STMicroelectronics M48T37V-10MH6F

Overview

M48T37V-10MH6F from STMicroelectronics is a 256 Kbit (32 K × 8) battery-backed TIMEKEEPER® SRAM integrating ultra-low-power real-time clock, power-fail control, watchdog timer, programmable alarm, and microprocessor reset - all in a single monolithic IC. It operates at 3.0–3.6 V, features VPFD of 2.7–3.0 V, supports 7-year data retention on internal lithium battery, and delivers BCD-formatted time/date registers accessible via standard SRAM interface.

For engineers reviewing the M48T37V-10MH6F datasheet, M48T37V-10MH6F pinout, M48T37V-10MH6F application, or M48T37V-10MH6F equivalent, this device serves as a drop-in timekeeping + nonvolatile memory solution for industrial control panels, medical instrumentation, energy meters, and legacy embedded systems requiring guaranteed RTC operation during main power loss.

Technical Context

The M48T37V-10MH6F integrates a 32,768 Hz crystal oscillator, BiPORT™ SRAM array, voltage-sensing switchover circuitry, and clock register update logic on one die. Its VPFD window (2.7–3.0 V) triggers automatic write protection and battery backup activation below VSO, while the RST open-drain output provides power-on reset valid even in battery mode.

Timekeeping registers (7FF1h–7FFFh) store century, year, month, date, day, hour, minute, second in 24-hour BCD format with leap-year correction through 2100. The IRQ/FT pin functions as either alarm interrupt or frequency test output, and the WDI input enables external watchdog supervision independent of clock domain.

Key Specifications

Pinout & Package

Package: 44-pin SOIC (SOH44), designed for top-mount SNAPHAT® housing (e.g., M4T32-BR12SH) containing integrated 32.768 kHz crystal and lithium coin cell. Gold-plated sockets enable reliable post-reflow mechanical/electrical connection without thermal stress to battery/crystal.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery-backed RTC+SRAM applications.

Compared with DS1307+AT24C256, M48T37V-10MH6F reduces component count and eliminates I²C timing dependencies; versus M48T59Y-70MH6E, it enables direct 3.3 V integration without level shifters but trades memory capacity for voltage compatibility.

Availability

M48T37V-10MH6F is available at Aetrix Electronics and suitable for industrial control panels, medical diagnostic devices, smart energy meters, and legacy embedded gateways requiring stable component supply with long-term lifecycle support.

Supply support for M48T37V-10MH6F 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 specializing in microcontrollers, power management, sensors, and analog chips for automotive, industrial, and consumer markets.

The TIMEKEEPER® product line delivers integrated RTC+memory solutions optimized for reliability-critical applications where time continuity, data integrity, and long-term battery operation are mandatory.

FAQ

What is the function of the SNAPHAT® housing, and is it included with M48T37V-10MH6F?

The SNAPHAT® housing (e.g., M4T32-BR12SH) contains the 32.768 kHz crystal and lithium coin cell, and mounts directly onto the SOH44 package via gold-plated sockets. It is not included with M48T37V-10MH6F - both components are ordered separately per ST's packaging scheme to avoid thermal damage during reflow soldering.

How does the M48T37V-10MH6F handle leap-year calculation?

The internal clock logic automatically corrects for February lengths (28 or 29 days) through year 2100 using built-in calendar arithmetic. This occurs transparently during the once-per-second register update - no host firmware intervention is required to maintain calendar accuracy across leap years.

Can the IRQ/FT pin be used simultaneously for alarm and frequency test functions?

No - the IRQ/FT pin is software-configurable for one function at a time. Setting the FT bit (D1 of seconds register 7FF9h) enables 32.768 kHz square wave output for clock calibration; clearing it restores alarm interrupt functionality. Both modes share the same open-drain driver and cannot operate concurrently.

What happens to the RTC during a WRITE cycle to SRAM memory locations outside the time registers?

The RTC continues uninterrupted. Only the BiPORT™ time registers (7FF1h–7FFFh) are updated once per second by dedicated hardware logic. Standard SRAM writes to other addresses have no effect on oscillator operation, timekeeping accuracy, or battery current draw - the two functions are electrically and logically isolated.