STMicroelectronics M4Z28-BR00SH1

Overview

M4Z28-BR00SH from STMicroelectronics is a removable 48 mAh lithium carbon monofluoride (Li(CF)) SNAPHAT® battery top designed to provide backup power for 28-pin ZEROPOWER® SRAM SOIC packages. It snaps onto surface-mounted SOIC after reflow, avoids thermal exposure during soldering, features gold-plated dual-pin contact interface, and delivers nominal 2.8 V output with flat discharge profile up to end-of-life. Used in industrial memory retention systems requiring long-term data hold without battery degradation from assembly heat.

For engineers reviewing the M4Z28-BR00SH datasheet, M4Z28-BR00SH pinout, M4Z28-BR00SH application, or M4Z28-BR00SH equivalent, key selection criteria include snap-on mechanical retention force (≤13 lbf insertion), UL Component Recognition (E89556), ECOPACK® Pb-free compliance, 4-pin housing dimensions, and compatibility with ST's 28-pin ZEROPOWER® SRAM SOIC footprint.

Technical Context

The M4Z28-BR00SH is a passive, non-rechargeable battery module-not an IC or active circuit-designed exclusively as a detachable power source for ST's ZEROPOWER® SRAMs. Its electrical interface consists of two gold-plated pins (VBAT+ and VBAT−) engaging six-finger press-fit sockets on the SOIC, delivering stable 2.8 V at up to 48 mAh capacity with Li(CF) chemistry.

Mechanically, it uses four molded retaining clips to secure to the SOIC ends, sustaining >100 g shock and passing MIL-STD-883 method 2007.2 vibration testing. Insertion force stabilizes after 4–5 cycles (average ~12.5 lbf), and extraction requires a DIP extractor tool to prevent pin bending or socket damage.

Key Specifications

Pinout & Package

The M4Z28-BR00SH is a 4-pin SNAPHAT® housing (SH package) with molded plastic body and integrated BR1225 lithium coin cell. Dimensions: 21.4 mm × 14.6 mm × 6.7 mm (L × W × H), 6°–8° lead taper, gold-plated contact pins spaced 15.75 mm (eA) and 3.4 mm (eB) center-to-center.

Key Features

Applications

Availability

M4Z28-BR00SH is available at Aetrix Electronics and suitable for industrial PLCs, smart electricity meters, automotive infotainment systems, and medical diagnostic equipment requiring stable component supply with guaranteed long-term data retention capability.

Supply support for M4Z28-BR00SH 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, sensors, and analog/mixed-signal devices for industrial, automotive, and consumer markets.

The M4Z28-BR00SH belongs to ST's ZEROPOWER® SNAPHAT® battery family-engineered specifically to decouple non-volatile SRAM backup power from surface-mount thermal processes while ensuring mechanical robustness and regulatory compliance.

FAQ

Is the M4Z28-BR00SH compatible with all 28-pin SOIC ZEROPOWER® SRAMs?

No-it is mechanically and electrically matched only to ST's designated ZEROPOWER® SRAMs using the 28-pin SNAPHAT®-compatible SOIC footprint (e.g., M48Zxx series). Pin pitch, socket depth, and clip engagement geometry are proprietary to ST's SOIC design; third-party SOICs lack the required press-fit sockets and retention grooves.

Can the M4Z28-BR00SH be wave soldered or reflowed?

No-wave soldering or reflow will destroy the internal BR1225 lithium cell and melt the polymer housing. The device must be snapped onto the SOIC *after* all PCB assembly thermal processes are complete. ST explicitly cautions against wave soldering the SOIC to avoid socket damage.

What is the expected service life before battery replacement?

Under continuous 25°C operation with typical SRAM retention current (~1 µA), the 48 mAh capacity supports >10 years of data retention (per AN1012). Actual life depends on ambient temperature, load current, and storage conditions-capacity degrades ~2% per year at 25°C, accelerating above 60°C.

Does the M4Z28-BR00SH require special handling or disposal procedures?

Yes-this is a non-rechargeable lithium battery. It must not be incinerated, short-circuited, or placed in conductive foam. Disposal must comply with local regulations (e.g., US EPA 40 CFR Part 273) and battery manufacturer instructions. ST provides recycling symbols and ECOPACK® documentation for traceable end-of-life management.