STMicroelectronics M93C46-WMN6P

Overview

M93C46-WMN6P from STMicroelectronics is a 1-Kbit MICROWIRE™-interface serial EEPROM with dual x8/x16 organization, operating from 2.5 V to 5.5 V over –40 °C to +85 °C, supporting up to 2 MHz clock and delivering byte/page write within 5 ms. It serves as nonvolatile configuration storage in microcontroller-based industrial control modules where space-constrained SO8N packaging and reliable 4 million write cycles are required.

For engineers reviewing the M93C46-WMN6P datasheet, M93C46-WMN6P pinout, M93C46-WMN6P application, or M93C46-WMN6P equivalent, key selection considerations include its MICROWIRE™ bus compatibility, ORG-selectable memory width, READY/BUSY signaling during programming, 200-year data retention, and ECOPACK2-compliant SO8N package footprint.

Technical Context

The M93C46-WMN6P implements a static CMOS MICROWIRE™ interface with synchronous serial communication using S (Chip Select), C (Clock), D (Data In), Q (Data Out), and ORG (Organization Select) signals. Its internal logic decodes 6-bit addresses for x16 mode or 7-bit addresses for x8 mode, and supports seven instruction types including READ, WRITE, WEN/WDS, ERASE, ERAL, and WRAL.

It features an on-chip clock pulse counter that validates instruction length against expected cycle counts (e.g., 25 cycles for WRITE in x16 mode), aborting misaligned commands to prevent corruption. A built-in power-on reset (POR) circuit ensures safe initialization, and the DU (Do Not Use) pin is reserved for factory test and must be left unconnected, tied to VCC, or grounded.

Key Specifications

Pinout & Package

Package: SO8N (150 mil width), ECOPACK2-compliant, surface-mount plastic small-outline package with gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT93C46D-SSH-T and M93C46-WDW6TP, the M93C46-WMN6P offers guaranteed SO8N compatibility, explicit DU pin documentation for test-aware designs, and ST's industrial-grade qualification across –40 °C to +85 °C with 4 M write cycles - making it optimal for fixed-voltage, high-reliability industrial control.

Availability

M93C46-WMN6P is available at Aetrix Electronics and suitable for industrial sensor calibration storage, embedded system boot configuration, and smart meter firmware parameter backup requiring stable component supply, long-lifecycle support, and ECOPACK2-compliant packaging.

Supply support for M93C46-WMN6P 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 products for industrial, automotive, and consumer markets.

The M93C46-WMN6P belongs to ST's M93Cx6-W series of MICROWIRE™ EEPROMs, engineered specifically for robust, low-pin-count nonvolatile storage in space- and reliability-constrained embedded systems.

FAQ

What is the function of the DU pin on M93C46-WMN6P?

The DU (Do Not Use) pin is reserved exclusively for STMicroelectronics factory testing and has no functional role in normal operation. It may be left unconnected, tied to VCC, or tied to VSS - none of these connections affect device behavior. Leaving it floating is not recommended due to potential noise coupling.

How does the ORG pin affect memory addressing in M93C46-WMN6P?

When ORG is high (or unconnected), the device operates in x16 mode with 6-bit addressing (64 words); when ORG is low, it operates in x8 mode with 7-bit addressing (128 bytes). The ORG state must be stable before entering standby mode to minimize quiescent current, and cannot be changed dynamically during operation.

Can M93C46-WMN6P be used with a 1.8 V supply?

No - the M93C46-WMN6P is part of the '-W' variant, specified for 2.5 V to 5.5 V operation. For 1.8 V compatibility, ST offers the '-R' variant (e.g., M93C46-RMN6P), which shares identical pinout and instruction set but extends VCC down to 1.8 V while maintaining the same -40 °C to +85 °C temperature range.

What happens if the Chip Select (S) signal is deasserted mid-write?

If S is taken low before the final clock edge of a WRITE instruction, the self-timed programming cycle will not initiate and no memory location is altered. If S is held high throughout the full instruction frame but dropped prematurely during the internal 5 ms write, the operation aborts and memory contents remain unchanged - the READY/BUSY signal remains low until completion or timeout.