STMicroelectronics M95640-DWDW4TP/K

Overview

M95640-DWDW4TP/K from STMicroelectronics is an automotive-grade 64-Kbit serial SPI EEPROM with TSSOP8-169mil package, rated for operation up to 145 °C and 5.5 V supply, supporting 20 MHz clock at V_CC ≥ 4.5 V, featuring 32-byte page write, block-level write protection (1/4, 1/2, or full memory), and a lockable 32-byte identification page. It serves as nonvolatile configuration storage in engine control units, ADAS sensors, and battery management systems.

For engineers reviewing the M95640-DWDW4TP/K datasheet, M95640-DWDW4TP/K pinout, M95640-DWDW4TP/K application, or M95640-DWDW4TP/K equivalent, key selection criteria include AEC-Q100 Grade 0 qualification, extended temperature endurance (145 °C), SPI timing compatibility (CPOL=0/1, CPHA=0/1), and hardware-based write protection via W and HOLD pins.

Technical Context

This device implements a true EEPROM array organized as 256 × 32-byte pages (8192 × 8 bits), with embedded ECC logic enhancing data integrity during read operations. It supports two SPI modes (CPOL=0,CPHA=0 and CPOL=1,CPHA=1), latching input on rising clock edge and outputting data on falling edge.

Write protection is enforced through non-volatile BP1/BP0 bits in the Status Register and hardware pin W, enabling configurable lock of memory blocks; the SRWD bit couples with W to freeze Status Register writes when W is low. The dedicated 32-byte Identification Page supports permanent locking via LID instruction for secure parameter storage.

Key Specifications

Pinout & Package

Package: TSSOP8 (DW), 169 mil width, 3 × 4.4 mm body, 0.65 mm pitch, RoHS-compliant and halogen-free (ECOPACK2®).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial SPI EEPROM applications.

Compared with AT25DF041A-SSH-T, M95640-DWDW4TP/K delivers certified automotive reliability and embedded ECC but at lower density; versus M95M02-DWDW4TP/K, it offers reduced cost and footprint for applications needing only 64 Kbit while retaining identical thermal and functional safety attributes.

Availability

M95640-DWDW4TP/K is available at Aetrix Electronics and suitable for engine control units, ADAS sensors, and battery management systems requiring stable component supply across extended temperature ranges and automotive lifecycle commitments.

Supply support for M95640-DWDW4TP/K 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and memory solutions for automotive, industrial, and consumer markets.

The M95xxx EEPROM product line targets automotive and industrial applications demanding AEC-Q100 qualification, extended temperature operation, and robust SPI interface performance in harsh environments.

FAQ

What is the maximum clock frequency supported by M95640-DWDW4TP/K at 3.3 V supply?

At V_CC = 3.3 V, the device supports up to 10 MHz clock frequency, as specified in the datasheet's operating conditions table (voltage range R, temperature range 3). This ensures reliable high-speed communication with common 3.3 V microcontrollers while maintaining timing margins across temperature.

How does the HOLD pin function during an active Write cycle?

The HOLD pin cannot pause an ongoing Write cycle (t_W); it only suspends SPI command transmission. If HOLD is asserted during a Write instruction, the device completes the current t_W (up to 4 ms), then enters Hold mode upon completion. No data corruption occurs, and the WIP bit remains set until t_W finishes.

Can the Identification Page be rewritten after being locked with the LID instruction?

No. Once the Lock Identification Page (LID) instruction is executed, the Identification Page becomes permanently read-only. The lock is irreversible and hardware-enforced; no command or voltage sequence can unlock or rewrite the page, ensuring tamper-proof storage of critical identifiers or keys.

What is the purpose of the SRWD bit in conjunction with the W pin?

The SRWD bit controls whether the Status Register (including BP1/BP0 and SRWD itself) can be modified via WRSR. When SRWD = 1 and W = low, Status Register writes are blocked - freezing memory protection settings. Pulling W high restores write capability, enabling dynamic reconfiguration of protection granularity during development or service.