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Microchip Technology 25LC040AT-E/OT16KVAO
- Part No.:
- 25LC040AT-E/OT16KVAO
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- SOT-23-6
- Datasheet:
-
25LC040AT-E/OT16KVAO.pdf
- Description:
- IC EEPROM 4KBIT SPI SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:4,448
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Product details
Overview
25LC040AT-E/OT16KVAO from Microchip Technology Inc. is a 4 Kbit (512 × 8) SPI-compatible serial EEPROM with 16-byte page write capability, 10 MHz max clock frequency at 4.5–5.5 V, and automotive-grade temperature support (−40°C to +125°C). It features hardware write protection via WP pin, HOLD input for bus pause, and block-level write protection (none/¼/½/all array). Used in engine control units, ADAS sensor calibration storage, and automotive infotainment firmware parameter retention.
For engineers reviewing the 25LC040AT-E/OT16KVAO datasheet, 25LC040AT-E/OT16KVAO pinout, 25LC040AT-E/OT16KVAO application, or 25LC040AT-E/OT16KVAO equivalent, key selection criteria include automotive temp grade, SOT-23-6 package footprint, SPI timing compliance at 2.5–5.5 V, and nonvolatile data retention exceeding 200 years.
Technical Context
The 25LC040AT-E/OT16KVAO implements a standard SPI Mode 0,0 interface with separate SI/SO lines and CS-controlled device selection. Its internal architecture includes a 512-byte EEPROM array, page latches, HV generator, and STATUS register with WIP/WEL/BP0/BP1 bits for real-time write status and configurable block protection.
Write operations require explicit WREN instruction followed by CS high to initiate self-timed internal write cycle (≤5 ms), while HOLD suspends ongoing transfers without resetting sequence state. The WP pin provides hardware-level write inhibition independent of STATUS register settings, and all inputs feature ±1 µA leakage and 4 kV ESD protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 4 Kbit (512 × 8-bit array), sufficient for boot configuration, calibration coefficients, or small firmware patches |
| Interface | SPI-compatible serial bus (Mode 0,0), compatible with PIC® and most MCU SPI peripherals without bit-banging |
| Max Clock Frequency | 10 MHz at VCC ≥ 4.5 V - enables fast read/write in high-throughput automotive diagnostics |
| Page Write Size | 16 bytes per page - constrains firmware update logic to avoid crossing 16-byte boundaries |
| Endurance | 1,000,000 erase/write cycles - supports frequent logging or runtime parameter updates over vehicle lifetime |
| Data Retention | >200 years at 25°C - ensures long-term reliability for safety-critical stored values without refresh |
| Operating Temp | −40°C to +125°C (Automotive E grade) - qualified for under-hood and powertrain applications |
| VCC Range | 2.5 V to 5.5 V - interoperable with 3.3 V and 5 V automotive subsystems |
Pinout & Package
25LC040AT-E/OT16KVAO uses the 6-lead SOT-23 package (package code OT), with pin 1 marked by laser dot. Pin 1 = VDD, pin 2 = CS, pin 3 = SO, pin 4 = SCK, pin 5 = SI, pin 6 = GND. No exposed pad; no thermal pad connection required.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD (Pin 1) | Supply Voltage Input | Accepts 2.5–5.5 V; powers internal logic and HV generator; decoupling capacitor required near pin |
| CS (Pin 2) | Chip Select Input | Active-low enable; must go high after final data bit to trigger internal write cycle; deselects SO to high-Z |
| SO (Pin 3) | Serial Data Output | Tri-state output; data valid on falling edge of SCK; high-Z when CS high or HOLD low |
| SCK (Pin 4) | Serial Clock Input | Master-generated clock; rising edge latches SI, falling edge updates SO; max 10 MHz at 4.5–5.5 V |
| SI (Pin 5) | Serial Data Input | Latches instruction/address/data on rising SCK edge; accepts 8-bit opcodes (READ/WRITE/WREN/RDSR/etc.) |
| GND (Pin 6) | Ground Reference | Return path for VDD and all I/O; must be low-impedance connection to system ground plane |
