low-power nonvolatile data storage in space-constrained embedded systems across industrial, automotive, and medical markets.
FAQ
What is the maximum clock frequency supported by the 25AA128XT-I/ST at 3.3V operation?
The 25AA128XT-I/ST supports up to 5 MHz at VCC = 2.5V–4.5V, including 3.3V nominal operation. This is specified in Table 1-2 AC Characteristics under FCLK condition "2.5V ≤ Vcc < 4.5V". Exceeding 5 MHz at 3.3V violates timing specifications and may cause read/write failures. The 25AA128XT-I/ST datasheet confirms this limit applies directly to the 25AA128XT-I/ST variant.
Does the 25AA128XT-I/ST support SPI Mode 1,1 or only Mode 0,0?
The 25AA128XT-I/ST supports SPI Mode 0,0 exclusively: CPOL = 0 (clock idle low) and CPHA = 0 (data sampled on first clock edge). Figures 1-2 and 1-3 in the datasheet explicitly show data valid on falling SCK edge for SO and sampling on rising SCK edge for SI. The 25AA128XT-I/ST does not support Mode 1,1 or any other SPI mode variants.
How is write protection implemented on the 25AA128XT-I/ST?
Write protection on the 25AA128XT-I/ST uses two independent mechanisms: (1) software-configurable block protection via BP0/BP1 bits in the STATUS register, and (2) hardware-enforced protection using the WP pin combined with the WPEN bit. When WP is low and WPEN = 1, writes to nonvolatile STATUS bits are blocked. The 25AA128XT-I/ST datasheet details this dual-layer scheme in Section 2.3 and Table 3-2.
What is the purpose of the HOLD pin on the 25AA128XT-I/ST?
The HOLD pin on the 25AA128XT-I/ST suspends an ongoing SPI transaction without resetting the internal state or requiring retransmission. When asserted (low) while SCK is low, SI/SO/SCK enter high-impedance and the device pauses; resuming requires bringing HOLD high while SCK remains low. This allows the host MCU to service higher-priority interrupts. The 25AA128XT-I/ST functional description in Section 2.6 confirms this behavior.
Is the 25AA128XT-I/ST RoHS compliant and AEC-Q100 qualified?
Yes, the 25AA128XT-I/ST is RoHS compliant and AEC-Q100 qualified for the Industrial temperature grade (−40°C to +85°C), as stated in the "Features" section of the datasheet. The "T" suffix in the part number denotes temperature grade, and "I" explicitly indicates Industrial qualification. The 25AA128XT-I/ST meets stress test requirements per AEC-Q100 Rev G for reliability in automotive environments.
25AA128XT-I/ST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 128Kbit
- Memory Organization:
- 16K x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 10 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- -
- Voltage - Supply:
- 1.8V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
25AA128XT-I/ST FAQ
1.How can I place an order for 25AA128XT-I/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 25AA128XT-I/ST 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 25AA128XT-I/ST reliable?
The price and inventory of 25AA128XT-I/ST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25AA128XT-I/ST is usually 5 days.
3.What payment methods are accepted for 25AA128XT-I/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25AA128XT-I/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25AA128XT-I/ST?
25AA128XT-I/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25AA128XT-I/ST 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 25AA128XT-I/ST?
For technical support, including 25AA128XT-I/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25AA128XT-I/ST requirements.
6.How does Aetrix verify that 25AA128XT-I/ST is sourced from the original manufacturer or authorized distributors?
All 25AA128XT-I/ST 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 25AA128XT-I/ST meets industry standards.
7.What is the process for return or replacement of 25AA128XT-I/ST?
All 25AA128XT-I/ST units undergo pre-shipment inspection (PSI). If there is an issue with 25AA128XT-I/ST, 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 25AA128XT-I/ST part is unused and in its original packaging.
Return procedure for 25AA128XT-I/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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