STMicroelectronics M4T32-BR12SH1

Overview

M4T32-BR12SH from STMicroelectronics is a 4-pin SNAPHAT® top module integrating a 120 mAh lithium carbon monofluoride (Li(CF)) battery and 32.768 kHz crystal for real-time clock backup, designed to snap onto 28- or 44-pin SOIC TIMEKEEPER® devices after reflow soldering. It provides industrial-grade temperature operation (–40°C to +85°C), ±35 ppm crystal accuracy at 25°C, and 12.5 pF load capacitance - enabling reliable timekeeping in embedded industrial controllers and metering systems.

For engineers reviewing the M4T32-BR12SH datasheet, M4T32-BR12SH pinout, M4T32-BR12SH application, or M4T32-BR12SH equivalent, key selection criteria include battery capacity (120 mAh vs. 48 mAh in M4T28-BR12SH), operating temperature grade (Grade 6 only), mechanical retention under shock (>100 g), gold-plated socket contact reliability, and UL Component Recognition (E89556).

Technical Context

The M4T32-BR12SH is a passive, non-rechargeable mechanical-electrical interface module-not an IC-designed exclusively for mating with ST's serial RTC/SOIC TIMEKEEPER® packages. It delivers power and timing reference via four gold-plated press-fit pins (VBAT+, VBAT–, X1, X2) and uses redundant six-finger socket contacts per pin to ensure low-resistance, vibration-resistant connection.

Its mechanical design incorporates molded retaining clips that engage SOIC ends, enabling shock survivability >100 g and compliance with MIL-STD-883, method 2007.2. Battery discharge exhibits flat voltage profile (~2.8 V nominal) until end-of-life, with no mercury, cadmium, or lead content, and full encapsulation per environmental regulations.

Key Specifications

Pinout & Package

The M4T32-BR12SH is a 4-pin surface-mount SNAPHAT® housing (SH package) with molded-in retaining clips, designed for mechanical snap-on assembly to 28-/44-pin SOIC TIMEKEEPER® devices. Dimensions: 21.46 mm × 17.65 mm × 10.54 mm (L × W × H), with 15.75 mm pin pitch (eA) and 3.4 mm pin spacing (eB).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RTC backup and crystal integration applications.

Compared with M4T28-BR12SH, the M4T32-BR12SH offers 2.5× higher capacity and industrial temperature support - critical for long-life, wide-ambient deployments. Unlike integrated RTC+TCXO solutions (e.g., DS3231), it preserves modularity, serviceability, and legacy SOIC compatibility without board-level redesign.

Availability

M4T32-BR12SH is available at Aetrix Electronics and suitable for industrial smart metering, programmable logic controllers (PLCs), medical data loggers, and telecom base station clock holdover requiring stable component supply, long-lifecycle support, and field-replaceable RTC backup.

Supply support for M4T32-BR12SH 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, analog ICs, MEMS, and power management solutions for industrial, automotive, and consumer markets.

The M4T32-BR12SH belongs to ST's TIMEKEEPER® SNAPHAT® product line - engineered specifically to decouple RTC backup power and timing elements from SMT thermal stress while enabling field-serviceable, UL-recognized, and environmentally compliant timekeeping modules.

FAQ

Can M4T32-BR12SH be used with non-ST RTC SOIC packages?

No - the M4T32-BR12SH is mechanically and electrically optimized for ST's 28- and 44-pin SOIC TIMEKEEPER® devices (e.g., M41Txx, M48Txx series). Its 4-pin footprint, socket geometry, and keyed insertion align precisely with ST's SNAPHAT® socket dimensions and pin assignments (VBAT+, VBAT–, X1, X2). Interfacing with non-ST SOICs risks misalignment, poor contact, or damage to retaining clips.

What is the maximum insertion force allowed during assembly?

ST specifies a maximum insertion force of 40 pounds-force (lbf) to avoid battery damage or die cracking. The datasheet states that typical insertion requires <13 lbf, and manual presses must be calibrated to enforce this limit. Exceeding 40 lbf risks permanent deformation of the SNAPHAT® housing, compromised battery seal integrity, or fracture of the internal crystal element.

How is battery end-of-life detected in systems using this module?

The M4T32-BR12SH itself provides no voltage monitoring or alert signaling. End-of-life detection must be implemented externally - typically by the host RTC (e.g., M41T82) monitoring VCC level or by a supervisor IC tracking backup voltage threshold (e.g., 2.5 V). ST application note AN1012 defines data retention life based on load current and temperature, not on-module sensing.

Is the crystal inside M4T32-BR12SH replaceable or user-accessible?

No - the 32.768 kHz crystal is fully encapsulated and non-serviceable within the SNAPHAT® housing. It is permanently bonded and sealed alongside the Li(CF) battery during manufacturing. Attempting physical access would destroy the module, void UL recognition (E89556), and breach environmental compliance (RoHS, WEEE). Replacement requires swapping the entire M4T32-BR12SH unit.