Key Features
| Feature | Design Value |
|---|---|
| Hardware Write Protection | WP pin (not present on SOT-23-6 variant per DS21827H-page 13 table) - but 25LC040AT-E/OT16KVAO omits WP; write protection relies solely on STATUS register BP0/BP1 bits |
| HOLD Functionality | HOLD pin absent in SOT-23-6 (pin 7 not allocated); therefore 25LC040AT-E/OT16KVAO does not support bus hold - full SPI transaction must complete uninterrupted |
| Block Write Protection | BP0/BP1 bits in STATUS register enable software-selectable protection of none, upper 1/4 (180h–1FFh), upper 1/2 (100h–1FFh), or entire array (000h–1FFh) |
| Power-On Default State | Write enable latch reset, SO in high-Z, device in Standby - prevents spurious writes during power ramp |
| Low-Power Operation | Standby current ≤1 µA at 2.5 V and +85°C - suitable for always-on automotive modules with strict quiescent current budgets |
Applications
| Engine Control Unit (ECU) Calibration Storage | Advanced Driver Assistance Systems (ADAS) Sensor Trim |
|---|---|
Use Scenario: Storing fuel map coefficients, ignition timing offsets, and OBD-II diagnostic flags that must survive vehicle battery disconnect. IC Role / Device Role / Timing Role: Nonvolatile parameter store accessed via SPI during ECU boot and runtime calibration updates. Use Value: 200+ year data retention and 1M endurance ensure calibration integrity across 15+ year vehicle service life without refresh. | Use Scenario: Holding camera lens focus offset, radar antenna phase trim, and ultrasonic sensor gain calibration in parking assist systems. IC Role / Device Role / Timing Role: SPI-configurable memory for factory and dealer-level sensor alignment data, written once per vehicle build or service event. Use Value: Automotive temperature grade (−40°C to +125°C) guarantees operation inside sealed ADAS housings exposed to direct sunlight or cold soak. |
| Infotainment System UI Configuration | Body Control Module (BCM) User Preference Memory |
Use Scenario: Saving display brightness, audio equalizer presets, language selection, and Bluetooth pairing history across ignition cycles. IC Role / Device Role / Timing Role: Low-latency SPI EEPROM interfaced directly to infotainment SoC's SPI controller for rapid UI state recall. Use Value: 10 MHz max clock enables sub-100 µs read access to 16-byte UI config blocks, eliminating perceptible UI lag on startup. | Use Scenario: Retaining driver seat position, mirror angle, window auto-up/down settings, and lighting profiles across power cycles. IC Role / Device Role / Timing Role: Dedicated nonvolatile memory for BCM microcontroller to persist user preferences without burdening main flash. Use Value: SOT-23-6 footprint minimizes PCB area in space-constrained BCM modules while supporting 2.5–5.5 V supply range of 12 V automotive systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 25LC040AT-I/OT | Industrial temp grade (−40°C to +85°C); identical pinout, timing, and memory organization | Not qualified for under-hood or powertrain use; limited to cabin modules only | Select only if operating ambient stays below +85°C and automotive qualification is unnecessary |
| AT25040B-SSHL-T | Same 4 Kbit SPI EEPROM, 16-byte page, but AEC-Q100 Grade 2 (−40°C to +105°C); different pinout (SOIC-8) | Requires PCB redesign due to 8-lead SOIC vs. SOT-23-6; higher temp ceiling than industrial but lower than E grade | Choose when AEC-Q100 validation is mandatory and board layout allows SOIC-8 footprint |
Compared with 25LC040AT-I/OT and AT25040B-SSHL-T, the 25LC040AT-E/OT16KVAO uniquely delivers full automotive E-grade qualification (−40°C to +125°C) in the ultra-compact SOT-23-6 package, enabling placement in thermally demanding locations without layout penalty.
Availability
25LC040AT-E/OT16KVAO is available at Aetrix Electronics and suitable for engine control units, ADAS sensor calibration, and automotive infotainment systems requiring stable component supply across extended production lifecycles.
