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Microchip Technology 25C040XT/ST
- Part No.:
- 25C040XT/ST
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
25C040XT/ST.pdf
- Description:
- IC EEPROM 4KBIT SPI 3MHZ 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,677
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Product details
Overview
25C040XT/ST from Microchip Technology Inc. is a 4 Kbit (512 × 8) SPI-compatible serial EEPROM designed for nonvolatile data storage in automotive and industrial systems operating from 4.5V to 5.5V. It delivers 3 MHz max clock frequency, 5 ms max write cycle time, 1 million endurance cycles, and supports -40°C to +125°C operation. Its integrated HOLD and WP pins enable robust system-level control in engine control units and battery management.
For engineers reviewing the 25C040XT/ST datasheet, 25C040XT/ST pinout, 25C040XT/ST application, or 25C040XT/ST equivalent, this page provides verified functional specifications, validated TSSOP-8 pin mapping, confirmed automotive-grade temperature compliance, and two technically documented alternative parts for design continuity.
Technical Context
The 25C040XT/ST implements a standard SPI Mode 0,0 interface with separate SI and SO lines, requiring CS, SCK, SI, SO, WP, HOLD, VCC, and VSS. It uses an internal high-voltage generator for EEPROM programming and features a status register with WIP, WEL, BP0, and BP1 bits for real-time write monitoring and block protection configuration.
Its architecture supports sequential read, byte/page write (16-byte pages), and hardware-based write protection via both WP pin and STATUS register settings. The device enters Standby mode when CS is high, drawing only 500 nA typical current, and resumes communication without sequence reset after HOLD deassertion.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 4 Kbit (512 × 8-bit array) - fixed address space supporting up to 512 unique byte locations |
| Interface | SPI Mode 0,0 - compatible with standard microcontroller SPI peripherals without mode translation logic |
| Max clock frequency | 3 MHz at VCC = 4.5–5.5V - enables fast read/write transfers in time-critical automotive subsystems |
| Write cycle time | 5 ms maximum - defines minimum interval between successive write operations; self-timed, no external delay required |
| Endurance | 1 million erase/write cycles - ensures long-term reliability in logging or calibration data storage applications |
| Data retention | Over 200 years - guarantees nonvolatile data integrity across full automotive lifecycle without refresh |
| Operating temperature | -40°C to +125°C - qualified for under-hood and powertrain environments per AEC-Q100 stress requirements |
Pinout & Package
25C040XT/ST is supplied in an 8-pin Thin Shrink Small Outline Package (TSSOP-8), 4.4 mm body width, with lead pitch of 0.65 mm and JEDEC MO-179 compliant footprint. Pin 1 is marked by a dot or beveled corner; pin numbering follows standard counter-clockwise convention from top-left.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | HOLD | Active-low suspend signal - pauses ongoing SPI transfer without resetting internal address pointer; tri-states SO during hold |
| 2 | VCC | Positive supply input - requires stable 4.5–5.5V; powers internal HV generator and logic; decoupling capacitor mandatory |
| 3 | CS | Chip Select - active-low enable; must be low for all SPI transactions; rising edge initiates internal write cycle |
| 4 | SO | Serial Output - tri-state open-drain output; drives data on falling SCK edge; shares bus with other SPI slaves |
| 5 | WP | Write-Protect - hardware lock; low disables all writes to memory and STATUS register regardless of WEL state |
| 6 | VSS | Ground reference - return path for all currents; must be connected directly to system ground plane |
| 7 | SI | Serial Input - latches instruction, address, and data on rising SCK edge; driven by master MCU SPI MOSI line |
| 8 | SCK | Serial Clock - synchronous timing reference; master-generated; rising edge clocks SI, falling edge updates SO |
Key Features
| Feature | Design Value |
|---|---|
| Automotive temperature grade | Qualified for -40°C to +125°C operation - meets AEC-Q100 stress test requirements for engine control modules |
| Hardware write protection | Dual-layer protection: WP pin + STATUS register BP0/BP1 bits - prevents accidental overwrites in safety-critical firmware storage |
| Page write capability | 16-byte page buffer - reduces SPI transaction count by up to 16× vs. byte-write, improving system throughput and reducing bus occupancy |
| Low-power standby | 500 nA typical ICCS - minimizes quiescent current in always-on vehicle subsystems such as telematics or gateway ECUs |
| HOLD function | Non-disruptive pause/resume - allows host MCU to service higher-priority interrupts without losing SPI context or reinitializing sequence |
Applications
| Engine Control Unit (ECU) | Advanced Driver Assistance Systems (ADAS) |
|---|---|
Use Scenario: Storing calibration parameters, fault codes, and adaptive learning values that persist across ignition cycles. IC Role / Device Role / Timing Role: Nonvolatile configuration storage with guaranteed data integrity under voltage transients and thermal stress. Use Value: Enables zero-latency parameter recall at startup and supports ISO 26262 ASIL-B diagnostic data retention requirements. |
Use Scenario: Logging sensor fusion metadata, camera calibration offsets, and radar echo profiles for post-crash analysis. IC Role / Device Role / Timing Role: High-reliability event-triggered data capture with deterministic 5 ms write latency. Use Value: Provides tamper-resistant, long-retention storage for regulatory compliance and functional safety traceability. |
| Electric Vehicle Battery Management System (BMS) | Industrial Motor Drive Controller |
Use Scenario: Recording cell voltage history, thermal derating thresholds, and charge cycle counters across 10+ years of service life. IC Role / Device Role / Timing Role: Automotive-grade EEPROM interfacing directly with BMS MCU via SPI, surviving repeated thermal cycling. Use Value: Delivers >200-year data retention and 1M-cycle endurance needed for lifetime battery health analytics. |
Use Scenario: Holding motor tuning parameters, encoder zero-point offsets, and safety shutdown logs in factory automation drives. IC Role / Device Role / Timing Role: Robust configuration memory co-located with motor control ASIC, immune to ESD and conducted noise. Use Value: Ensures consistent performance across maintenance intervals and eliminates field recalibration due to data corruption. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25C040T | Same die, PDIP/SOIC package; no alternate pinout; rated for same 4.5–5.5V, -40°C to +125°C range | Preferred for through-hole or standard SOIC PCB layouts; lacks TSSOP-8 space-saving footprint | Select 25C040T when legacy board layout or manual assembly requires larger package form factor. |
| 25AA040AT | 1.8–5.5V VCC range; 1 MHz max clock; -40°C to +85°C; newer revision with enhanced ESD (>6 kV) | Broader voltage compatibility but lower speed and temperature rating; not automotive-qualified | Choose 25AA040AT only for cost-sensitive industrial or consumer designs where extended temp range is unnecessary. |
Compared with 25C040XT/ST, 25C040T offers identical electrical and thermal specs in legacy packages, while 25AA040AT trades automotive qualification and speed for wider VCC flexibility and improved ESD robustness-making it unsuitable for under-hood deployment but viable for board-level non-automotive use.
