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Microchip Technology 25CS640T-E/MWF36KVAO
- Part No.:
- 25CS640T-E/MWF36KVAO
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- -
- Datasheet:
-
25CS640T-E/MWF36KVAO.pdf
- Description:
- IC EEPROM 64KBIT SPI
- Quantity:
- Payment:
- Shipping:
Inventory:1,878
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Product details
Overview
25CS640T-E/MWF36KVAO from Microchip Technology is a 64-Kbit SPI Serial EEPROM organized as 8,192 × 8-bit with 32-byte page size, 4 ms max self-timed write cycle, and built-in ECC logic for single-bit error correction. It operates across 1.7V–5.5V, supports up to 20 MHz clock at VCC ≥4.5V, and includes a factory-programmed 128-bit serial number for secure device identification in automotive and industrial systems.
For engineers reviewing the 25CS640T-E/MWF36KVAO datasheet, 25CS640T-E/MWF36KVAO pinout, 25CS640T-E/MWF36KVAO application, or 25CS640T-E/MWF36KVAO equivalent, this page delivers verified electrical specs, JEDEC-compliant SPI ID support, dual write protection modes (Legacy/Enhanced), AEC-Q100 qualification, and real-world use cases in firmware storage, calibration data retention, and secure boot configuration.
Technical Context
The 25CS640T-E/MWF36KVAO implements a dedicated SPI interface compliant with Modes 0 and 3, latching input on SCK rising edge and outputting on falling edge. Its memory architecture comprises 256 pages of 32 bytes each, with separate nonvolatile Security register containing 128-bit read-only serial number and 32-byte user-programmable lockable ID page.
It integrates configurable undervoltage lockout (UVLO) via an 8-bit register, volatile STATUS register with WEL/ECS/WPM bits, four Memory Partition registers (MPR0–MPR3) enabling software- or hardware-based zone protection, and JEDEC-standard Identification register supporting Manufacturer ID, Device ID, and Extended Device Information reads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8,192 × 8-bit), organized in 256 pages of 32 bytes - enables efficient block writes and reduces command overhead in firmware update routines. |
| Write Cycle Time | ≤4 ms self-timed internal write - eliminates need for external timing control and simplifies host firmware polling logic. |
| Supply Voltage Range | 1.7V to 5.5V - supports direct interfacing with 1.8V, 2.5V, 3.3V, and 5V microcontrollers without level shifters. |
| Max Clock Frequency | 20 MHz at VCC ≥4.5V; 10 MHz at VCC ≥2.5V; 5 MHz at VCC ≥1.7V - ensures high-speed data logging while maintaining robustness across voltage corners. |
| ECC Capability | Corrects up to one bit error per 4-byte read - extends effective data retention beyond 200 years and improves reliability in harsh environments. |
| Temperature Range | −40°C to +125°C (Extended E grade) - qualified per AEC-Q100 Grade 1, suitable for under-hood automotive ECUs and industrial motor drives. |
| Endurance | 4 million erase/write cycles at +25°C - supports frequent parameter updates in telemetry, calibration, and configuration storage applications. |
Pinout & Package
25CS640T-E/MWF36KVAO is packaged in an 8-pin Wettable Flanks VDFN (Very Thin Dual Flat No-lead) with exposed thermal pad, optimized for automated optical inspection (AOI) and solder joint reliability in high-volume automotive PCB assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select Input | Active-low enable signal; must transition high-to-low to initiate SPI command sequence and low-to-high to terminate - controls device selection in multi-peripheral bus configurations. |
| SO | Serial Data Output | Tri-state output delivering MSb-first data on SCK falling edge; enters high-impedance when CS is high or HOLD is asserted - prevents bus contention during shared SPI operation. |
| WP | Write-Protect Pin | Hardware-controlled protection input; enables block-level or partition-level write inhibition depending on Legacy/Enhanced mode - provides fail-safe memory locking independent of software state. |
| VSS | Ground | Reference return path for all digital and analog circuitry; exposed pad (Pin 5) must be connected to PCB ground plane for thermal and EMI performance. |
| SI | Serial Data Input | MSb-first input accepting opcodes, addresses, and data on SCK rising edge - supports standard SPI framing without additional protocol translation. |
| SCK | Serial Clock Input | Asynchronous master-generated clock synchronizing all data transfers; compatible with SPI Modes 0 and 3 - allows seamless integration with most MCU SPI peripherals. |
| HOLD | Hold Input | Pauses ongoing SPI transaction without resetting internal state; allows host to service higher-priority interrupts - maintains address pointer and command context across hold/resume cycles. |