Supply support for 25LC040AT-E/OT16KVAO 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 devices, and memory solutions, headquartered in Chandler, Arizona, with global manufacturing and support infrastructure.
The 25LC040A product line delivers SPI serial EEPROMs optimized for automotive, industrial, and consumer applications requiring reliable, low-power, and pin-efficient nonvolatile storage.
FAQ
What is the operating voltage range for the 25LC040AT-E/OT16KVAO?
The 25LC040AT-E/OT16KVAO operates from 2.5 V to 5.5 V DC. This range supports both 3.3 V and 5 V automotive subsystems, including body control modules and infotainment head units. At 2.5 V, maximum clock frequency is reduced to 5 MHz; full 10 MHz operation requires VCC ≥ 4.5 V per DS21827H Table 1-2.
Does the 25LC040AT-E/OT16KVAO include a HOLD pin in its SOT-23-6 package?
No, the 25LC040AT-E/OT16KVAO in SOT-23-6 (package code OT) does not include a HOLD pin. As confirmed in DS21827H-page 13 Pin Function Table, HOLD is omitted in the 6-lead SOT-23 variant. Bus pause functionality is unavailable; SPI transactions must complete without interruption.
How many write/erase cycles can the 25LC040AT-E/OT16KVAO endure?
The 25LC040AT-E/OT16KVAO guarantees 1,000,000 erase/write cycles at 25°C and VCC = 5.5 V. This endurance rating applies to both byte and page writes. Real-world wear leveling is not implemented; application firmware must manage write distribution if cycling exceeds typical usage patterns.
What package type is used by the 25LC040AT-E/OT16KVAO?
The 25LC040AT-E/OT16KVAO uses the 6-lead SOT-23 package (JEDEC MO-178AA), with pin 1 identified by a laser mark. Dimensions are 2.9 mm × 1.6 mm × 1.1 mm (L × W × H), and it contains no exposed thermal pad. This compact footprint is ideal for space-constrained automotive modules.
Is hardware write protection (WP pin) available on the 25LC040AT-E/OT16KVAO?
No, the WP pin is not present on the SOT-23-6 package of the 25LC040AT-E/OT16KVAO, as shown in DS21827H-page 13 Pin Function Table (WP column shows "-" for OT). Write protection is implemented exclusively via the STATUS register BP0/BP1 bits, configured using the WRSR instruction.
25LC040AT-E/OT16KVAO Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SOT-23-6
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 10 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- -
- Voltage - Supply:
- 2.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-6
25LC040AT-E/OT16KVAO FAQ
1.How can I place an order for 25LC040AT-E/OT16KVAO through Aetrix?
Please submit a Request for Quotation (RFQ) for 25LC040AT-E/OT16KVAO 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 25LC040AT-E/OT16KVAO reliable?
The price and inventory of 25LC040AT-E/OT16KVAO are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25LC040AT-E/OT16KVAO is usually 5 days.
3.What payment methods are accepted for 25LC040AT-E/OT16KVAO?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25LC040AT-E/OT16KVAO transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25LC040AT-E/OT16KVAO?
25LC040AT-E/OT16KVAO orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25LC040AT-E/OT16KVAO 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 25LC040AT-E/OT16KVAO?
For technical support, including 25LC040AT-E/OT16KVAO datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25LC040AT-E/OT16KVAO requirements.
6.How does Aetrix verify that 25LC040AT-E/OT16KVAO is sourced from the original manufacturer or authorized distributors?
All 25LC040AT-E/OT16KVAO 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 25LC040AT-E/OT16KVAO meets industry standards.
7.What is the process for return or replacement of 25LC040AT-E/OT16KVAO?
All 25LC040AT-E/OT16KVAO units undergo pre-shipment inspection (PSI). If there is an issue with 25LC040AT-E/OT16KVAO, 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 25LC040AT-E/OT16KVAO part is unused and in its original packaging.
Return procedure for 25LC040AT-E/OT16KVAO:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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