STMicroelectronics M95040-DFMC6TG

Overview

M95040-DFMC6TG from STMicroelectronics is a 4-Kbit (512-byte) serial SPI bus EEPROM with 1.7 V to 5.5 V single-supply operation, 20 MHz max clock frequency, and an additional 16-byte identification page that supports permanent read-only lock. It features byte/page write times ≤5 ms, >4 million write cycles, and 200-year data retention - deployed in industrial control modules for firmware parameter storage and calibration data logging.

For engineers reviewing the M95040-DFMC6TG datasheet, M95040-DFMC6TG pinout, M95040-DFMC6TG application, or M95040-DFMC6TG equivalent, key selection criteria include its 1.7 V low-voltage operation, identification page lock capability, quarter/half/whole-array software write protection, ECC x1 bit-error correction, and ECOPACK2-compliant UFDFPN8 package.

Technical Context

This device implements a standard SPI interface with CPOL=0/CPHA=0 or CPOL=1/CPHA=1 mode support, using dedicated D (input), Q (output), and C (clock) lines synchronized on rising/falling edges respectively. Chip select (S) enables device selection and initiates instruction decoding only after a valid falling edge post-power-up.

The internal architecture includes an ECC x1 logic block per memory byte, transparently correcting single-bit errors during read operations. A non-volatile status register controls BP1/BP0 block protection bits and tracks WEL/WIP states, while the HOLD input allows pausing communication without interrupting the clock sequence or resetting internal state.

Key Specifications

Pinout & Package

Supplied in RoHS- and halogen-free UFDFPN8 (2 mm × 3 mm, MC variant) package per ECOPACK2 specification. Pin 1 marked by top-side dot; pin numbering follows standard counter-clockwise layout from top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25DF041A-SSH-T and M950040-DWDWG, the M95040-DFMC6TG uniquely combines 1.7 V operation, ECC x1, and lockable ID page in a 2×3 mm UFDFPN8 package - making it optimal for next-gen portable, low-power, and security-sensitive embedded systems.

Availability

M95040-DFMC6TG is available at Aetrix Electronics and suitable for industrial sensor calibration, smart meter firmware storage, automotive body control unit configuration, and medical device configuration requiring stable component supply across multi-year production cycles.

Supply support for M95040-DFMC6TG 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 management ICs, MEMS sensors, and non-volatile memory solutions for industrial, automotive, and consumer markets.

The M950x0 family delivers SPI-compatible EEPROMs optimized for robust, low-voltage, high-endurance data logging in space- and power-constrained embedded systems - emphasizing reliability, security, and seamless MCU integration.

FAQ

What is the function of the HOLD pin on the M95040-DFMC6TG?

The HOLD pin pauses ongoing SPI communication without deselecting the device or resetting internal state. When asserted low while chip select (S) is active, it forces Q into high-impedance and ignores D and C transitions. This enables time-critical MCU tasks to preempt EEPROM access while preserving transaction context - critical in real-time control loops where deterministic latency matters.

How does the identification page differ from standard memory array pages?

The identification page is a dedicated 16-byte segment accessible only via RDID/WRID instructions - separate from the main 512-byte array. Once locked via LID instruction, it becomes permanently read-only with no hardware or software override. Unlike standard pages, it cannot be erased or rewritten, making it suitable for storing immutable device identifiers or cryptographic keys required for secure boot or regulatory compliance.

Can the M95040-DFMC6TG operate reliably at 1.7 V during write operations?

Yes - the M95040-DFMC6TG is fully specified for write operations down to 1.7 V, with guaranteed ≤5 ms byte/page write times and full status register functionality across the entire 1.7–5.5 V range. Its internal charge pump and voltage regulation ensure consistent programming voltage generation even at minimum VCC, validated per DS1639 Rev 14 AC timing tables (tW, tWH, tWL).

What protection mechanisms prevent accidental writes during power-up or noise events?

Three layers prevent spurious writes: (1) Power-on-reset (POR) holds the device inactive until VCC exceeds VRES (~1.2 V); (2) Chip select (S) requires a clean falling edge after stabilization before accepting instructions; (3) Write Enable Latch (WEL) resets automatically on power-up, WRDI, or write completion - meaning every write must be explicitly enabled via WREN. Invalid instructions or misaligned S transitions are ignored, not executed.