Availability
25C040XT/ST is available at Aetrix Electronics and suitable for automotive powertrain control, ADAS data logging, and industrial motor drive applications requiring stable component supply across extended product lifecycles.
Supply support for 25C040XT/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 U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and memory products for embedded control applications.
The 25C040XT/ST belongs to Microchip's automotive-grade serial EEPROM product line, engineered specifically for reliable nonvolatile storage in harsh-temperature, high-reliability systems like engine controllers and battery management units.
FAQ
What is the maximum clock frequency supported by the 25C040XT/ST?
The 25C040XT/ST supports a maximum clock frequency of 3 MHz when operated within its specified VCC range of 4.5V to 5.5V and temperature range of -40°C to +125°C. This value is explicitly defined in Table 1-2 of the DS21204E datasheet under "FCLK" for VCC = 4.5V to 5.5V. Operation above this frequency may result in unreliable communication or data corruption. The 25C040XT/ST must be configured for SPI Mode 0,0 to ensure timing compliance.
Does the 25C040XT/ST support page write operations, and what is the page size?
Yes, the 25C040XT/ST supports page write operations with a fixed page size of 16 bytes. This allows up to 16 consecutive bytes to be loaded into the internal write buffer before initiating the internal 5 ms write cycle. Page boundaries align to addresses ending in 0x00–0x0F, and crossing a boundary during a page write causes rollover to the start of the same page. This capability is confirmed in the "Features" section and functional description of DS21204E, and directly impacts system-level SPI efficiency when writing configuration blocks.
How does the HOLD pin function during an active SPI transaction on the 25C040XT/ST?
The HOLD pin on the 25C040XT/ST suspends SPI communication mid-sequence without resetting the internal address pointer or requiring retransmission. When pulled low while SCK is low, SI, SCK, and SO enter high-impedance states and all inputs except CS are ignored. To resume, HOLD must be raised while SCK remains low. This behavior is fully documented in Section 2.6 and Figure 1-1 of DS21204E and enables deterministic interrupt handling in real-time automotive MCUs using the 25C040XT/ST.
What are the valid voltage and temperature ranges for the 25C040XT/ST?
The 25C040XT/ST is specified for VCC = 4.5V to 5.5V and operating temperature = -40°C to +125°C. These limits are exclusive to the 25C040 variant (as shown in the Device Selection Table on page 1 of DS21204E) and distinguish it from the 25AA040 (1.8–5.5V, I-temp) and 25LC040 (2.5–5.5V, I-temp). Exceeding these ranges invalidates parametric guarantees including write cycle time, endurance, and data retention. The "E" suffix in part marking confirms automotive temperature qualification.
Is the 25C040XT/ST pin-compatible with other members of the 25XX040 family in TSSOP-8 package?
No-the 25C040XT/ST uses an alternate pinout specific to the "X" and "XT" suffix variants in TSSOP-8, as noted in the Product Identification System (page 19 of DS21204E). While standard 25C040T uses conventional pin mapping (CS=1, SO=2, WP=3, etc.), the XT/ST variant swaps HOLD and VCC positions. This alternate pinout is incompatible with standard 25C040T layouts and requires dedicated PCB footprint design. Always verify pin assignment using Table 2-1 and package drawings in DS21204E before layout.
25C040XT/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:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 4Kbit
- Memory Organization:
- 512 x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 3 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
25C040XT/ST FAQ
1.How can I place an order for 25C040XT/ST through Aetrix?
Please submit a Request for Quotation (RFQ) for 25C040XT/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 25C040XT/ST reliable?
The price and inventory of 25C040XT/ST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25C040XT/ST is usually 5 days.
3.What payment methods are accepted for 25C040XT/ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25C040XT/ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25C040XT/ST?
25C040XT/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25C040XT/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 25C040XT/ST?
For technical support, including 25C040XT/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25C040XT/ST requirements.
6.How does Aetrix verify that 25C040XT/ST is sourced from the original manufacturer or authorized distributors?
All 25C040XT/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 25C040XT/ST meets industry standards.
7.What is the process for return or replacement of 25C040XT/ST?
All 25C040XT/ST units undergo pre-shipment inspection (PSI). If there is an issue with 25C040XT/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 25C040XT/ST part is unused and in its original packaging.
Return procedure for 25C040XT/ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
25C040XT/ST Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
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