| VCC | Supply Voltage | Primary power rail; powers internal charge pump, ECC engine, and UVLO detection circuit - requires local 100 nF ceramic decoupling within 5 mm of pin. |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC SPI Manufacturer Read ID | Enables runtime device identification and firmware validation using standardized opcode 9Fh - eliminates hardcoded part assumptions in bootloader code. |
| Enhanced Write Protection Mode | Four independent memory partitions with programmable protection behavior (unprotected/software/hardware/locked) - supports secure firmware staging and immutable configuration zones. |
| Security Register | Factory-programmed 128-bit globally unique serial number + 32-byte user-lockable ID page - removes manufacturing serialization step and enables cryptographic key binding. |
| Undervoltage Lockout (UVLO) | Configurable threshold (1.4V–4.8V in 32 steps) via UVLO register - prevents corruption during brown-out events without external supervisor ICs. |
| AEC-Q100 Automotive Qualification | Qualified for Extended Temperature range (−40°C to +125°C) with 1,000-hour HTOL at +150°C - meets functional safety requirements for ASIL-B system data storage. |
Applications
| Automotive Engine Control Unit (ECU) | Industrial PLC Configuration Storage |
|---|---|
Use Scenario: Storing calibrated fuel injection maps, sensor offset compensation values, and diagnostic trouble codes (DTCs) that persist across ignition cycles. IC Role / Device Role / Timing Role: Nonvolatile configuration memory with ECC-protected read path and hardware WP pin tied to system safety monitor. Use Value: Ensures integrity of mission-critical calibration data over 200+ years, even after 4M write cycles and exposure to thermal cycling in under-hood environments. |
Use Scenario: Retaining I/O mapping tables, PID tuning parameters, and firmware update staging buffers in modular automation controllers. IC Role / Device Role / Timing Role: High-reliability SPI EEPROM interfaced directly to ARM Cortex-M7 MCU with no level shifting required. Use Value: Enables field-upgradable logic without requiring reprogramming tools - partitions allow safe dual-bank firmware swapping with hardware-enforced write lock. |
| Medical Infusion Pump Calibration | Smart Energy Meter Firmware Vault |
Use Scenario: Securing drug delivery rate profiles, operator access logs, and regulatory audit trails in Class II medical devices. IC Role / Device Role / Timing Role: Secure storage element with preprogrammed 128-bit serial number used as entropy source for TLS certificate generation. Use Value: Meets IEC 62304 traceability requirements by binding calibration data to unique device identity - prevents cloning and unauthorized parameter modification. |
Use Scenario: Holding metrology firmware signatures, tariff schedule tables, and tamper-event logs in ANSI C12.22-compliant smart meters. IC Role / Device Role / Timing Role: AEC-Q100-qualified EEPROM operating at 125°C ambient, interfaced to TI MSP430FR5994 via SPI Mode 0. Use Value: Guarantees >200-year data retention for billing records and supports secure firmware validation using JEDEC ID + ECC-corrected reads. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Serial EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT25DF641A-MAU-T | 64-Mbit NOR Flash (not EEPROM); lacks ECC, serial number, and UVLO; requires sector erase before write. | Not suitable for byte-write-intensive calibration storage; better for firmware image storage only. | Select only if application requires larger capacity and can tolerate erase-before-write latency. |
| 25AA640A-I/SN | Legacy Microchip 64-Kbit EEPROM; no ECC, no 128-bit serial number, no Enhanced Write Protection, max 10 MHz @ 2.5V. | Lacks security and reliability features needed for automotive or medical use; limited to cost-sensitive consumer designs. | Choose only for legacy compatibility where ECC, serialization, and AEC-Q100 are not required. |
Compared with AT25DF641A-MAU-T and 25AA640A-I/SN, the 25CS640T-E/MWF36KVAO uniquely combines ECC-based data integrity, factory-serialized identity, dual-mode write protection, and AEC-Q100 qualification - making it the only option among the three validated for safety-critical automotive and medical firmware storage.
Availability
25CS640T-E/MWF36KVAO is available at Aetrix Electronics and suitable for automotive ECU design, industrial PLC configuration management, and medical device calibration storage requiring stable component supply across extended temperature and long product lifecycles.
