STMicroelectronics M93S46-WMN6TP

Overview

M93S46-WMN6TP from STMicroelectronics is a 1 Kbit (64 × 16-bit) serial EEPROM with MICROWIRE bus interface, write protection register, and OTP lock capability. It operates from 2.5 V to 5.5 V, supports up to 2 MHz clock, delivers ≤5 ms page/byte write time, and guarantees >4 million write cycles with >200-year data retention over –40 °C to +85 °C - used in industrial sensor calibration storage and embedded system configuration memory.

For engineers reviewing the M93S46-WMN6TP datasheet, M93S46-WMN6TP pinout, M93S46-WMN6TP application, or M93S46-WMN6TP equivalent, key selection criteria include its 16-bit word organization, user-definable protected area via PRE/W control, ready/busy signaling on Q, SO8 ECOPACK®2 package compatibility, and MICROWIRE protocol timing compliance per Table 11 AC characteristics.

Technical Context

The M93S46-WMN6TP implements a synchronous serial MICROWIRE interface with start-bit–driven instruction framing, where op-code, address, and data are shifted MSB-first on rising C edges. All instructions require precise clock pulse counting (25 cycles for WRITE/READ) to reject noise-induced misalignment - validated by internal glitch-resistant counter logic.

It features dual-level write protection: dynamic control via W pin (low = global write disable) and persistent configuration via 6-bit Protection Register (accessed via PRWRITE/PRREAD), which can be permanently locked using a One-Time-Programmable bit. Memory is organized as 64 independent 16-bit words, with page size fixed at 4 words (64 bits).

Key Specifications

Pinout & Package

Package: SO8 ECOPACK®2 (150 mil body width, MN code), RoHS-compliant, surface-mount plastic small outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25010B-SSHL-T and M95010-WMN6TP, the M93S46-WMN6TP uniquely provides MICROWIRE compatibility, 16-bit word addressing, and field-programmable + OTP-locked protection register - essential for systems requiring deterministic instruction framing and multi-layer write security.

Availability

M93S46-WMN6TP is available at Aetrix Electronics and suitable for industrial sensor calibration, PLC configuration storage, and medical device safety parameter retention requiring stable component supply across extended product lifecycles.

Supply support for M93S46-WMN6TP 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 M93S46-W series belongs to ST's serial EEPROM product line, engineered specifically for robust, low-pin-count nonvolatile storage in resource-constrained embedded systems requiring noise-immune serial protocols and configurable write security.

FAQ

What is the function of the PRE pin on the M93S46-WMN6TP?

The PRE (Protection Register Enable) pin must be driven high before and during any instruction that accesses the Protection Register - including PRREAD, PRWRITE, PRCLEAR, PREN, and PRDS. It acts as a hardware gate to prevent accidental modification of write protection settings, ensuring that protection configuration changes require explicit dual-signal activation (PRE high + valid instruction).

Can the M93S46-WMN6TP be used with a 3.3 V microcontroller without level shifting?

Yes. The M93S46-WMN6TP supports VCC from 2.5 V to 5.5 V and specifies VIH = 0.7×VCC and VIL = 0.3×VCC, making it fully compatible with 3.3 V logic levels. Its SO8 package allows direct connection to 3.3 V GPIOs, provided VCC is supplied at 3.3 V and W/PRE/S inputs are driven within valid voltage thresholds per Table 10 DC characteristics.

How does the clock pulse counter prevent erroneous writes?

The internal clock pulse counter monitors the exact number of rising C edges from instruction start bit to S falling edge. If the count deviates from the expected value (e.g., 25 cycles for WRITE), the instruction is aborted and memory remains unmodified - rejecting noise-induced bit shifts or clock glitches that could corrupt address/data alignment, as demonstrated in Figure 3 of the datasheet.

Is the OTP bit reprogrammable after being set?

No. Once the One-Time-Programmable (OTP) bit is programmed (via PRDS instruction), it permanently locks the Protection Register content. This prevents any further writes to the register, including clearing or redefining the protected memory area. The OTP state is irreversible and survives all power cycles, ensuring permanent write protection enforcement.