STMicroelectronics M95256-DFMN6TP

Overview

M95256-DFMN6TP from STMicroelectronics is a 256-Kbit serial SPI EEPROM organized as 32,768 × 8 bits, supporting 1.7 V to 5.5 V single-supply operation across –40 °C to +85 °C. It features 64-byte page writes completing in ≤5 ms, 4 million write cycles, 200-year data retention, and an additional lockable 64-byte Identification page for secure parameter storage - deployed in industrial sensor calibration and automotive body control modules.

For engineers reviewing the M95256-DFMN6TP datasheet, M95256-DFMN6TP pinout, M95256-DFMN6TP application, or M95256-DFMN6TP equivalent, key selection criteria include supply voltage range (1.7–5.5 V), SPI mode compatibility (CPOL/CPHA = 0/0 or 1/1), hardware/software write protection granularity (quarter/half/full array), identification page lockability, and ECOPACK2-compliant WLCSP8 packaging.

Technical Context

The M95256-DFMN6TP implements a synchronous SPI interface with dual-mode clock polarity support (CPOL=0/CPHA=0 and CPOL=1/CPHA=1), where input data is latched on the rising edge of C and output data is valid on its falling edge. Its internal architecture includes a high-voltage generator, ECC-enabled sense amplifiers, and a dedicated status register with non-volatile BP1/BP0 and SRWD bits for configurable memory protection.

It integrates a power-on-reset (POR) circuit that prevents spurious writes during power-up, requires a falling edge on Chip Select (S) before first instruction acceptance, and supports Hold functionality to pause ongoing transfers without deselecting the device - all while maintaining high-impedance Q during Hold and preserving internal state except WEL/WIP bits upon forced deselect.

Key Specifications

Pinout & Package

Package: WLSCP8 (WLCSP8), 1.289 mm × 1.376 mm, ECOPACK2-compliant wafer-level chip-scale package with bottom-side solder bumps - optimized for space-constrained portable and automotive modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25SF041-SSHD-B and MX25U25635FZUI, the M95256-DFMN6TP uniquely combines ultra-small WLCSP8 packaging, 1.7 V operation, hardware-assisted write protection, and a permanently lockable Identification page - making it the only option among the three qualified for secure, space-constrained, low-voltage industrial calibration storage.

Availability

M95256-DFMN6TP is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control modules, smart energy metering, and medical diagnostic handhelds requiring stable component supply, long-lifecycle assurance, and ECOPACK2-compliant packaging.

Supply support for M95256-DFMN6TP 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 industrial, automotive, and consumer markets.

The M95256 series belongs to ST's serial EEPROM product line, engineered specifically for reliable, low-voltage, high-endurance non-volatile storage in safety-critical and space-constrained embedded systems - emphasizing data integrity, secure configuration, and extended operational lifetime.

FAQ

What is the function of the HOLD pin on M95256-DFMN6TP?

The HOLD pin pauses ongoing SPI communication without deselecting the device or resetting internal state. When asserted low (with S low), Q enters high-impedance, and D/C are ignored - enabling CPU context switches or interrupt servicing. The device resumes exactly where it left off upon HOLD deassertion, preserving clock phase and byte count. This behavior is validated in DS4712 Rev 22 Figure 7 and Section 5.3.

How does the Identification page differ from the main memory array?

The Identification page is a dedicated 64-byte memory region accessible only via RDID/WRID/LID instructions (not standard READ/WRITE). It supports permanent read-only locking via the LID command, making stored data (e.g., calibration keys) immutable after programming. Unlike main array protection, this lock is irreversible and hardware-enforced - confirmed in DS4712 Section 6 and Table 4 footnote 1.

Can M95256-DFMN6TP operate at 1.7 V during write operations?

Yes - the M95256-DF variant (including M95256-DFMN6TP) is fully specified for write operations down to 1.7 V, with guaranteed ≤5 ms page write time and full 4 million endurance cycle rating across the entire 1.7–5.5 V range. This is explicitly defined in Section 1 and Table 10 of DS4712 Rev 22, distinguishing it from the -W (-2.5 V min) and -R (-1.8 V min) variants.

What SPI modes does M95256-DFMN6TP support, and how are they configured?

M95256-DFMN6TP supports only two SPI modes: CPOL=0/CPHA=0 and CPOL=1/CPHA=1. Configuration is determined by the host controller's SPI peripheral settings - no device-side configuration is required. In both modes, data is latched on the rising edge of C and output on the falling edge. Mode selection depends solely on idle clock polarity (0 or 1), as detailed in DS4712 Section 4.1 and Figure 6.