Supply support for 25CS640T-E/MWF36KVAO 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 microcontroller, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, communications, and consumer markets with vertically integrated silicon and software platforms.
The 25CS640 series is designed specifically for high-reliability, security-aware nonvolatile memory applications in automotive and industrial systems - emphasizing ECC resilience, cryptographic identity, and programmable voltage supervision.
FAQ
What is the operating voltage range for the 25CS640T-E/MWF36KVAO?
The 25CS640T-E/MWF36KVAO operates from 1.7V to 5.5V, supporting direct connection to 1.8V, 2.5V, 3.3V, and 5V logic domains. At 1.7V minimum, it sustains 5 MHz SPI clocking; at 4.5V or higher, it achieves full 20 MHz throughput. This wide range eliminates level-shifting components in mixed-voltage systems.
Does the 25CS640T-E/MWF36KVAO include error correction capability?
Yes, the 25CS640T-E/MWF36KVAO incorporates built-in Error Correction Code (ECC) logic that corrects up to one bit error per 4-byte read. An ECC Status bit in the STATUS register indicates whether correction occurred during the last read. This extends effective data retention beyond 200 years and enhances reliability in thermally stressed environments.
How does the Security register function in the 25CS640T-E/MWF36KVAO?
The 25CS640T-E/MWF36KVAO Security register contains two sections: a read-only 128-bit factory-programmed serial number (bytes 0–15), globally unique across all CS-series EEPROMs, and a 32-byte user-programmable, lockable ID page (bytes 32–63). Once locked via software command, the ID page becomes permanently read-only - ideal for binding cryptographic keys or calibration certificates to hardware identity.
What write protection modes does the 25CS640T-E/MWF36KVAO support?
The 25CS640T-E/MWF36KVAO supports two distinct write protection schemes: Legacy mode uses BP[1:0] bits in the STATUS register to protect quarter/half/entire memory array, while Enhanced mode employs four Memory Partition registers (MPR0–MPR3) to define up to four independently configurable zones with software/hardware lock options. Both modes coexist and can be selected via the WPM bit.
Is the 25CS640T-E/MWF36KVAO qualified for automotive applications?
Yes, the 25CS640T-E/MWF36KVAO is AEC-Q100 qualified for Extended Temperature Grade E (−40°C to +125°C) and tested for 1,000 hours at +150°C. It meets automotive reliability requirements including >4 million write cycles, >200-year data retention, and ESD tolerance >4 kV - making it suitable for engine control, ADAS, and body electronics subsystems.
25CS640T-E/MWF36KVAO Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- -
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 64Kbit
- Memory Organization:
- 8K x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 20 MHz
- Write Cycle Time - Word, Page:
- 4ms
- Access Time:
- 20 ns
- Voltage - Supply:
- 1.8V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
25CS640T-E/MWF36KVAO FAQ
1.How can I place an order for 25CS640T-E/MWF36KVAO through Aetrix?
Please submit a Request for Quotation (RFQ) for 25CS640T-E/MWF36KVAO 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 25CS640T-E/MWF36KVAO reliable?
The price and inventory of 25CS640T-E/MWF36KVAO are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25CS640T-E/MWF36KVAO is usually 5 days.
3.What payment methods are accepted for 25CS640T-E/MWF36KVAO?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25CS640T-E/MWF36KVAO transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 25CS640T-E/MWF36KVAO?
25CS640T-E/MWF36KVAO orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 25CS640T-E/MWF36KVAO 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 25CS640T-E/MWF36KVAO?
For technical support, including 25CS640T-E/MWF36KVAO datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25CS640T-E/MWF36KVAO requirements.
6.How does Aetrix verify that 25CS640T-E/MWF36KVAO is sourced from the original manufacturer or authorized distributors?
All 25CS640T-E/MWF36KVAO 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 25CS640T-E/MWF36KVAO meets industry standards.
7.What is the process for return or replacement of 25CS640T-E/MWF36KVAO?
All 25CS640T-E/MWF36KVAO units undergo pre-shipment inspection (PSI). If there is an issue with 25CS640T-E/MWF36KVAO, 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 25CS640T-E/MWF36KVAO part is unused and in its original packaging.
Return procedure for 25CS640T-E/MWF36KVAO:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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